HK1240468B - Anti-microbial coating and method to form same - Google Patents

Description

Antimicrobial coating and method of forming the same

Field of the Invention

Embodiments generally relate to antimicrobial coating compositions and methods of using the coating compositions. In certain embodiments, the coating composition comprises a photocatalyst. In certain embodiments, the photocatalyst comprises a titanium-oxygen moiety. In certain embodiments, the coating composition comprises a silane.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood from the following detailed description when read in conjunction with the accompanying drawings, wherein like reference numerals are used to represent like elements, and wherein:

Figure 1 graphically illustrates the number of nosocomial Clostridium difficile (C-difficile) infections in the Glendale Memorial Hospital ICU from January 2012 to February 2014;

Figure 2 graphically illustrates the number of nosocomial Clostridium difficile infections at Glendale Memorial Hospital (excluding the ICU) from January 2012 to February 2014;

FIG3 shows the antimicrobial efficacy data at 0 hours after inoculation of treated coupons;

FIG4 lists antimicrobial efficacy data 4 hours after inoculation of treated specimens, including data for ABS-G2020 and ABS-G2030 treated Formica specimens;

FIG5 lists antimicrobial efficacy data 4 hours after inoculation of treated specimens, including data for ABS-G2020 and ABS-G2030 treated stainless steel specimens;

Figure 6 lists a surface time-kill study evaluating two coating formulations against murine norovirus using 6-hour contact time data;

FIG7 lists CFU/mL data for each of three coating formulations, wherein each formulation does not include one or more titanium-oxide moieties;

FIG8 lists the log reduction data for three formulations evaluated, each of which did not include one or more titanium-oxide moieties;

FIG9 lists the percentage reduction data for three formulations used, each of which does not include one or more titanium-oxide moieties;

FIG10 lists antimicrobial efficacy data for certain electrostatic spray embodiments;

FIG11 lists antimicrobial efficacy data for certain electrostatic spray embodiments;

FIG12 lists antimicrobial efficacy data for certain electrostatic spray embodiments;

FIG13 lists antimicrobial efficacy data for certain non-electrostatic spray embodiments;

FIG14 lists antimicrobial efficacy data for certain non-electrostatic spray embodiments;

FIG15 lists antimicrobial efficacy data for certain non-electrostatic spray embodiments;

Detailed Description of the Preferred Embodiments

In the following description, the present invention is described in preferred embodiments with reference to the accompanying drawings, wherein like numerals represent like or similar elements. Reference throughout this specification to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present invention. Therefore, throughout this specification, appearances of the phrases "in one embodiment," "in an embodiment," and similar language may, but do not necessarily, all refer to the same embodiment.

In one or more embodiments, the features, structures or characteristics described herein may be combined in any suitable manner. In the following description, many specific details are enumerated to provide a comprehensive understanding of the embodiments of the present invention. However, those skilled in the relevant art will appreciate that the present invention may be practiced without one or more specific details, or with other methods, components, materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid blurring the various aspects of the present invention.

In certain embodiments of the compositions and methods of the present invention, a coating is formed on a surface, wherein the coating comprises a plurality of silicon-oxygen bonds. In certain embodiments of the compositions and methods of the present invention, a coating is formed on a surface, wherein the coating comprises a plurality of titanium-oxygen bonds in combination with a plurality of silicon-oxygen bonds.

In certain embodiments, a coating comprising multiple titanium-oxide bonds in combination with multiple silicon-oxygen bonds is formed by disposing a silane in combination with one or more compounds comprising one or more titanium-oxygen bonds on a surface. In certain embodiments, a coating comprising multiple titanium-oxide bonds in combination with multiple silicon-oxygen bonds is formed by first disposing one or more compounds comprising one or more titanium-oxygen bonds on a surface, and then disposing a silane on the surface and on the one or more compounds comprising one or more titanium-oxygen bonds. In certain embodiments, a coating comprising multiple titanium-oxide bonds in combination with multiple silicon-oxygen bonds is formed by simultaneously disposing one or more compounds comprising one or more titanium-oxygen bonds and a silane on a surface.

In certain embodiments, the silanes of the present invention include Compound 1.

In certain embodiments, R1 is selected from OH and O-alkyl. In certain embodiments, R2 is selected from OH and O-alkyl. In certain embodiments, R3 is selected from OH and O-alkyl. In certain embodiments, R4 is selected from OH and O-alkyl, alkyl, substituted alkyl, including γ-chloropropyl, γ-aminopropyl, and quaternary ammonium substituted alkyl.

In certain embodiments, the silanes of the present invention include trihydroxysilane 2.

In certain embodiments, the silanes of the present invention include silanetriol 2, wherein R4 is an alkyl group. In other embodiments, the silanes of the present invention include silanetriol 2, wherein R4 is an alkyl group having an amino moiety. In yet another embodiment, the silanes of the present invention include silanetriol 2, wherein R4 is an alkyl group having a chlorine substituent. In still other embodiments, the silanes of the present invention include silanetriol 2, wherein R4 is an alkyl group having a quaternary ammonium group.

Silsesquioxane is an organosilicon compound3, where Si represents the element silicon and O represents the element oxygen.

In certain embodiments, upon application of the silanes 1 or 2 of the present invention to hard surfaces (i.e., walls, doors, tables, and the like) or soft surfaces (i.e., mattresses, drapes, furniture pads, and the like), the resulting coating disposed on the hard/soft surface comprises a plurality of silsesquioxane structures. In certain embodiments, upon application of the silanes 1 or 2 of the present invention in combination with one or more compounds containing titanium-oxygen moieties to hard surfaces (i.e., walls, doors, tables, and the like) or soft surfaces (i.e., mattresses, drapes, furniture pads, and the like), the resulting coating disposed on the hard/soft surface comprises a plurality of silsesquioxane structures 3 in combination with a plurality of titanium-oxygen structures.

Oxidation is the loss of electrons or increase in oxidation state by a molecule, atom, or ion. Substances that can oxidize other substances are considered oxidizing or possess oxidizing properties and are referred to as oxidizing agents or oxidizing agