WO2010008577A2

WO2010008577A2 - Methods for protecting exterior surfaces from corrosion, biofouling, and particulate erosion

Info

Publication number: WO2010008577A2
Application number: PCT/US2009/004134
Authority: WO
Inventors: Michael M. Pozvonkov; Ii D. Morgan Spears; Mark A. Deininger; Leonid V. Budaragin; Arvid E. Pasto
Original assignee: C3 International, Llc
Priority date: 2008-07-17
Filing date: 2009-07-17
Publication date: 2010-01-21
Also published as: EP2315861A2; WO2010008577A3

Abstract

The invention relates to method for forming at least one metal oxide on one or more exterior surfaces of fluid transport or processing systems, infrastructure systems, or components thereof, or on a surface subject to particulate erosion. The method involves applying at least one metal compound to the exterior surfaces to be treated. Then, the at least one metal compound is converted to at least one metal oxide, such as by heating the surfaces. In some embodiments, the at least one metal oxide provides a metal oxide coating adhered to those surfaces that reduces or prevents corrosion, biofouling, particulate erosion, or a combination thereof. Embodiments of the present invention can be performed in situ on existing systems, at the point of manufacture, or otherwise.

Description

In The US/RO:

International Patent Application Filed under the Patent Cooperation Treaty

For

METHODS FOR

PROTECTING EXTERIOR SURFACES FROM CORROSION, BIOFOULING, AND PARTICULATE EROSION

By

Michael M. Pozvonkov,

D. Morgan Spears II,

Mark A. Deininger,

Leonid V. Budaragin, and

Arvid E. Pasto RELATED APPLICATION

[0001] This application claims benefit of priority under PCT Chapter I, Article 8, and

35 U.S.C. § I I9(e) of U.S. Provisional Application No. 61/081,416, entitled "METHODS FOR PROTECTING EXTERIOR SURFACES FROM CORROSION AND BIOFOULING," filed on July 17, 2008, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] This invention relates to processes for applying coatings to man-made surfaces that are vulnerable to corrosion and/or biofouling, including industrial process and transport equipment and infrastructure.

DESCRIPTION OF THE RELATED ART

[0003] Metals, ceramics, glasses, and cermets are used to construct many functional items that are in turn used in carrying out industrial processes, support transportation of people and goods, or provide infrastructure such as roads, railways, bridges, and buildings. Under certain conditions, surface degradation of a component can result from many causes. These can include the corrosive nature of particular process conditions, thermal effects of the process or environment, contamination from various elements becoming deposited on the surface or infiltrating into the material, galvanic activity between the component's material and the environment, crevice corrosion, deposit and growth of life forms that may scavenge the surface for nutrients, and a combination of these degradation mechanisms with each other or with other mechanisms.

[0004] Portions of fluid processing and transport systems exposed to the environment suffer corrosion from several vectors. Chemical, thermal, and galvanic attack represent leading mechanisms of exterior surface corrosion in those systems. Those mechanisms derive from process conditions, environmental factors, and combinations thereof. Also, portions of such systems "exterior" to the processes they support can experience highly corrosive environments, even if those portions are not directly exposed to the weather. The repairing of such problems has large associated costs due to interrupted production while sections of a process system are identified and then cleaned, bypassed, and/or replaced. The petroleum industry, for example, has literally thousands of miles of connective pipelines, tubes, manifolds, as well as thousands of heat exchangers and process risers, etc. that require regular maintenance and repair at great costs to the industry. [0005] Many systems useful for military and aeronautical purposes are subject to corrosion, both from the environment and from the chemicals and materials they handle. For example, surfaces exposed to propellants, explosives, fuels, and combustion products thereof face chemical and thermal attack. Gun barrels, missile launch structures, ordinance handling, storage, and transportation equipment, and fuel handling, storage, and transportation equipment are especially vulnerable.

[0006] Prior art surface coatings for industrial process systems often fall short of providing corrosion or biofouling protection for many processes, particularly those involving high temperatures or highly caustic materials or a combination thereof. Particularly, there exists a need in industry for a surface coating that can be applied to an assembled process system with minimum disruption to the industrial plant and with minimum downtime, and which results in a coating that is resistant to highly deleterious conditions. An additional limitation of the current art in pipe coatings is the thickness of the final protective layer. Due to the wide temperature swings present in many industrial processes, the mismatch in coefficient of thermal expansion between the pipe material and the coating material typically results in cracking and spalling of current coatings, especially for thicker coatings. Furthermore, thicker coatings inhibit the transfer of heat across the pipe wall. The lower thermal conductivity of, for example, a heater tube wall requires higher temperatures and consumes more energy to achieve a given process temperature inside the tube. That higher temperature also pushes some components closer to their metallurgical limits, facilitating creep and other damage mechanisms, facilitating damage and failure and reducing service lifetime.

[0007] In addition, infrastructure systems must endure relative extremes of environmental heat and cold, thermal expansion and contraction, direct sunlight, precipitation, ice formation, salt and other de-icing chemicals, colonization by various plants, animals, microbes, and other organisms, and corrosive attack from atmospheric pollutants. Infrastructure built near sea water faces particularly harsh environments. Paint and other protective measures provide an incomplete or inadequate remedy. [0008] Transportation equipment, including cars, trucks, trains, planes, and ships, must withstand similarly difficult conditions. In addition to corrosion by chemical species in the environment, biofouling, such as by algae, limpets, mussels, barnacles, seaweed, bryozoans, and bacteria, has proven to be a major problem especially for the shipping industry. Such debris adds weight, reduces hydrodynamic efficiency, and adds fuel costs to operate any waterborne craft. Anti-biofouling compounds such as tributyl tin and triphenyl tin have proven to be toxic to the environment. Muntz metal, other forms of brass, and even copper plating have been used historically to combat marine biofouling; however, using those metals has proven to be prohibitively expensive. The marine shipping industry alone spends billions of dollars each year to combat biofouling.

[0009] In addition, particulate erosion damages infrastructure, components of industrial systems, and vehicles, thereby increasing maintenance costs and shortening service lifetimes. Wind- and water-driven sand, dust, and silt cause microscopic surface damage that can lead to mechanical erosion of the surface and eventual material failure if left unchecked. Particulate erosion occurs in natural environments, such as those where particles driven by wind or water impact surfaces. Particulate erosion also occurs in industrial processes wherever particulate matter strikes manufactured surfaces such as screens, conduits, impellors, reactors, transport equipment, and storage equipment. Particulate erosion in concert with corrosion and/or biofouling synergistically shorten the service lives of useful surfaces.

[0010] There exists, therefore, the need for an improved means of protecting the surfaces in many functional and structural components from a variety of contaminants that build up or chemical erosion that occurs, through various mechanisms, during the component's normal operation. An improved surface treatment that can be affordably applied and that provides a demonstrable resistance to surface contamination would serve to improve many processes currently in use throughout industry. The invention disclosed herein addresses this need.

DESCRIPTION OF THE INVENTION

[0011] Various embodiments of the present invention are described herein. These embodiments are merely illustrations of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0012] Corrosion can be caused by many mechanisms, including but not limited to chemical, thermal, and/or galvanic attack. Corrosion is indicated by numerous observations including but not limited to chemical transformation of the surface such as by oxidation and scaling, non-biological material depositing on a surface, one or more materials infiltrating the surface, and/or by erosion of the surface. Corrosion includes, therefore, all forms of microfouling except biofouling. The invention relates, therefore, in some embodiments, to methods for preventing or reducing corrosion on an exterior surface, comprising applying at least one metal compound to the surface; and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide, wherein the at least one metal oxide is resistant to corrosion. [0013] An exterior surface is any man-made surface that is exposed to the elements.

In certain embodiments, the "elements" to which a surface is exposed includes any natural, any man-made, or combinations thereof, corrosive or degrading agent or agents, including but not limited to water, oxygen, air, wind, sun, heat, cold, ice, other frozen water, de-icing salt, sea salt, other de-icing chemicals, pollutants, industrial effluent of any kind, biofouling organisms such as bacterial, algae, limpets, mussels, barnacles, seaweed, and bryozoans, and the like, including any of the foregoing alone or in combination. An exterior surface is not limited by its location. For example, the "inside" of a bridge's expansion joint is an exterior surface, because that surface is exposed to the elements.

[0014] Biofouling, to be distinguished from corrosion, consists of one or more organisms, and one or more species of organisms, attacking and degrading a surface. In some cases, biofouling results from the organism living on the surface. In other cases, residues and/or surface degradation left behind by the organism constitute biofouling. Thus, other embodiments of the present invention provide a method for preventing or reducing biofouling on an exterior surface, comprising: applying at least one metal compound to the surface; and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide on the surface. [0015] Particulate erosion, as its name suggests, relates to the physical degradation of a surface due to impacts of particles. It can be caused by, among other things, sand, dust, silt, pebbles, hail, other solid or liquid precipitation, and industrial solids such as powders, pellets, and the like. The particles can be any size, for example, less than about I O cm in diameter, less than about I cm, less than about I mm, less than about 500 microns, less than about 100 microns, less than about I O microns, less than about I micron, less than about 500 nm, or less than about 100 nm, in some embodiments. The particles can be driven by any suitable force such as that provided by a carrier fluid such as a gas (air, inert gas, steam) or a liquid (water, solvent), by gravity, or by combinations of the foregoing.

[0016] Some methods of the invention protect exterior surfaces by inhibiting or preventing degradation, irrespective of whether the degradation occurs through deposition of material on the surfaces, through infiltration of material into the surfaces, through erosive attack, or through biological processes. The method is adapted to be used, in some embodiments, on equipment before, during, and/or after assembly, or in connection with maintenance, or even when recycling after the expected service life of the equipment has passed.

[0017] The present invention relates, in some aspects, to forming at least one metal oxide on an exterior surface. The at least one metal oxide can be formed on the surface by (I) placing at least one metal compound on the surface and (2) converting at least some of the at least one metal compound into at least one metal oxide.

[0018] Some embodiments provide a method for forming at least one metal oxide on a surface subject to a high-temperature environment, comprising applying at least one metal compound to the surface, and converting at least some of the at least one metal compound into at least one metal oxide, wherein the at least one metal oxide withstands the high- temperature environment. Certain of those embodiments are exterior surfaces, while other embodiments relate to interior surfaces exposed to a high-temperature environment. [0019] Metal compounds useful in the present invention contain at least one metal atom and at least one oxygen atom. Non-limiting examples of useful metal compounds include metal carboxylates, metal alkoxides, and metal β-diketonates. Converting the metal compound can be accomplished by a wide variety of methods, such as, for example, heating the environment around the metal compound, heating the substrate under the metal compound, heating the metal compound itself, or a combination of those three. In other embodiments, converting the metal compound can be accomplished by catalysis. [0020] Some embodiments of the present invention provide a method for forming at least one metal oxide on an exterior surface of a partially-assembled system or a component thereof, comprising: applying at least one metal compound to the surface; and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide. A system is any man-made useful assembly, and can be a machine, a piece of equipment, an industrial process unit, a pipeline, a ship's hull, a bridge, a building, a subunit of any of the foregoing, and the like. In other embodiments, the system is substantially assembled prior to forming at least one metal oxide coating on at least one exterior surface of the system. In still other embodiments, the system is fully assembled prior to forming at least one metal oxide coating on at least one surface of the system. In yet other embodiments, the system is partially assembled prior to forming at least one metal oxide coating on at least one exterior surface of the system. Still further embodiments provide that one or more components of the system have at least one metal oxide coating formed on at least one exterior surface thereof when the component is not assembled into the system. In some cases, the component is newly-manufactured. In other cases, the component is disassembled from the system, treated to form at least one metal oxide coating on at least one exterior surface, and then reassembled into that system or into another system.

[0021] Further embodiments of the present invention provide a method for forming at least one metal oxide on a surface subject to particulate erosion, comprising: applying at least one metal compound to the surface; and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide. A surface subject to particulate erosion is any surface that can be impacted by particles. Such surfaces can be exterior surfaces or interior surfaces, as applicants have unexpectedly found that certain embodiments of the present invention provide here-to-fore unavailable protection for industrial equipment that handles particulate matter. [0022] In some embodiments, the invention relates to a method for forming at least one metal oxide on an exterior surface of a system, or a component thereof, or on a surface subject to particulate erosion, comprising: applying a metal compound composition to the surface, wherein the metal compound composition comprises at least one metal salt of at least one carboxylic acid; and exposing the surface with the applied metal compound composition to an environment that will convert at least some of the salt to at least one metal oxide. [0023] In certain embodiments, the invention relates to a method for forming at least one metal oxide on an exterior surface of a system, or a component thereof, or on a surface subject to particulate erosion, comprising: applying a metal compound composition to the surface, wherein the metal compound composition comprises at least one metal alkoxide; and exposing the surface with the applied metal compound composition to an environment that will convert at least some of the metal alkoxide to at least one metal oxide. [0024] In other embodiments, the invention relates to a method for forming at least one metal oxide on a surface of an exterior surface of a system, or a component thereof, or on a surface subject to particulate erosion, comprising: applying a metal compound composition to the surface, wherein the metal compound composition comprises at least one metal β- diketonate; and exposing the surface with the applied metal compound composition to an environment that will convert at least some of the metal β-diketonate to at least one metal oxide.

[0025] In further embodiments, the invention relates to a method for forming at least one metal oxide on an exterior surface of a system, or a component thereof, or on a surface subject to particulate erosion, comprising: applying a metal compound composition to the surface, wherein the metal compound composition comprises at least one rare earth metal compound, and at least one transition metal compound; and exposing the surface with the applied metal compound composition to an environment that will convert at least some of the compounds to at least one metal oxide.

[0026] In some embodiments of methods of forming at least one metal oxide on an exterior surface of a system or component thereof, or on a surface subject to particulate erosion, the at least one metal oxide comprises a metal oxide coating or metal oxide film. A metal oxide coating or a metal oxide film, in some embodiments, is crystalline, nanocrystalline, amorphous, thin film, or infused, or a combination of any of the foregoing. For example, a metal oxide coating in some embodiments of the present invention may comprise a film that contains both nanocrystalline and amorphous regions. In some embodiments, a metal oxide coating or metal oxide film at least partially infuses or penetrates into exterior surfaces of the system thereby precluding any intermediate bonding layers. [0027] The invention, in additional embodiments, relates to a method for forming at least one metal oxide on an exterior surface of a system, or a component thereof, or on a surface subject to particulate erosion, comprising: applying a liquid metal compound composition to the surface, wherein the liquid metal compound composition comprises a solution of at least one rare earth metal compound and at least one transition metal compound, in a solvent, and exposing the surface with the applied liquid compound to a heated environment that will convert at least some of the metal compound to at least one metal oxide, thereby forming a metal oxide coating on the surface.

[0028] As provided herein, in some embodiments, the metal oxide coating may be crystalline, nanocrystalline, amorphous, thin film, or infused, or a combination of any of the foregoing. For example, a metal oxide coating in some embodiments of the present invention may comprise a thin film that contains both nanocrystalline and amorphous regions. [0029] In other embodiments, the invention relates to metal oxide coatings (and articles coated therewith) containing two or more rare earth metal oxides and at least one transition metal oxide. Further embodiments of the invention relate to metal oxide coatings (and articles coated therewith), containing ceria, a second rare earth metal oxide, and a transition metal oxide. Some embodiments relate to metal oxide coatings (and articles coated therewith), containing yttria, zirconia, and a second rare earth metal oxide. [0030] Some embodiments of the invention create a protective metal oxide coating on a chosen exterior surface to serve as a prophylaxis against attack from chemical, thermal, and/or galvanic corrosion.

[0031] Further embodiments of the invention create a protective metal oxide coating on a chosen surface subject to particulate erosion to serve as a prophylaxis against attack from repeated impact of particulate matter.

[0032] Other embodiments of the present invention provide a method for reducing or preventing corrosive attack on an exterior surface of a system, or a component thereof, comprising applying at least one metal compound to the surface, and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide, wherein the at least one metal oxide is resistant to corrosive attack.

[0033] In another embodiment, the at least one metal oxide is operable to render an exterior surface of a system treated therewith resistant to corrosion for a period of at least months or years.

[0034] Some embodiments of the invention provide an improved corrosion-resistant surface treatment through the creation of a nanocrystalline grain structure of zirconia- or cerium-based materials, or surface treatments of other elemental compositions with nanocrystalline microstructures that serve to isolate the substrate from chemical, thermal, or galvanic attack.

[0035] Additional embodiments provide a low cost means to form a useful coating of zirconia- or ceria-based ceramic material on a substrate, the coating having a nanocrystalline microstructure.

[0036] Some embodiments of the technology will prevent electrochemical corrosion by inhibiting the flow of electrons or ions into or from the exterior surface and from or into the environment.

[0037] Additional embodiments of the invention produce a dense metal oxide coating that does not suffer from cracking due to thermal stresses.

[0038] Some embodiments produce a metal oxide coating that does not suffer from cracking due to its fabrication method.

[0039] Other embodiments provide a surface exhibiting greater resistance to particulate erosion compared to an otherwise identical surface without the embodiment.

[0040] In further embodiments, the at least one metal oxide coating appears uniform and without cracks or holes from about 10Ox to about 100Ox magnification. [0041] Some embodiments provide a metal oxide coating comprising only one metal oxide. Other embodiments provide a metal oxide coating comprising only two metal oxides. Still other embodiments provide a metal oxide coating comprising only three metal oxides. In yet other embodiments, the metal oxide coating comprises four or more metal oxides. [0042] The present invention, in some cases, also provides a low cost method for the creation of a metal oxide coating that serves to protect an exterior surface from chemical, thermal, and/or galvanic attack, or from biofouling, or to protect a surface from particulate erosion. The present invention also provides a means to infuse chosen surfaces with selected chemical ingredients using a process that does not require damaging high temperature cycles, in several embodiments.

[0043] Some embodiments of the invention may be implemented such that the metal oxide coatings are formed on components of a system prior to its assembly, for example, to a pipe or heat exchanger at its place of original manufacture. In this manner, bulk coatings of metal oxides may be formed in a more automated fashion in those embodiments, thereby providing coverage over the majority of the exterior of a system while still providing a reduced but chosen level of protection against surface corrosion, i.e., leaving the in-field welded areas uncoated, which may be suitable for some applications. In other embodiments, only certain surfaces of a system may be coated for desired performance, whether it is for surface protection against corrosion, biofouling, or other purposes.

[0044] Accordingly, further embodiments of the present invention provide articles of manufacture adaptable to provide an external surface of a system, or a component thereof, wherein the surface comprises at least one metal oxide. In some of those embodiments, at least some of the at least one metal oxide is present as an infused coating. Similarly, still further embodiments provide articles of manufacture adaptable to provide a surface subject to particulate erosion, wherein the surface comprises at least one metal oxide. [0045] Some embodiments of this invention provide a process for applying a surface treatment to an exterior surface of a system or a component thereof such that corrosion, biofouling, or a combination thereof is satisfactorily resisted by the surface treatment and the underlying surface, resulting in improved performance of the system or component thereof. [0046] Other embodiments of the invention provide a method of forming a metal oxide coating that is well-adhered to chosen exterior surfaces of a system, or to a surface subject to particulate erosion. [0047] Still other embodiments of the invention provide a method of forming a metal oxide coating on an exterior surface of a system, or on a surface subject to particulate erosion, wherein the coating has a thickness of about 5 microns or less.

[0048] Additional embodiments of the invention provide a means to economically form a metal oxide coating on chosen exterior surfaces of a system, or on a surface subject to particulate erosion.

[0049] Yet other embodiments provide a method of forming a metal oxide coating on at least one component of a system prior to assembly.

[0050] Further embodiments provide a method of forming a metal oxide coating on at least one component of a system that has been in service, wherein the external surfaces of the component, for example, a pipe or tube, have been cleaned using any suitable method of cleaning exterior surfaces of industrial process system components such as solvent washing, blasting, etching, mechanical and/or chemical polishing, spalling, steam cleaning, and similar methods.

[0051] Other additional embodiments provide a method of forming a metal oxide coating on at least one exterior portion of an assembled system after all assembly welding, brazing, and similar joining processes are completed, when so desired, to eliminate the degradation that occurs when components with pre-existing coatings are joined with high temperature joining processes. For example, creating a welded joint on a bridge with a conventional surface treatment typically results in the degradation of the conventional surface treatment in zones adjoining the welded area, greatly reducing or eliminating the effectiveness of the conventional surface treatment.

[0052] Other embodiments of the invention provide a method of forming multiple layers of at least one metal oxide on at least one portion of a system. In certain embodiments, the process of applying and converting can be repeated, forming at least one metal oxide in more than one layer. Some of those embodiments provide 2, 3, 4, 5, or 6 layers of one or more metal oxides. In still other embodiments, various methods can be used to apply at least one metal compound to the exterior surface, again forming at least one metal oxide in more than one layer. Accordingly, in certain embodiments, this invention relates to processes of applying a chosen composition to chosen exterior surfaces of a system, then utilizing a conversion method to convert the formulation to a useful surface coating.

[0053] In some embodiments of methods of the present invention, at least one metal oxide or metal oxide coating is formed in an inert environment, including an environment wherein no or substantially no oxygen is present. In other embodiments, at least one metal oxide or metal oxide coating is formed in an aerobic environment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Further aspects, features and advantages of the present invention will become apparent from the drawings and detailed description of the embodiments that follow.

[0055] Figure 1 shows a photograph of an uncoated steel coupon after a one hour exposure to Aqua Regia.

[0056] Figure 2 shows a photograph of a steel coupon coated with "Zircon" after one hour exposed to Aqua Regia.

[0057] Figure 3 shows a photograph of a steel coupon coated with "Glass" after one hour exposed to Aqua Regia.

[0058] Figure 4 shows a photograph of a steel coupon coated with "YSZ" after one hour exposed to Aqua Regia.

[0059] Figure 5 shows a photograph of a steel coupon coated with "Clay" after one hour exposed to Aqua Regia.

[0060] Figure 6 shows TEM micrograph at about two million x magnification of a steel substrate having a Y/Zr oxide coating in cross-section.

DETAILED DESCRIPTION

[0061] As used herein, the term "rare earth metal" includes those metals in the lanthanide series of the Periodic Table, including lanthanum. The term "transition metal" includes metals in Groups 3- 12 of the Periodic Table (but excludes rare earth metals). The term "metal oxide" particularly as used in conjunction with the above terms includes any oxide that can form or be prepared from the metal, irrespective of whether it is naturally occurring or not. The "metal" atoms of the metal oxides of the present invention are not necessarily limited to those elements that readily form metallic phases in the pure form. "Metal compounds" include substances such as molecules comprising at least one metal atom and at least one oxygen atom. Metal compounds can be converted into metal oxides by exposure to a suitable environment for a suitable amount of time. [0062] As used herein, the term "phase deposition" includes any coating process onto a substrate that is subsequently followed by the exposure of the substrate and/or the coating material to an environment that causes a phase change in either the coating material, one or more components of the coating material, or of the substrate itself. A phase change may be a physical phase change, such as for example, a change from fluid to solid, or from one crystal phase to another, or from amorphous to crystalline or vice versa. "Adaptable to provide" indicates the ability to make available. For example, an "article adaptable to provide an external surface of a fluid processing or transport system" is an article, such as a pipe, that has a surface that is or can be assembled into such a system by using manufacturing, construction, and/or assembly steps.

[0063] In other embodiments of the invention an inert gas may be provided after the system or component thereof has been wetted with the metal compound composition but prior to heating of even a portion of the system or component. The inert gas, in some embodiments, controls oxidation of the wetted surfaces as their temperature is increased. [0064] In some embodiments of the invention, a liquid composition comprising at least one metal compound may be applied to the outer surface of a system or component thereof, or on a surface subject to particulate erosion, and then the wetted surface is exposed to an environment that will convert at least some of the compound to at least one metal oxide, for example, through the elevation of the temperature of the wetted surface to a desired temperature through known means. The liquid composition can be made more or less viscous as desired, for example, by using more or less solvent, or by adding more or less carboxylic acid in those cases where the at least one metal compound includes one or more metal carboxylates. Similarly, thicker or thinner applications can be made in some embodiments, by applying more or less of the composition to the surface. [0065] The term alkyl, as used herein, refers to a saturated straight, branched, or cyclic hydrocarbon, or a combination thereof, including C| to C₂₄, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, cyclopentyl, isopentyl, neopentyl, n-hexyl, isohexyl, cyclohexyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, heptyl, octyl, nonyl, and decyl.

[0066] The term alkoxy, as used herein, refers to a saturated straight, branched, or cyclic hydrocarbon, or a combination thereof, including Ci to C₂₄, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, cyclopentyl, isopentyl, neopentyl, n-hexyl, isohexyl, cyclohexyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, heptyl, octyl, nonyl, and decyl, in which the hydrocarbon contains a single-bonded oxygen atom that can bond to or is bonded to another atom or molecule. [0067] The terms alkenyl and alkynyl, as used herein, refer to straight, branched, or cyclic hydrocarbon with at least one double or triple bond, respectively, including but not limited to C₂ to C₂₄ hydrocarbons.

[0068] The term aryl or aromatic, as used herein, refers to monocyclic or bicyclic hydrocarbon ring molecule having conjugated double bonds about the ring. In some embodiments, the ring molecule has 5- to 12-members, but is not limited thereto. The ring may be unsubstituted or substituted having one or more alike or different independently- chosen substituents, wherein the substituents are chosen from alkyl, alkenyl, alkynyl, alkoxy, hydroxyl, and amino radicals, and halogen atoms. Aryl includes, for example, unsubstituted or substituted phenyl and unsubstituted or substituted naphthyl.

[0069] The term heteroaryl as used herein refers to a monocyclic or bicyclic aromatic hydrocarbon ring molecule having at least one heteroatom chosen from O, N, P, and S as a member of the ring, and the ring is unsubstituted or substituted with one or more alike or different substituents independently chosen from alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino, thiol, alkylthio, =O, =NH, =PH, =S, and halogen atoms. In some embodiments, the ring molecule has 5- to 12-members, but is not limited thereto. [0070] The term hydrocarbon refers to molecules that contain carbon and hydrogen.

[0071] "Alike or. different," when describing three or more substituents for example, indicates combinations in which (a) all substituents are alike, (b) all substituents are different, and (c) some substituents are alike but different from other substituents. [0072] Suitable metal compounds that form metal oxides include substances such as molecules containing at least one metal atom and at least one oxygen atom. In some embodiments, metal compounds that form metal oxides include metal carboxylates, metal alkoxides, and metal β-diketonates.

A. METAL CARBOXYLATES

[0073] The metal salts of carboxylic acids useful in the present invention can be made from any suitable carboxylic acids according to methods known in the art. For example, U.S. Patent No. 5,952,769 to Budaragin discloses suitable carboxylic acids and methods of making metal salts of carboxylic acids, among other places, at columns 5-6. The disclosure of U.S. Patent No. 5,952,769 is incorporated herein by reference. In some embodiments, the metal carboxylate can be chosen from metal salts of 2-hexanoic acid. Moreover, suitable metal carboxylates can be purchased from chemical supply companies. For example, cerium(III) 2-ethylhexanoate, magnesium(II) stearate, manganese(II) cyclohexanebutyrate, and zinc(II) methacrylate are available from Sigma-Aldrich of St. Louis, MO. See Aldrich Catalogue, 2005-2006. Additional metal carboxylates are available from, for example, Alfa- Aesar of Ward Hill, MA.

[0074] The metal carboxylate composition, in some embodiments of the present invention, comprises one or more metal salts of one or more carboxylic acids ("metal carboxylate"). Metal carboxylates suitable for use in the present invention include at least one metal atom and at least one carboxylate radical -OC(O)R bonded to the at least one metal atom. As stated above, metal carboxylates can be produced by a variety of methods known to one skilled in the art. Non-limiting examples of methods for producing the metal carboxylate are shown in the following reaction schemes: nRCOOH + Me → (RCOO)_nMe⁰⁺ + 0.5nH₂ (for alkaline earth metals, alkali metals, and thallium). nRCOOH + Me⁰⁺(OH)_n → (RCOO)_nMe⁰⁺ + nH₂O (for practically all metals having a solid hydroxide). nRCOOH + Me⁰⁺(CO₃)O 5_n → (RCOO)_nMe⁰⁺ + 0.5nH₂O + 0.5nCO₂ (for alkaline earth metals, alkali metals, and thallium). nRCOOH + Me⁰⁺(XV_m → (RCOO)_nMe⁰⁺ + n/mH_mX (liquid extraction, usable for practically all metals having solid salts).

In the foregoing reaction schemes, X is an anion having a negative charge m, such as, e.g., halide anion, sulfate anion, carbonate anion, phosphate anion, among others; n is a positive integer; and Me represents a metal atom.

[0075] R in the foregoing reaction schemes can be chosen from a wide variety of radicals. Suitable carboxylic acids for use in making metal carboxylates include, for example:

Monocarboxylic acids:

[0076] Monocarboxylic acids where R is hydrogen or unbranched hydrocarbon radical, such as, for example, HCOOH - formic, CH₃COOH - acetic, CH₃CH₂COOH - propionic, CH₃CH₂CH₂COOH (C₄H₈O₂)- butyric, C₅Hi₀O₂ - valeric, C₆Hi₂O₂ - caproic, C7Hi4 - enanthic; further: caprylic, pelargonic, undecanoic, dodecanoic, tridecylic, myristic, pentadecylic, palmitic, margaric, stearic, and nonadecylic acids;

[0077] Monocarboxylic acids where R is a branched hydrocarbon radical, such as, for example, (CH₃)₂CHCOOH - isobutyric, (CH₃) ₂CHCH₂COOH - 3-methylbutanoic, (CH₃)₃CCOOH - trimethylacetic, including VERSATIC 10 (trade name) which is a mixture of synthetic, saturated carboxylic acid isomers, derived from a highly-branched Ci₀ structure; [0078] Monocarboxylic acids in which R is a branched or unbranched hydrocarbon radical containing one or more double bonds, such as, for example, CH₂=CHCOOH - acrylic,

CH₃CH=CHCOOH - crotonic, CH₃(CH₂)₇CH=CH(CH₂)₇COOH - oleic,

CH₃CH=CHCH=CHCOOH - hexa-2,4-dienoic, (CH₃)₂C=CHCH₂CH₂C(CH₃)=CHCOOH -

3,7-dimethylocta-2,6-dienoic, CH₃(CH₂)₄CH=CHCH₂CH=CH(CH₂)₇COOH - linoleic, further: angelic, tiglic, and elaidic acids;

[0079] Monocarboxylic acids in which R is a branched or unbranched hydrocarbon radical containing one or more triple bonds, such as, for example, CH≡CCOOH - propiolic,

CH₃C≡CCOOH - tetrolic, CH₃(CH₂)₄C≡CCOOH - oct-2-ynoic, and stearolic acids;

[0080] Monocarboxylic acids in which R is a branched or unbranched hydrocarbon radical containing one or more double bonds and one or more triple bonds;

[0081] Monocarboxylic acids in which R is a branched or unbranched hydrocarbon radical containing one or more double bonds and one or more triple bonds and one or more aryl groups;

[0082] Monohydroxymonocarboxylic acids in which R is a branched or unbranched hydrocarbon radical that contains one hydroxyl substituent, such as, for example,

HOCH₂COOH - glycolic, CH₃CHOHCOOH - lactic, C₆H₅CHOHCOOH - amygdalic, and

2-hydroxybutyric acids;

[0083] Dihydroxymonocarboxylic acids in which R is a branched or unbranched hydrocarbon radical that contains two hydroxyl substituents, such as, for example,

(HO)₂CHCOOH - 2,2-dihydroxyacetic acid;

[0084] Dioxycarboxylic acids, in which R is a branched or unbranched hydrocarbon radical that contains two oxygen atoms each bonded to two adjacent carbon atoms, such as, for example, C₆H₃(OH)₂COOH - dihydroxy benzoic, C₆H₂(CH₃)(OH)₂COOH - orsellinic; further: caffeic, and piperic acids;

[0085] Aldehyde-carboxylic acids in which R is a branched or unbranched hydrocarbon radical that contains one aldehyde group, such as, for example, CHOCOOH - glyoxalic acid;

[0086] Keto-carboxylic acids in which R is a branched or unbranched hydrocarbon radical that contains one ketone group, such as, for example, CH₃COCOOH - pyruvic,

CH₃COCH₂COOH - acetoacetic, and CH₃COCH₂CH₂COOH - levulinic acids;

[0087] Monoaromatic carboxylic acids, in which R is a branched or unbranched hydrocarbon radical that contains one aryl substituent, such as, for example, C₆HsCOOH - benzoic, C₆H₅CH₂COOH - phenylacetic, C₆H₅CH(CH₃)COOH - 2-phenylpropanoic, C₆H₅CH=CHCOOH - 3-phenylacrylic, and C₆H₅C=CCOOH - 3-phenyl- propiolic acids;

Multicarboxylic acids:

[0088] Saturated dicarboxylic acids, in which R is a branched or unbranched saturated hydrocarbon radical that contains one carboxylic acid group, such as, for example, HOOC-

COOH - oxalic, HOOC-CH₂-COOH - malonic,

HOOC-(CH₂)₂-COOH - succinic, HOOC-(CH₂)₃-COOH - glutaric,

HOOC-(CH₂)₄-COOH - adipic; further: pimelic, suberic, azelaic, and sebacic acids;

[0089] Unsaturated dicarboxylic acids, in which R is a branched or unbranched hydrocarbon radical that contains one carboxylic acid group and at least one carbon-carbon multiple bond, such as, for example, HOOC-CH=CH-COOH - fumaric; further: maleic, citraconic, mesaconic, and itaconic acids;

[0090] Polybasic aromatic carboxylic acids, in which R is a branched or unbranched hydrocarbon radical that contains at least one aryl group and at least one carboxylic acid group, such as, for example, C₆H₄(COOH)₂ - phthalic (isophthalic, terephthalic), and

C₆H₃(COOH)₃ - benzyl-tri-carboxylic acids;

[0091] Polybasic saturated carboxylic acids, in which R is a branched or unbranched hydrocarbon radical that contains at least one carboxylic acid group, such as, for example, ethylene diamine N,N'-diacetic acid, and ethylene diamine tetraacetic acid (EDTA);

Polybasic oxyacids:

[0092] Polybasic oxyacids, in which R is a branched or unbranched hydrocarbon radical containing at least one hydroxyl substituent and at least one carboxylic acid group, such as, for example, HOOC-CHOH-COOH - tartronic,

HOOC-CHOH-CH₂-COOH - malic, HOOC-C(OH)=CH-COOH - oxaloacetic, HOOC-

CHOH-CHOH-COOH - tartaric, and

HOOC-CH₂-C(OH) COOH-CH₂COOH - citric acids.

[0093] In some embodiments, the monocarboxylic acid comprises one or more carboxylic acids having the formula I below:

R°-C(R")(R')~COOH (I) wherein:

R° is selected from H or Ci to C₂₄ alkyl groups; and

R' and R" are each independently selected from H and Q to C₂₄ alkyl groups; wherein the alkyl groups of R°, R', and R" are optionally and independently substituted with one or more substituents, which are alike or different, chosen from hydroxy, alkoxy, amino, and aryl radicals, and halogen atoms.

[0094] Some suitable alpha branched carboxylic acids typically have an average molecular weight in the range 130 to 420. In some embodiments, the carboxylic acids have an average molecular weight in the range 220 to 270. The carboxylic acid may also be a mixture of tertiary and quaternary carboxylic acids of formula I. VIK acids can be used as well. See U.S. Patent No. 5,952,769, at col. 6, 11. 12-51.

[0095] In some embodiments, one or more metal carboxylates can be synthesized by contacting at least one metal halide with at least one carboxylic acid in the substantial absence of water. In other embodiments, the contacting occurs in the substantial absence of a carboxylic anhydride, yet in specific embodiments at least one carboxylic anhydride is present. In still other embodiments, the contacting occurs in the substantial absence of a catalyst; however, particular embodiments provide at least one catalyst. For example, silicon tetrachloride, aluminum trichloride, titanium tetrachloride, titanium tetrabromide, or a combination of two or more thereof can be mixed into 2-ethylhexanoic acid, glacial acetic acid, or another carboxylic acid or a combination thereof in the substantial absence of water with stirring to produce the corresponding metal carboxylate or combination thereof. Carboxylic anhydrides and/or catalysts can be excluded, or are optionally present. In some embodiments, the carboxylic acid is present in excess. In other embodiments, the carboxylic acid is present in a stoichiometric ratio to the at least one metal halide. Certain embodiments provide the at least one carboxylic acid in a stoichiometric ratio with the at least one metal halide of about 1 :1, about 2: 1 , about 3: 1 , or about 4: 1. The contacting of the at least one metal halide with at least one carboxylic acid can occur under any suitable conditions. For example, the contacting optionally can be accompanied by heating, partial vacuum, and the like.

[0096] Either a single carboxylic acid or a mixture of carboxylic acids can be used to form the metal carboxylate composition. In some embodiments, a mixture of carboxylic acids is used. In still other embodiments, the mixture contains 2-ethylhexanoic acid where R° is H, R" is C₂H₅ and R' is C4H₉ in formula (I) above. In some embodiments, this acid is the lowest boiling acid constituent in the mixture. When a mixture of metal carboxylates is used, the mixture has a broader evaporation temperature range, making it more likely that the evaporation temperature of the mixture will overlap the metal carboxylate decomposition temperature, allowing the formation of a solid metal oxide coating. Moreover, the possibility of using a mixture of carboxylates avoids the need and expense of purifying an individual carboxylic acid.

B. METAL ALKOXTOES

[0097] Metal alkoxides suitable for use in the present invention include at least one metal atom and at least one alkoxide radical -OR² bonded to the at least one metal atom. Such metal alkoxides include those of formula II:

M(OR²)₂ (II) in which M is a metal atom of valence z+; z is a positive integer, such as, for example, 1, 2, 3, 4, 5, 6, 7, and 8;

R² can be alike or different and are independently chosen from unsubstituted and substituted alkyl, unsubstituted and substituted alkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroaryl, and unsubstituted and substituted aryl radicals, wherein substituted alkyl, alkenyl, alkynyl, heteroaryl, and aryl radicals are substituted with one or more alike or different substituents independently chosen from halogen, hydroxy, alkoxy, amino, heteroaryl, and aryl radicals.

In some embodiments, z is chosen from 2, 3, and 4.

[0098] Metal alkoxides are available from Alfa-Aesar and Gelest, Inc., of Morrisville,

PA. Lanthanoid alkoxides such as those of Ce, Nd, Eu, Dy, and Er are sold by Kojundo Chemical Co., Saitama, Japan, as well as alkoxides of Al, Zr, and Hf, among others. See, e.g., http://www.kojundo.co.jp/English/Guide/material/lanthagen.html. [0099] Examples of metal alkoxides useful in embodiments of the present invention include methoxides, ethoxides, propoxides, isopropoxides, and butoxides and isomers thereof. The alkoxide substituents on a give metal atom are the same or different. Thus, for example, metal dimethoxide diethoxide, metal methoxide diisopropoxide t-butoxide, and similar metal alkoxides can be used. Suitable alkoxide substituents also may be chosen from:

1. Aliphatic series alcohols from methyl to dodecyl including branched and isostructured.

2. Aromatic series alcohols: benzyl alcohol - C₆H₅CH₂OH; phenyl-ethyl alcohol - C₈HιoO; phenyl- propyl alcohol - CgHi₂O, and so on.

[00100] Metal alkoxides useful in the present invention can be made according to many methods known in the art. One method includes converting the metal halide to the metal alkoxide in the presence of the alcohol and its corresponding base. For example:

MX_z + zH0R² → M(OR²)_z + zHX in which M, R², and z are as defined above for formula II, and X is a halide anion.

C. METAL β-DIKETONATES

[00101] Metal β-diketonates suitable for use in the present invention contain at least one metal atom and at least one β-diketone of formula III as a ligand:

in which

R³, R⁴, R⁵, and R⁶ are alike or different, and are independently chosen from hydrogen, unsubstituted and substituted alkyl, unsubstituted and substituted alkoxy, unsubstituted and substituted alkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroaryl, unsubstituted and substituted aryl, carboxylic acid groups, ester groups having unsubstituted and substituted alkyl, and combinations thereof, wherein substituted alkyl, alkoxy, alkenyl, alkynyl, heteroaryl, and aryl radicals are substituted with one or more alike or different substituents independently chosen from halogen atoms, hydroxy, alkoxy, amino, heteroaryl, and aryl radicals. [00102] It is understood that the β-diketone of formula III may assume different isomeric and electronic configurations before and while chelated to the metal atom. For example, the free β-diketone may exhibit enolate isomerism. Also, the β-diketone may not retain strict carbon-oxygen double bonds when the molecule is bound to the metal atom. [00103] Examples of β-di ketones useful in embodiments of the present invention include acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, 2,2,6,6-tetramethyl- 3,5-heptanedione, 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione, ethyl acetoacetate, 2-methoxyethyl acetoacetate , benzoyltrifluoroacetone, pivaloyltrifluoroacetone, benzoyl- pyruvic acid, and methyl-2,4-dioxo-4-phenylbutanoate.

[00104] Other ligands are possible on the metal β-diketonates useful in the present invention, such as, for example, alkoxides such as -OR² as defined above, and dienyl radicals such as, for example, 1 ,5-cyclooctadiene and norbornadiene.

[00105] Metal β-diketonates useful in the present invention can be made according to any method known in the art. β-diketones are well known as chelating agents for metals, facilitating synthesis of the diketonate from readily available metal salts. [00106] Metal β-diketonates are available from Alfa-Aesar and Gelest, Inc. Also, Strem Chemicals, Inc. of Newburyport, MA, sells a wide variety of metal β-diketonates on the internet at http://www.strem.com/code/template.ghc?direct=cvdindex. [00107] In some embodiments, the method of the invention can include a pre- application cleaning step prior to the application of the composition. In these embodiments, the invention involves the application of one or more cleaning materials, which may be in vapor, liquid, semi-solid phase, or a combination of these to at least a portion of the surfaces of the final system, followed by a flushing and drying cycle at a drying temperature. The cleaning technique can be of the type used for cleaning surfaces prior to coating, plating, painting, or similar surface treatments. The pre-application cleaning step may also include a pickling operation using known chemicals and process in order to prepare the surface(s) for coating.

[00108] The surface to be treated according to the invention also can be pretreated, in further embodiments, before the application of the composition. In some cases, the surface can be etched according to known methods, for example, with an acid wash comprising nitric acid, sulphuric acid, hydrochloric acid, phosphoric acid, or a combination of two or more thereof, or with a base wash comprising sodium hydroxide or potassium hydroxide, for example. In further cases, the surface can be mechanically machined or polished, with or without the aid of one or more chemical etching agents, abrasives, and polishing agents, to make the surface either rougher or smoother. In some embodiments, no pretreatment is used, and the at least one metal compound is applied to the surface as the surface was manufactured. In other embodiments, 600 grit or finer abrasive is used to polish the surface before applying the at least one metal compound. Shot blasting is employed for certain embodiments. Dry ice can be used in some instances, to remove surface oxidation and scaling before applying the at least one metal compound. In still further cases, the surface can be pretreated such as by carburizing, nitriding, painting, powder coating, plating, or anodizing. Thin films of chrome, tin, and other elements, alone or in combination, can be deposited, in some embodiments. Methods for depositing thin films are well known and include chemical vapor deposition, physical vapor deposition, molecular beam epitaxy, plasma spraying, electroplating, ion impregnation, and others.

[00109] In some embodiments of the present invention, a metal compound comprises a transition metal atom. In other embodiments, a metal compound comprises a rare earth metal atom. In further embodiments, the metal compound composition comprises a plurality of metal compounds. In some embodiments, a plurality of metal compounds comprises at least one rare earth metal compound and at least one transition metal compound, while in other embodiments, a plurality of metal compounds comprises other than at least one rare earth metal compound and at least one transition metal compound. Metal carboxylates, metal alkoxides, and metal β-diketonates can be chosen for some embodiments of the present invention.

[00110] In further embodiments, a metal compound mixture comprises one metal compound as its major component and one or more additional metal compounds which may function as stabilizing additives. Stabilizing additives, in some embodiments, comprise trivalent metal compounds. Trivalent metal compounds include, but are not limited to, chromium, iron, manganese, and nickel compounds. A metal compound composition, in some embodiments, comprises both cerium and chromium compounds. [00111] In some embodiments, the metal compound that is the major component of the metal compound composition contains an amount of metal that ranges from about 65 to about 97% by weight or from about 80 to about 87% by weight of the total weight of metal in the composition. In other embodiments, the amount of metal forming the major component of the metal compound composition ranges from about 90 to about 97% by weight of the total metal present in the composition. In still other embodiments, the amount of metal forming the major component of the metal compound composition ranges from about 97 to about 100% by weight of the total metal present in the composition.

[00112] The metal compounds that may function as stabilizing additives, in some embodiments, may be present in amounts such that the total amount of the metal in metal compounds which are the stabilizing additives is at least 3% by weight, relative to the total weight of the metal in the metal compound composition. This can be achieved in some embodiments by using a single stabilizing additive, or multiple stabilizing additives, provided that the total weight of the metal in the stabilizing additives is greater than 3%. In other embodiments, the amount of the stabilizing metal is less than 3 % relative to the total weight of metal in the metal compound composition. In yet other embodiments, the total weight of the metal in the stabilizing additives ranges from about 3% to about 35% by weight. In still other embodiments, the total weight for the metal in the stabilizing additives ranges from about 3 to about 30% by weight, relative to the total weight of the metal in the metal compound composition. In other embodiments, the total weight range for the metal in the stabilizing additives ranges from about 3 to about 10% by weight. In some embodiments, the total weight range for the metal in the stabilizing additives is from about 7 to about 8% by weight, relative to the total weight of the metal in the metal compound composition. Still other embodiments provide the stabilizing metal in an amount greater than about 35 % by weight relative to the total weight of the metal in the metal compound composition. [00113] The amount of metal in the metal compound composition, according to some embodiments, ranges from about 20 to about 150 grams of metal per kilogram of metal compound composition. In other embodiments, the amount of metal in the metal compound composition ranges from about 30 to about 50 grams of metal per kilogram of metal compound composition. In further embodiments, the metal compound composition can contain from about 30 to about 40 grams of metal per kg of composition. Amounts of metal less than 20 grams of metal per kilogram of metal compound composition or greater than about 150 grams of metal per kilogram of metal compound composition also can be used. [00114] The metal compound may be present in any suitable composition. Finely divided powder, nanoparticles, solution, suspension, multi-phase composition, gel, vapor, aerosol, and paste, among others, are possible.

[00115] The metal compound composition may also include nanoparticles in the size range of less than 100 nm in average size and being composed of a variety of elements or combination thereof, for example, Al₂O₃, CeO₂, Ce₂O₃, TiO₂, ZrO₂, Ag, and others. In some cases, the nanoparticles can be dispersed, agglomerated, or a mixture of dispersed and agglomerated nanoparticles. Nanoparticles may have a charge applied to them, negative or positive, to aid dispersion. Moreover, dispersion agents, such as known acids or surface modifying agents, may be used. The presence of nanoparticles may decrease the porosity of the final coating; the level of porosity will generally decrease with increasing quantity and decreasing size of the included nanoparticles. Coating porosity can also be influenced by applying additional coating layers according to the process of the invention; porosity will generally decrease with an increasing number of layers. In some embodiments the nanoparticles may be first mixed with a liquid and then mixed with the compound composition; this method provides a means to create a fine dispersion in a first liquid which retains its dispersion when mixed with a second, or third liquid. For example, nanoparticles of chosen elements, oxides, molecules, or alloys may be dispersed into a first liquid and, after a desired quality of dispersion is achieved, the nanoparticles in the first liquid may be mixed with the liquid metal compound composition prior to the exposure of the final composition to an environment that will convert at least a portion of the metal compound(s) into metal oxides. The result may be a more dense film with reduced porous sites. [00116] The applying of the metal compound composition may be accomplished by various processes, including dipping, spraying, flushing, vapor deposition, printing, lithography, rolling, spin coating, brushing, swabbing, or any other means that allows the metal compound composition to contact the desired portions of the surface to be treated. In this regard, the metal compound composition may be liquid, and may also comprise a solvent. The optional solvent may be any hydrocarbon and mixtures thereof. In some embodiments, the solvent can be chosen from carboxylic acids; toluene; benzene; alkanes, such as for example, propane, butane, isobutene, hexane, heptane, octane, and decane; alcohols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol; mineral spirits; β-diketones, such as acetylacetone; ketones such as acetone; high-paraffin, aromatic hydrocarbons; and combinations of two or more of the foregoing. Some embodiments employ solvents that contain no water or water in trace amounts or greater, while other embodiments employ water as a solvent. In some embodiments, the metal compound composition further comprises at least one carboxylic acid. Some embodiments employ no solvent in the metal compound composition. Other embodiments employ no carboxylic acid in the metal compound composition.

[00117] The metal compound composition can applied in some embodiments in which the composition has a temperature less than about 250 ⁰C. That composition also can be applied to the substrate in further embodiments at a temperature less than about 50 ⁰C. In other embodiments, the liquid metal compound composition is applied to the substrate at room temperature. Yet other embodiments provide the composition is applied at a temperature above about 0 ⁰C. In still other embodiments, that composition is applied at a temperature greater than about 250 ⁰C.

[00118] In further embodiments of the invention, wetting of the outer surfaces of a pipe, for example, is followed by a curing phase wherein heat is provided to the surfaces using suitable methods to achieve the conversion of at least a portion of the delivered liquid into a metal oxide coating. As described herein, suitable methods for converting at least a portion of the at least one metal compound into at least one metal oxide include, but are not limited to, flushing the wetted system or component thereof with high-temperature gas; induction heating of the walls of the system or component; heating with one or more lasers, microwave emitters, infrared emitters, or plasma; flaming, for example of the outside walls of the system or component optionally with the aid of one or more heat shields between the flame and the wetted surface, exposing the wetted system or component to the thermal energy of one or more exothermic reactions, and combinations thereof.

[00119] In some embodiments, a feed of an inert gas may be provided to create a non- oxidizing atmosphere for the heating process of the conversion liquid and the material underneath such that oxidation of the outer wall of the component is reduced or eliminated. Alternatively, other embodiments provide a vacuum or partial vacuum. In those embodiments, the vacuum or partial vacuum may be provided by any one of a variety of known vacuum-producing systems including, but not limited to, pumps, blowers, molecular drag systems, turbo-molecular systems, cryosorption processes, sputter-ion pump, and similar devices.

[00120] Following application, the at least one metal compound is at least partially converted to at least one metal oxide. In some embodiments the at least one metal compound is fully converted to at least one metal oxide.

[00121] Suitable environments for converting the at least one metal compound into at least one metal oxide are not limited, and include vacuum, partial vacuum, atmospheric pressure, high pressure equal to several atmospheres, high pressure equal to several hundred atmospheres, inert gases, and reactive gases such as gases comprising oxygen, including pure oxygen, air, dry air, and mixtures of oxygen in various ratios with one or more other gases such as nitrogen, carbon dioxide, helium, neon, and argon, as well as hydrogen, mixtures of hydrogen in various ratios with one or more other gases such as nitrogen, carbon dioxide, helium, neon, and argon, also other gases such as, for example, steam, nitrogen, NH₃, hydrocarbons, H₂S, PH₃, each alone or in combination with various gases, and still other gases which may or may not be inert in the converting environment. In some embodiments, a suitable environment for converting the at least one metal compound into at least one metal oxide is free or substantially free of oxygen.

[00122] The environment may be heated relative to ambient conditions, in some embodiments. In other embodiments, the environment may comprise reactive species that cause or catalyze the conversion of the metal compound to the metal oxide, such as, for example, acid-catalyzed hydrolysis of metal alkoxides. In still other embodiments, the metal compound is caused to convert to the metal oxide by the use of induction heating, lasers, microwave emission, or plasma, as explained herein.

[00123] The conversion environment may be accomplished in a number of ways. For example, a conventional oven may be used to bring the surface having the at least one metal compound up to a temperature exceeding approximately 250⁰C for a given period of time. In some embodiments, the environment of the coated substrate is heated to a temperature exceeding about 400⁰C but less than about 45O⁰C or less than about 500⁰C for a chosen period of time. In other embodiments, the environment of the coated substrate is heated to a temperature ranging from about 400⁰C to about 650⁰C. In further embodiments, the environment is heated to a temperature ranging from about 45O⁰C to about 55O⁰C. In still further embodiments, the environment is heated to a temperature ranging from about 550⁰C to about 650 ⁰C, from about 650⁰C to about 800⁰C, or from about 800 ⁰C to about 1000⁰C. In one embodiment, the environment is heated to a temperature of up to about 425⁰C or about 45O⁰C. In another embodiment, the environment is heated to a temperature of less than about 425⁰C or less than about 45O⁰C. Depending on the size of the components and/or process equipment, pipes, etc., the time period may be extended such that sufficient conversion of a desired amount of the metal compound to metal oxides has been accomplished. [00124] The rate at which the environment is heated to effect the conversion of the at least one metal compound to the at least one metal oxide is not limited. In some embodiments, the heating rate is less than about 7 °C/minute. In other embodiments, the heating rate is equal to about 7 °C/minute. In still other embodiments, the heating rate is greater than about 7 ⁰C/ minute. The heating rate, according to certain iterations of the present invention, is equal to the heating rate of the oven in which the conversion takes place. Particular embodiments provide a heating rate that is as fast as the conditions and equipment allow.

[00125] In some applications, the oxidation of the surface being treated is not desired.

In these cases, an inert atmosphere may be provided in the conversion environment to prevent such oxidation. In the case of heating the component in a conventional oven, a nitrogen or argon atmosphere can be used, among other inert gases, to prevent or reduce the oxidation of the surface prior to or during the conversion process. Alternatively, or in combination in a multi-step process, vacuum or partial vacuum can be used to create a non-oxidizing atmosphere. Thus, some embodiments provide converting the at least one metal compound to at least one metal oxide in a non-oxidizing atmosphere.

[00126] The conversion environment may also be created using induction heating through means familiar to those skilled in the art of induction heating. For example, an induction wand can be passed proximate to a surface containing the at least one metal oxide, wherein the surface is susceptible to induction heating. In some cases, an electrically- conductive surface is susceptible to induction heating. In other cases, a surface comprising electrically-conductive particles is susceptible to induction heating. As the induction wand moves past the surface, the wand inductively heats the surface and the at least one metal compound is converted into at least one metal oxide. Certain embodiments provide the use of one or more induction collars. An induction collar can be fashioned around an article, for example, having a high aspect ratio as a pipe section, a rod, or an I-beam. The at least one metal compound on the surface can be converted into at least one metal oxide by the heat generated in the article by the induction collar passing down the length of the article. The article can be fully assembled into the system, or the article can be treated with the induction collar at the site of manufacture of the article or at another site. In some embodiments, articles to be treated can be taken off-site and one or more induction heaters, furnaces, other heating implements, and combinations thereof can cause the conversion of the metal compound into the metal oxide.

[00127] Alternatively, the conversion environment may be provided using a laser applied to the surface area for sufficient time to allow at least some of the metal compounds to convert to metal oxides. In other applications, the conversion environment may be created using an infra-red light source which can reach sufficient temperatures to convert at least some of the metal compounds to metal oxides. Some embodiments may employ a microwave emission device to cause at least some of the metal compound to convert. Still other embodiments employ a plasma to provide the environment for converting the metal compound into metal oxide. In the case of induction heating, microwave heating, lasers, plasmas, and other heating methods that can produce the necessary heat levels in a short time, for example, within seconds, 1 minute, 10 minutes, 20 minutes, 30 minutes, 40 minutes, or one hour. Accordingly, in some embodiments, the conversion environment can be created without the use of an inert gaseous environment, thus enabling conversion to be done in open air, outside of a closed system due to the reduced time for undesirable compounds to develop on the material's surface in the presence of ambient air.

[00128] The gas above the metal compound on the surface can be heated, in some embodiments, to convert the metal compound to the metal oxide. In other embodiments, heating can be accomplished by introducing high temperature process gases, which are fed through the assembled system and thereby heat the exterior upon which the metal compound has been applied, wherein the exterior surfaces of the fluid transport or processing system become covered with a protective thin film of the desired metal oxide(s). This high temperature gas can be produced by a conventional oven, induction heating coils, heat exchangers, industrial process furnaces, exothermic reactions, microwave emission, or other suitable heating method. Process gases can be chosen from, but are not limited to, nitrogen, argon, steam, oxygen, air, dry air, other reactive gases, other inert gases, and combinations thereof. [00129] Areas that are to be kept free of the coating of the invention can be masked-off using known means prior to the application of the method's composition and its conversion using some heat or energy source.

[00130] In other applications, the metal compound composition may be applied to chosen areas of a component or system and an induction heating element may be passed proximate to the area of interest to create the conversion environment. In some applications, the wetted surface of a component may not be visible by line of sight, but an induction wand held proximate to the inside or outside surfaces of the component may allow sufficient heat to be developed on the wetted surfaces being treated with the metal compounds such that the desired oxides are formed by an indirect heating method. This technique would also be possible using infra-red heating from inside or outside of a component, flame heating, or other known heating methods wherein the material of the component can be raised to the desired temperature to ensure the conversion of the metal compounds to oxides. Using this method of indirect heating may also be used with a chosen atmosphere that may be provided proximate to the wetted surfaces of the pipe or component, such as an inert atmosphere made up of argon, as one example, which would serve to prevent undesirable oxides to form on the material surface being treated.

[00131] Some embodiments of the present invention provide a metal oxide coating on a surface that is subject to corrosion, for example, from the elements, thermal energy, and/or process effluent. Other embodiments provide a metal oxide coating on a surface that is subject to corrosive attack by one or more species present in the process stream. Still other embodiments provide a metal oxide coating on a surface that is subject to particulate erosion. The skilled artisan will appreciate that more than one mechanism can operate to degrade the same surface. Accordingly, the foregoing embodiments do not suggest exclusive mechanisms for any given surface.

[00132] Industrial fluid processing and/or transport systems operable to be treated with metal oxides including metal oxide coatings, according to some embodiments of the invention, include without limitation petroleum refineries, petrochemical processing plants, petroleum transport and storage facilities such as pipelines, oil tankers, fuel transport vehicles, and gas station fuel tanks and pumps, industrial chemical manufacturing plants, aeronautical and aerospace fluid storage and transport systems including fuel systems and hydraulic systems, food and dairy processing systems, combustion engines, turbine engines, and rocket engines. [00133] Some embodiments provide a method for forming at least one metal oxide on a surface subject to a high-temperature environment. The high-temperature environment may relate to manufacture, operation, and/or maintenance of a given system, and is not to be confused with the "high temperature" useful in some embodiments for converting the at least one metal compound into the at least one metal oxide. In some embodiments, the high- temperature environment comprises a temperature greater than about 200 ⁰C, greater than about 300 ⁰C, greater than about 400 °C, greater than about 500 ⁰C, greater than about 600 ⁰C, greater than about 700 ⁰C, greater than about 800 °C, greater than about 900 ⁰C, greater than about 1000 ⁰C, greater than about 1 100 °C, greater than about 1200 ⁰C, greater than about 1300 ⁰C, greater than about 1400 °C, or greater than about 1500 ⁰C. In other embodiments, the high-temperature environment comprises a temperature less than about 250 ⁰C, less than about 350 ⁰C, less than about 450 ⁰C, less than about 550 ⁰C, less than about 600 ⁰C, less than about 650 ⁰C, less than about 750 ⁰C, less than about 850 ⁰C, less than about 950 ⁰C, less than about 1050.⁰C, less than about 1 150 ⁰C, less than about 1250 ⁰C, less than about 1350 ⁰C, less than about 1450 ⁰C, or less than about 1550 ⁰C. Several such metal oxides and combinations thereof can withstand the high-temperature environment. In some cases, withstanding the high-temperature environment means yielding no visible signs of significant cracking or delaminating after one or more exposures to the high-temperature environment. Certain embodiments provide no evidence of cracking or delaminating under 10Ox to 100Ox magnification. In other cases, withstanding the high-temperature environment means that substantially no oxidation of the surface is observed after one or more exposures to the high-temperature environment. In still other cases, withstanding the high-temperature environment means that substantially less oxidation and/or scaling of the surface is observed relative to a surface without the at least one metal oxide after one or more exposures to the high-temperature environment.

[00134] Still other embodiments provide a system comprising at least one surface comprising at least one metal oxide coating, in which the system has a large size. A large size is useful for commercial scale processes. Systems, such as industrial fluid processing or transport systems include, but are not limited to, oil refineries; waste water treatment plants; drinking water treatment plants; cooling water systems such as those found in manufacturing plants and power plants; desalinization plants; and processing systems found in colorants manufacturing, cosmetics manufacturing, food processing, chemical manufacturing, pharmaceutical manufacturing, and the like. [00135] In some embodiments, the exterior surface of the system, or the surface subject to particulate erosion, to receive a metal oxide coating in accordance with the present invention has a surface area greater than about 100 square feet. In other embodiments, the surface area ranges from about 100 square feet to about 500 square feet, from about 500 square feet to about 1,000 square feet, from about 1 ,000 square feet to about 10,000 square feet, from about 10,000 square feet to about 20,000 square feet, from about 20,000 square feet to about 50,000 square feet, from about 50,000 square feet to about 100,000 square feet, from about 100,000 square feet to about 1,000,000 square feet, from about 1,000,000 square feet to about 10,000,000 square feet, from about 10,000,000 square feet to about 1 square mile, from about 1 square mile to about 5 square miles, from about 5 square miles to about 10 square miles, or greater than about 10 square miles.

[00136] In other applications, multiple coats may be desired such that further protection of the material's surface is provided. To reduce the time between applications of the coating of the invention, cooling methods may be used after each heating cycle to bring the surfaces to the required temperatures prior to subsequent applications of the metal compounds. Such cooling methods may be used that are known to the art such as water spraying, cold vapor purging through the interior of the system, evaporative cooling methods, and others.

[00137] Some embodiments of the present invention provide a metal oxide coating that is more resistant to corrosion, biofouling, or particulate erosion (or a combination thereof) than the uncoated surface, in the manner of armor: the surface has a greater service life because the attacking agent cannot reach the surface. In other embodiments, the metal oxide coating protects the surface by providing an ablative layer: the surface has a greater service life because the metal oxide coating sacrificially degrades instead of the surface it protects. Thus, in certain embodiments, organisms cannot attach to the surface because a portion of the coating flakes off once an organism attaches to the coating. In further embodiments, a coated surface lasts longer because the coating is damaged by particle impacts, rather than the surface. It is possible, in still further embodiments, to coat a surface, place the surface in service for a time, and then form additional metal oxide in accordance with the methods described herein to maintain the protection of the surface.

[00138] Representative coating compositions that have been found to be suitable in embodiments of the present invention include, but are not limited to: ZrO₂ for example, at 0-90 wt%

CeO₂ for example, at 0-90 wt% CeO₂-ZrO₂ where CeO₂ is about 10-90 wt%

Y₂O₃ Yttria-stabilized Zirconia where Y is about 1 -50% mol%

TiO₂ for example, at 0-90 wt%

Fe₂O₃ for example, at 0-90 wt%

NiO for example, at 0-90 wt%

Al₂O₃ for example, at 0-90 wt%

SiO₂

Y₂O₃

Cr₂O₃

Mo₂O₃

HfO₂

La₂O₃

Pr₂O₃

Nd₂O₃

Sm₂O₃

Eu₂O₃

Gd₂O₃

Tb₂O₃

Dy₂O₃

Ho₂O₃

Er₂O₃

Tm₂O₃

Yb₂O₃

Lu₂O₃

Mixtures of these compositions are also suitable for use in the invention. [00139] Oxides of the following elements also can be used in embodiments of the present invention: Lithium, Beryllium, Sodium, Magnesium, Aluminum, Silicon, Potassium, Calcium, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Gallium, Germanium, Arsenic, Bromine, Rubidium, Strontium, Yttrium, Zirconium, Niobium, Molybdenum, Technetium, Ruthenium, Rhodium, Palladium, Antimony, Tellurium, Silver, Cadmium, Indium, Tin, Cesium, Barium, Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Hafnium, Tantalum,

Tungsten, Rhenium, Osmium, Iridium, Platinum, Gold, Mercury, Thallium, Lead, Bismuth, Radium, Actinium, Thorium, Protactinium, Uranium, Neptunium, Plutonium, Americium, Curium, Berkelium, Californium, Einsteinium, Fermium, Mendelevium, Nobelium, and Lawrencium. Oxides containing more than one of the foregoing elements, and oxides containing elements in addition to the foregoing elements, also can be used in embodiments of the present invention. For example, SrTiO₃ and MgAl₂O₄ are included. Those materials are likely to form at least in small amounts when appropriate metal compounds are used, depending on the conditions of the conversion process. In some embodiments, the molar ratio of metal compounds deposited on the surface corresponds to the molar ratio of metal oxides after conversion.

[00140] The invention relates, in some embodiments, to infused coatings and thin films (and articles coated therewith) containing at least one rare earth metal oxide, and at least one transition metal oxide. As used herein, "infused" means that metal oxide molecules, nanoparticles, nanocrystals, larger domains, or more than one of the foregoing, have penetrated the substrate. The infusion of metal oxides can range in concentration from rare interstitial inclusions in the substrate, up to the formation of materials that contain significant amounts of metal oxide. A thin film is understood to indicate a layer, no matter how thin, composed substantially of metal oxide. In some embodiments, a thin film has very little or no substrate material present, while in other embodiments, a thin film comprises atoms, molecules, nanoparticles, or larger domains of substrate ingredients. In some embodiments, it may be possible to distinguish between infused portions and thin films. In other embodiments, a gradient may exist in which it becomes difficult to observe a boundary between the infused coating and the thin film. Furthermore, some embodiments may exhibit only one of an infused coating and a thin film. Still other embodiments include thin films in which one or more species have migrated from the substrate into the thin film. The terms "metal oxide coating" and "surface comprises at least one metal oxide" include all of those possibilities, including infused coatings, thin films, stacked thin films, and combinations thereof.

[00141] As explained herein, the infused coating of some embodiments of the invention provides increased performance, in part, because it penetrates the surface of the coated substrate to a depth providing a firm anchor to the material being coated without the need for intermediate bonding layers. In some embodiments, the infused coating penetrates the substrate to a depth of less than about 100 Angstroms. In other embodiments, the infused coating penetrates from about 100 Angstroms to about 200 Angstroms, from about 200

Angstroms to about 400 Angstroms, from about 400 Angstroms to about 600 Angstroms, and greater than about 600 Angstroms, and in some embodiments from about 200 to about 600 Angstroms. This infused coating allows much thinner films [in some embodiments around 0.1 to 1 microns in thickness (or about 0.5 microns when approximately 6 layers are used)] to be applied, and yet may provide equivalent protection to that provided by conventional coating or thin film technologies. This, in turn, allows for thinner films or coatings to be established, reducing significantly the cost of materials attaching to the substrate. Thus, some embodiments of the present invention provide a thin film no thicker than about 5 nm. Other embodiments provide a thin film no thicker than about 10 nm. Still other embodiments provide a thin film no thicker than about 20 nm. Still other embodiments provide a thin film no thicker than about 100 nm. Other embodiments provide a thin film having a thickness less than about 25 microns. Still other embodiments provide a thin film having a thickness less than about 20 microns. Still other embodiments provide a thin film having a thickness less than about 10 microns. Yet other embodiments provide a thin film having a thickness less than about 5 microns. Some embodiments provide a thin film having a thickness less than about 2.5 microns. Even other embodiments provide a thin film having a thickness less than about 1 micron.

[00142] Further embodiments of the present invention provide an article of manufacture having at least one exterior surface comprising at least one metal oxide and an improved thermal conductivity through that surface. In some embodiments, that improved thermal conductivity is improved relative to conventional surface treatments. Additional embodiments provide a thermal conductivity that is improved at least about 0.1 %, at least about 0.5 %, at least about I %, at least about 5 %, at least about IO %, or at least about 15 %, relative to a conventional surface treatment.

[00143] In some embodiments of the invention, the metal oxide coating can contain other species, such as, for example, species that have migrated from the substrate into the metal oxide coating. In other embodiments, those other species can come from the atmosphere in which the at least one metal compound is converted. For example, the conversion can be performed in an environment in which other species are provided via known vapor deposition methods. Still other embodiments provide other species present in or derived from the at least one metal compound or the composition comprising the compound. Suitable other species include metal atoms, metal compounds including those metal atoms, such as oxides, carbides, nitrides, sulfides, phosphides, and mixtures thereof, and the like. The inclusion of other species can be accomplished by controlling the conditions during conversion, such as the use of a chosen atmosphere during the heat conversion process, for example, a partial vacuum or atmosphere containing O₂, N₂, NH₃, one or more hydrocarbons, H₂S, alkylthiols, PH₃, or a combination thereof. [00144] Some embodiments of the present invention provide metal oxide coatings that are substantially free of other species. For example, small amounts of carbides may form along side oxides when, for example, metal carboxylates are converted, if no special measures are taken to eliminate the carbon from the carboxylate ligands. Thus, converting metal compounds in the presence of oxygen gas, air, or oxygen mixed with other gases reduces or eliminates carbide formation in some embodiments of the present invention. Also, rapid heating of the conversion environment, such as, for example, by induction heating, microwave heating, lasers, plasmas, and other heating methods that can produce the necessary heat levels in a short time, reduces or eliminates formation of other species, in other embodiments. At least one rapid heating technique is used in combination with an oxygen-containing atmosphere in still other embodiments.

[00145] Additional embodiments employ various heating steps to reduce or eliminate the formation of other species. For example, carbide formation can be lessened during metal oxide formation in some embodiments by applying a metal compound precursor composition containing a metal carboxylate to a surface, subjecting the surface to a low-temperature bake at about 250 ⁰C under a vacuum, introducing air and maintaining the temperature, and then increasing the temperature to about 420 ⁰C under vacuum or inert atmosphere to convert the metal carboxylate into the metal oxide. Without wanting to be bound by theory, it is believed that the low-temperature bake drives off most or all of the carboxylate ligand, resulting in an oxide film substantially free of metal carbide.

[00146] Still other embodiments employ more than one layer to achieve at least one layer substantially without other species. For example, in some embodiments, a base coat of at least one metal oxide is formed from at least one metal carboxylate under an inert atmosphere. Such a base coat may contain metal carbides due to the initial presence of the carboxylate ligands. Moreover, such a base coat may exhibit good adhesion and strength, for example, when the surface comprises a carbon steel alloy. Then, one or more subsequent metal compounds are repeatedly applied and converted in an oxygen-containing atmosphere, for example, and the subsequent layers of metal oxide form substantially without metal carbides. In some embodiments, six or more layers are formed on the base coat. [00147] In addition, the effect of any mismatches in physical, chemical, or crystallographic properties (particularly with regard to differences in thermal expansion coefficients) may be minimized by the use of much thinner coating materials and the resulting films. Furthermore, the smaller crystallite structure of the film (3-6 nanometers, in some embodiments) increases Hall-Petch strength in the film's structure significantly. [00148] In some embodiments, the present invention provides methods of reducing differences in coefficients of thermal expansion between a substrate and a metal oxide coating proximal to the substrate. In some embodiments, methods of reducing differences in coefficients of thermal expansion between a substrate and at least one metal oxide comprise interposing an infused coating between the substrate and the metal oxide. Interposing such an infused coating comprises applying at least one metal compound to the substrate, and then at least partially converting the at least one metal compound to at least one metal oxide. [00149] The thermal stability of the metal oxide coating can be tested, in some embodiments, by exposing the coated material to thermal shock. For example, a surface having a metal oxide coating can be observed, such as by microscopy. Then the surface can be exposed to a thermal shock, such as by rapid heating or by rapid cooling. Rapid cooling can be caused by, for example, dunking the room-temperature or hotter surface into liquid nitrogen, maintaining the surface under liquid nitrogen for a time, and then removing the surface from the liquid nitrogen. The surface is then observed again, to look for signs that the metal oxide coating is delaminating, cracking, or otherwise degrading because of the thermal shock. The thermal shock test can be repeated to see how many shock cycles a given metal oxide coating can withstand before a given degree of degradation, if any, is observed. Thus, in some embodiments of the present invention, the at least one metal oxide coating withstands at least one, at least five, at least ten, at least twenty-five, at least fifty, or at least one hundred thermal shock cycles from room temperature to liquid nitrogen temperature. [00150] The nanocrystalline grains resulting from some embodiments of the methods of the present invention have an average size, or diameter, of less than about 50 nm. In some embodiments, nanocrystalline grains of metal oxide have an average size ranging from about 1 nm to about 40 nm or from about 5 nm to about 30 nm. In another embodiment, nanocrystalline grains have an average size ranging from about 10 nm to about 25 nm. In further embodiments, nanocrystalline grains have an average size of less than about 10 nm, or less than about 5 nm.

[00151] In other embodiments, the invention relates to metal oxide coatings (whether infused, thin film, or both infused and thin film) and articles comprising such coatings, in which the coatings contain two or more rare earth metal oxides and at least one transition metal oxide. Further embodiments of the invention relate to metal oxide coatings (and articles comprising them), containing ceria, a second rare earth metal oxide, and a transition metal oxide. Some embodiments relate to metal oxide coatings (and articles comprising them), containing yttria, zirconia, and a second rare earth metal oxide.

[00152] In some embodiments, the metal compound applied to the surface comprises a cerium compound, and the metal oxide coating comprises cerium oxide (or ceria). In other embodiments, the metal compound applied to the surface comprises a zirconium compound, and the metal oxide coating comprises zirconia. In yet other embodiments, a solution comprising both a cerium compound and a zirconium compound is applied, and the resulting metal oxide coating comprises ceria and zirconia. In some cases, the zirconia formed by the process of the invention comprises crystal grains having an average size of about 3-9 nm, and the ceria formed by the process of the invention comprises crystal grains having an average size of about 9-18 nm. The nanostructured zirconia can be stabilized in some embodiments with yttria or other stabilizing species alone or in combination. In still other embodiments, the metal oxide coating comprises zirconia, yttria, silica, or alumina, each alone or in combination with one or both of the others.

[00153] In additional embodiments, the method of the invention further includes a step of applying an organosiloxane-silica composition over the formed oxide coating and exposing the coated substrate to an environment that will remove volatile components from the composition without decomposing organo-silicon bonds. Moreover, other treatments can be performed after the formation of an oxide coating. As explained herein, additional metal oxide coatings, which can be the same or different, can be added. In some embodiments, the metal oxide(s) can be etched, polished, carburized, nitrided, painted, powder coated, plated, anodized, or combinations of two or more of the foregoing. In some embodiments, the at least one metal oxide serves as a bond coat for at least one additional coating. Such additional coatings need not be formed according to the present invention. Some embodiments provide a metal oxide bond coat that allows an additional coating that would not adhere to the surface as well in the absence of the bond coat. In addition, the substrate can be subjected to a thermal treatment, either before or after a metal oxide coating is formed on the substrate. For example, a substrate having a metal oxide coating in accordance with the present invention can be annealed at high temperature to strengthen the substrate. In another example, a substrate can be held near absolute zero before or after a metal oxide coating is formed on the substrate. Suitable temperatures for thermal treatment range from nearly 0 K to several thousand K, and include liquid hydrogen, liquid helium, liquid neon, liquid argon, liquid krypton, liquid xenon, liquid radon, liquid nitrogen, liquid oxygen, liquid air, and solid carbon dioxide temperatures, and temperatures obtained by mixtures, azeotropes, and vapors of those and other materials.

[00154] The methods of the present invention can be used during or after manufacturing a given component of a system vulnerable to corrosion and/or biofouling. For example, one or more oxide coatings can be applied to a pipe section as it is manufactured, or after the pipe is assembled into a fluid processing or transport system. Or, in certain embodiments, a pipe section can be removed from a system, transported to a treatment site, treated, and returned and reassembled into the system from which it came. Optionally, the pipe section can be assembled into another system. In that way, systems can be scavenged for useful components, which components are then provided at least one metal oxide coating, and then those components can find further use in another system.

[00155] Moreover, in some embodiments, the methods of the present invention can be incorporated into conventional manufacturing steps. For example, after pipes are welded, often they are subjected to a heat treatment to relieve the stresses introduced by the welding process. In some embodiments of the present invention, at least one metal compound is applied after welding and before that heat treatment. In those embodiments, that one heat treatment converts at least one metal compound into at least one metal oxide and relieves welding-induced stresses.

[00156] The process of the invention may permit the use of coatings on a wide variety of materials, including application of CeO₂ and ZrO₂ coatings to ceramics and/or solid metals previously not thought possible of being coated with these materials. Some embodiments of the present invention provide a relatively low temperature process that does not damage or distort many substrates, does not produce toxic or corrosive materials, and can be done on site, or "in the field" without the procurement of expensive capital equipment. [00157] Additionally, the nature of the resulting interstitial boundaries of the invention's nanocrystalline structures in various embodiments can be comprised of chosen ingredients so as to increase ionic conductivity while decreasing electron conductivity, or can be comprised of chosen ingredients so as to increase the material's mixed conductivity, or to modify its porosity. In a similar fashion, many other properties may be altered through the judicious selection of various ingredients that are formulated as part of the metal compound composition of the invention.

[00158] In some embodiments of the present invention, a substrate which comprises at least a portion of a component's structure is placed within a vacuum chamber, and the chamber is evacuated. Optionally, the substrate can be heated or cooled, for example, with gas introduced into the chamber or by heat transfer fluid flowing through the substrate mounting structure. If a gas is introduced, care should be taken that it will not alter the substrate in an unintended manner, such as by oxidation of a hot iron-containing surface by an oxygen-containing gas. Introduced gas optionally can be evacuated once the substrate achieves the desired temperature. In one example, a pipe elbow can be plugged, and optionally suspended to expose the exterior of the pipe elbow while shielding the interior of the elbow. Vapor of one or more metal compounds, such as cerium(III) 2-hexanoate, enters the vacuum chamber and deposits on the exposed exterior. A specific volume of a fluid composition containing the metal compound can provide a specific amount of compound to the surface of the elbow within the vacuum chamber, depending on the size of the chamber and other factors. Optionally, a chosen gas is vented into the chamber and fills the vacuum chamber to a chosen pressure, in one example, equal to one atmosphere. The chamber is heated to a temperature sufficient to convert at least some of the compounds into oxides, for example, 450 °C, for a discrete amount of time sufficient for the conversion process, for example, thirty minutes. In this example, a ceria layer forms on the exterior of the pipe elbow. Optionally, the process can be repeated as many times as desired, forming a thicker coating of ceria on the substrate. In some embodiments, the component can be cooled relative to ambient temperature, such as, for example, to liquid nitrogen temperature, to aid the deposition process. In other embodiments, a reducing atmosphere may be used to convert at least a portion of the metal oxides to metal.

[00159] In other embodiments, the substrate comprises one or more polymers, such as polyvinyl chloride. The polymer substrate can be kept at lower temperatures sufficient to prevent the degradation of the substrate during the heating process, for example, at liquid nitrogen temperatures while the metal compound converts to the oxide due to any technique that heats the metal compound but not the substrate to a significant degree. Examples of such heating techniques include flash lamps, lasers, and microwave heating. In addition, materials that would become degraded by exposure to high temperatures can be kept at lower temperatures using the same techniques. For example, glasses, low-melting-temperature metals, polycarbonates, and similar substrates can be kept cooler while the at least one metal compound is converted to at least one metal oxide.

[00160] As used herein in reference to process gases used to carry out the process of the invention, the term "high temperature" means a temperature sufficiently high to convert the metal compound to metal oxide, generally in the range of about 200⁰C to about 1000 ⁰C, such as, for example, about 200 ⁰C to about 400 ⁰C, or about 400 ⁰C to about 500 ⁰C, about 500 ⁰C to about 650⁰C, about 650 ⁰C to about 800⁰C, or about 800⁰C to about 1000 ⁰C. At least one embodiment provides forming a first layer at about 450 ⁰C, forming more layers at about 250-300 ⁰C, and then forming a final layer at about 450 ⁰C. Process gases at even higher temperatures can be used, so that, when the gas is passed by the system during the process of some embodiments of the invention, the temperature of the outside surfaces of the system is within the range given above.

[00161] A given embodiment of the invention described herein may involve one or more of several basic concepts. For example, one concept relates to a surface treatment that generally meets above-described technical properties and can be manufactured at a low cost. Another concept relates to a method to form an oxide protective film on the surface of a metal, ceramic, glass, cermet, polymer, composite material, or other suitable material. Another concept relates to a two-step process adapted to form a prophylactic layer onto external surfaces of a system. Another concept is related to a means to apply a protective coating to an assembly of various components using a process to heat the system as a curing method for the coating.

[00162] In some embodiments of the invention, a protective coating may be formed on a substrate by applying a liquid metal compound composition to the substrate using a dipping process, spraying, vapor deposition, swabbing, brushing, or other known means of applying a liquid to an external surface of a pipe, conduit or process equipment. This liquid metal compound composition comprises at least one rare earth metal salt of a carboxylic acid and at least one transition metal salt of a carboxylic acid, in a solvent, in some embodiments. The surface, once wetted with the composition, is then exposed to a heated environment that will convert at least some of the metal compounds to metal oxides, thereby forming a protective coating on the substrate.

[00163] The metal oxide coatings resulting from the conversion process, such as thin films of nanocrystalline materials, are applied to material substrates to form one or more thin protective layers. Additional applications of the metal compounds followed by conversion environment exposure (e.g., heating the surface through means described above) may be done to create multiple layers of thin film oxides stacked one on another. [00164] The process may be used to create a nanocrystalline structure that comprises an oxygen containing molecule for chosen applications. Alternately, the resulting nanocrystalline structure may comprise a metal containing compound, a metal, a ceramic, or a cermet. [00165] One benefit to some embodiments of the invention is the ability to apply the metal compound composition to an assembled system and then to flush high temperature gases through the system to achieve the conversion process, resulting in a we 11 -dispersed metal oxide coating on all exterior surfaces. This is especially beneficial for welded piping systems, heat exchangers, and similar components which use welding for their assembly, said welding typically destroying whatever surface treatments were applied to the pipes, heat exchangers, or other parts prior to welding. The high temperature conditions of the welding process tend to destroy all protective coatings. The invention provides a way to create a final metal oxide coating covering all parts of the process system even after assembly. [00166] To create a less porous thin film, for some embodiments, material may be added to the base fluid to act as filler material. In this way, the porosity of the finished coating is altered through the inclusion of nanoparticles of chosen elements in the liquid metal compound composition prior to the exposure of the composition to an environment that will convert at least a portion of the metal compound(s) into metal oxides. The result is a more dense thin film.

[00167] Certain embodiments provide metal oxide coatings that resist, reduce, or inhibit the colonization or growth of one or more organisms, optionally with the assistance of one or more antibiological additives. Nanoparticles of silver, for example, can be applied to the surface before, during, and/or after applying the at least one metal compound, so that the silver nanoparticles impart an antimicrobial effect to the at least one metal oxide. See, e.g., U.S. Patent No. 6,379,712. Alternatively, the silver nanoparticles can be applied once the metal oxide has formed, for example, by electrospraying. In still other embodiments, the application of one or more antibiological additives and one or more metal oxide coatings to a surface can occur in any suitable order. In further embodiments, titanium dioxide nanoparticles can accompany the at least one metal oxide coating to impart antimicrobial effects due to the absorption of UV light. See, e.g., A. Fujishima and T. N. Rao, 70 Pure App. Chem. (1998) 2177-87. Antibiological additives are used alone or in combination. Antibiological additives can appear in the metal compound composition, for example, in an amount of about 1 g to about 100 g of additive per kilogram of metal compound composition. [00168] In some applications, where it is desirable to reduce a metal oxide to a pure metal, the treated substrate may be exposed to a reducing agent, such as hydrogen or other known reducing agent using known means for oxide reduction. For example, 7 % hydrogen in argon heated to 350 ⁰C can be used to form platinum in certain embodiments. Other metals that may be desired, such as for catalytic purposes, for example, include but are not limited to platinum, palladium, rhodium, nickel, cerium, gold, silver, copper, zinc, lead, rhenium, ruthenium, and combinations of two or more thereof. [00169] As described above, the method of the invention may be used to provide prophylactic coatings to external surfaces of all manner of man-made systems, and has particular utility in the area of fluid transport or processing systems in the petroleum and natural gas industries, where corrosion is a particular problem in pipelines and processing equipment.

[00170] In some embodiments, the method of the invention provides an effective barrier against corrosive attack. Because the resulting surface coating provides an effective barrier between the material of the process equipment (often metal, such as iron or steel) and the environment, electrochemical and other reactions between the metal and the environment are effectively reduced or prevented in still other embodiments. This is particularly important for stainless steel piping systems, where the high temperatures involved in welding of the steel causes chromium (the primary passivating element in stainless steel) to migrate to grain boundaries, creating a galvanic couple between high Cr and low Cr areas, which can lead to corrosive attack. Because the method of the invention allows application of the coating after the welds have been formed (and any high temperature damage has occurred) in some embodiments, areas of the system adjacent to the weld are insulated from exposure to potentially corrosive environments.

[00171] The materials that can be protected according to the present invention include any material that can receive a protective coating of a metal oxide. Such materials include, for example, metals, ceramics, glasses, and cermets, as well as composites and polymers that can withstand the process conditions for converting the metal carboxylate into metal oxide. The metals that can be protected include, but are not limited to, substantially pure metals, alloys, and steels, such as, for example, low alloy steels, carbon steels, stainless steels, 300 series stainless steel, 400 series stainless steel, nickel base alloys, high-chromium steels, and high-molybdenum steels.

[00172] The industrial, infrastructural, and commercial systems and components thereof that can be protected according to the present invention are not limited. Petroleum refineries; petrochemical processing plants; petroleum transport and storage such as pipelines, fuel transport vehicles, and gas station fuel tanks and pumps; industrial chemical manufacture, storage, and transportation; industrial systems and components for manufacturing, storage, and transportation that involve particulate matter; sandblasting equipment; vehicles and components thereof including but not limited to vehicular suspension systems and body panels; military vehicles including but not limited to tanks, armored personnel carriers, mine-resistant ambush-protected vehicles, and components thereof; tracked and wheeled vehicles and components thereof; weapons systems and components thereof, including, for example, artillery gun barrels, small arms, missiles, rockets, launch structures, and components thereof; oil tankers and other ocean-going vessels including warships, cargo ships, cruise ships, research vessels, salvage vessels, barges, submarines, and components thereof; other water-borne craft; aircraft, such as helicopters, airplanes, unmanned aerial vehicles, missiles, rockets, space craft, and components thereof; and food and dairy processing systems; dams, including but not limited to hydroelectric power generation dams and components thereof including but not limited to turbines; power plants; power transmission infrastructure including wire towers and transformers; transportation infrastructure including bridges, overpasses, highway structures, roadway structures, storm drains, man-hole covers, tunnels, traffic light poles, traffic signs and their posts, poles, and scaffolding; railroads, railcars, and locomotives and components thereof; water processing and transport infrastructure, including sewers, water treatment plants and components thereof, pipes, fire hydrants, and the like; buildings and components thereof, including but not limited to girders, rainwater conduits, fire sprinklers, and HVAC equipment; hardware including bolts, screws, nuts, fasteners, handles, grips, ladder rungs, and crew platforms; among many others, and components of any of the foregoing, can benefit from the present invention.

EXAMPLES

Example 1

[00173] Five 2" x 2" coupons of mirror-finish SS304 steel (McMaster-Carr) were individually designated "Uncoated," "Zircon," "Glass," "YSZ," and "Clay." Those compositions mimic chemically and thermally inert materials by the same names known in nature and industry, in an inventive manner. A wide range of similar materials can suggest additional compositions to be used as embodiments of the present invention. The "Uncoated" coupon was given no coating, to function as the control. Each of the other coupons were coated on one side with the following compositions in accordance with embodiments of the present invention:

Zircon: Zirconium 2-ethylhexanoate (28 % wt. of the final composition, Alfa-Aesar), silicon

2-ethylhexanoate (33.5 % wt., Alfa-Aesar) and chromium 2-ethylhexanoate (I % wt., Alfa- Aesar) were mixed into 2-ethyIhexanoic acid (37.5 % wt, Alfa-Aesar), and the composition was spin-coated onto the steel substrate.

Glass: Silicon 2-ethylhexanoate (74 % wt., Alfa-Aesar), sodium 2-ethylhexanoate (5.2 % wt., Alfa-Aesar), calcium 2-ethylhexanoate (1 1 % wt., Alfa-Aesar), and chromium 2- ethylhexanoate (1.4 % wt., Alfa-Aesar) were mixed into 2-ethylhexanoic acid (8.4 % wt., Alfa-Aesar), and the composition was spin-coated onto the steel substrate.

YSZ: Yttrium 2-ethylhexanoate powder (2.4 % wt., Alfa-Aesar) was dissolved into 2- ethylhexanoic acid (60 % wt., Alfa-Aesar) with stirring at 75-80 ⁰C for one hour. Once the composition was cooled to room temperature, zirconium 2-ethylhexanoate (36.6 % wt., Alfa- Aesar) and chromium 2-ethylhexanoate (1 % wt., Alfa-Aesar) were mixed in. The composition was spin-coated onto the steel substrate.

Clay: Aluminum 2-ethylhexanoate (15 % wt., Alfa-Aesar), silicon 2-ethylhexanoate (45 % wt., Alfa-Aesar), and chromium 2-ethylhexanoate (2 % wt., Alfa-Aesar) were mixed into 2- ethylhexanoic acid. This composition was handbrushed onto the substrate, due to the viscosity of the composition. The composition apparently reacted with moisture in the air and began to solidify, making application difficult.

[00174] The coated steel coupons were placed in a vacuum oven, and evacuated to about 20-60 millitorr. The coupons were heated to 450 ⁰C, and then allowed to cool to room temperature. The process of depositing and heating was repeated to apply eight coatings of the appropriate composition on each coupon.

[00175] Each coated coupon was assembled into a test cell having a glass cylinder (I" inner diameter x 1.125" tall) clamped to the coated portion of the coupon. A rubber gasket formed a seal between the glass cylinder and the coupon. Aqua Regia was prepared from HNO₃ (I part, by vol., 70%, stock # 33260, Alfa-Aesar) and HCl (3 parts, by vol., -37%, stock # 33257, Alfa-Aesar), poured into the glass cylinder, and allowed to contact the coupon for one hour. Then, the coupon was removed, rinsed, and photographed. The photographs of the tested coupons appear in Figures I -5.

[00176] Aqua Regia, so-called because it is known to dissolve noble metals such as gold and platinum, severely etched the Uncoated stainless steel coupon. See Figure I . The

Zircon coupon, in contrast, remains largely unetched, showing only small spots. See Figure 2. The Glass coupon also remains largely unetched, showing faint scratch-like features. See Figure 3. The YSZ coupon shows significant etching. See Figure 4. The Clay coupon also shows etching, although less severe than the Uncoated coupon. See Figure 5.

[00177] On a scale of 0-10, with 0 representing severe etching and 10 representing complete protection, the coatings exhibited the following performance:

Coupon Performance

Uncoated 0

Zircon 8

Glass 7-8

YSZ 0-1

Clay 0-1

[00178] Observation of the Zircon and Glass coupons at magnifications of 100x to

1,00Ox before exposure to Aqua Regia revealed uniform, non-porous, mostly amorphous coatings. Observation of the YSZ coupon at those same magnifications revealed a surface coating having a crystalline structure. Observation of the Clay coupon revealed uneven coverage, likely due to the humidity-catalyzed reaction and premature solidification. Preparation and application of the Clay composition in a moisture and/or oxygen-free environment may improve the Clay coating's characteristics and performance. [00179] These results demonstrate protection of a steel substrate in a highly-corrosive environment by coatings prepared in accordance with the present invention. These results also demonstrate easy experiments for testing metal oxide coatings to assess how they might perform in a given environment.

[00180] Similar experiments can be done in other environments to determine how metal oxide coatings might perform in those environments. The skilled artisan will recognize that compositions that did not perform well against Aqua Regia may perform well in other environments. For example, it is believed that the YSZ coating reduces or prevents coke buildup. Furthermore, a composition's performance depends in part on the application and conversion conditions. For example, the Clay composition is expected to perform well if it is applied and converted in a suitable environment, as discussed above. Example 2 [00181] Figure 6 shows a TEM micrograph at about 2 million x magnification of a stainless steel SS304 substrate (104) having eight coats of an yttria/zirconia composition (102). The figure illustrates an infused coating, labeled Oxide-To-Substrate Interlayer (106). In this example, the infused coating is about 10 nm thick. The TEM also shows crystal planes, indicating the nanocrystalline nature of the yttria/zirconia. Example 3

[00182] The exterior surfaces of an oil pipeline section are cleaned and then wetted with a well-stirred room temperature composition containing cerium(IIl) 2-ethylhexanoate (203 g; all weights are per kilogram of final composition), chromium(IIl) acetylacetonate (10.1 g), and cerium(IV) oxide nanoparticles (10.0 g, 10-20 nm, Aldrich) in 2-ethylhexanoic acid (777 g). The composition is applied to the section by spraying the surface with the composition using a large-scale paint-sprayer. Steam at 500⁰C is passed through the pipe section for 30 minutes, and then the pipe section is allowed to cool. A substantially non- porous cerium oxide coating stabilized by chromium oxide forms on the exterior surface of the pipe section. Example 4

[00183] Under an ethanol-saturated nitrogen atmosphere, the cleaned forks of a boat forklift are wetted with a well-stirred composition containing titanium(IV) ethoxide in ethanol (500 g, 20 % Ti, Aldrich) and dry ethanol (500 g), by dipping the forks into the composition. After excess composition is allowed to drip from the forks, the forks are baked under dry nitrogen at 450 ⁰C for fifteen minutes, and the forks are allowed to cool under a flow of room-temperature nitrogen. Analysis will reveal a titanium dioxide coating on the surface of the forks, which will exhibit an antimicrobial effect under UV excitation. Example 5

[00184] A clean automobile exhaust manifold is dipped in a stirred bath containing a first composition that contains zirconium(IV) 2,2,6,6-tetramethyl-3,5-heptanedionate (459 g), yttrium(lll) 2,2,6,6-tetramethyl-3,5-heptanedionate (72.9 g), and hexanes (to I kg) so the composition contacts exterior surfaces. Optionally, openings can be plugged so the first composition does not contact the interior surfaces. The manifold is removed from the composition, suspended, and rotated to allow excess composition to drip into the bath. Microwave radiation irradiates exterior surfaces for ten minutes, and an yttria-stabilized zirconia coating forms on the exterior of the manifold. Optionally, the manifold can be cooled to room temperature and then slowly lowered into a liquid nitrogen bath for a time. [00185] As previously stated, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. It will be appreciated that many modifications and other variations that will be appreciated by those skilled in the art are within the intended scope of this invention as claimed below without departing from the teachings, spirit, and intended scope of the invention. Furthermore, the foregoing description of various embodiments does not necessarily imply exclusion. For example, "some" embodiments may include all or part of "other" and "further" embodiments within the scope of this invention.

Claims

WE CLAIM:

1. A method for preventing or reducing corrosion on an exterior surface, comprising: applying at least one metal compound to the surface; and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide, wherein the at least one metal oxide is resistant to corrosion.

2. A method for preventing or reducing biofouling on an exterior surface, comprising: applying at least one metal compound to the surface; and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide on the surface, wherein the at least one metal oxide is resistant to biofouling.

3. A method for forming at least one metal oxide on a surface subject to particulate erosion, comprising: applying at least one metal compound to the surface; and exposing the surface with the applied at least one metal compound to an environment that will convert at least some of the compound to at least one metal oxide.

4. A method for forming at least one metal oxide on a surface subject to a high-temperature environment, comprising: applying at least one metal compound to the surface; and converting at least some of the at least one metal compound into at least one metal oxide, wherein the at least one metal oxide withstands the high-temperature environment.

5. The method of any one of claims 1, 2, 3, or 4, wherein the at least one metal compound comprises at least one metal carboxylate, at least one metal alkoxide, at least one metal β- diketonate, or a combination of any of the foregoing.

6. The method of any one of claims 1, 2, 3, or 4, wherein the surface is present in a petroleum refinery, a petroleum pipeline, an oil tanker, a food processing system, a dairy processing system, a chemical manufacturing plant, or a military weapons system.

7. A method for preventing or reducing corrosion on a surface of an industrial fluid processing or transport system, or a component thereof, wherein the surface is subject to a high-temperature environment, comprising: applying at least one metal compound to the exterior surface; and converting at least some of the at least one metal compound to at least one metal oxide; wherein the at least one metal oxide is resistant to corrosion; and wherein the at least one metal oxide withstands the high-temperature environment.

8. The method of claim 7, wherein the at least one metal compound comprises at least one metal carboxylate, at least one metal alkoxide, at least one metal β-diketonate, or a combination of any of the foregoing.

9. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises at least one metal oxide chosen from the oxides of:

Lithium, Beryllium, Sodium, Magnesium, Silicon, Potassium, Calcium, Gallium, Germanium, Arsenic, Bromine, Rubidium, Strontium, Technetium, Ruthenium, Rhodium, Palladium, Indium, Tin, Antimony, Tellurium, Cesium, Barium, Tantalum, Tungsten, Rhenium, Osmium, Iridium, Gold, Mercury, Thallium, Lead, Bismuth, Radium, Actinium, Thorium, Protactinium, Uranium, Neptunium, Plutonium, Americium, Curium, Berkelium, Californium, Einsteinium, Fermium, Mendelevium, Nobelium, Lawrencium, and combinations thereof.

10. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises at least one metal oxide chosen from the oxides of:

Aluminum, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Yttrium, Zirconium, Niobium, Molybdenum, Silver, Cadmium, Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Hafnium, Platinum, and combinations thereof.

1 1. The method of any one of claims 1 , 2, 3, 4, or 7, wherein the at least one metal compound is present in a metal compound composition that further comprises at least one nanoparticle.

12. The method of claim 1 1, wherein the at least one nanoparticle is chosen from Al₂O₃, CeO₂, Ce₂O₃, TiO₂, ZrO₂, Ag, and combinations of two or more of the foregoing.

13. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises more than one layer.

14. The method of any one of claims 1, 2, 3, 4, or 7, wherein at least some of the at least one metal oxide is present in a thin layer of a nanocrystalline coating.

15. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises: at least one rare earth metal oxide, and at least one transition metal oxide.

16. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises at least two rare earth metal oxides.

17. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises ceria.

18. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises yttria and zirconia.

19. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises ceria and zirconia.

20. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide comprises yttria, zirconia, ceria, alumina, silica, or a combination of two or more of the foregoing.

21. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide is chosen from ZrO₂, CeO₂, Y₂O₃, TiO₂, Fe₂O₃, NiO, Al₂O₃, Cr₂O₃, Mo₂O₃, HfO₂, La₂O₃, Pr₂O₃, Nd₂O₃, Sm₂O₃, Eu₂O₃, Gd₂O₃, Tb₂O₃, Dy₂O₃, Ho₂O₃, Er₂O₃, Tm₂O₃, Yb₂O₃, Lu₂O₃, and combinations of two or more of the foregoing.

22. The method of any one of claims 1, 2, 3, 4, or 7, wherein the at least one metal oxide further comprises platinum, palladium, rhodium, nickel, cerium, gold, silver, copper, zinc, lead, rhenium, ruthenium, chrome, tin, or a combination of two or more of the foregoing.

23. The method of claim 7, wherein the surface is present in an industrial fluid processing or transport system and is chosen from a petroleum refinery, petroleum pipelines, an oil tanker, a food processing system, a dairy processing system, or a chemical manufacturing plant.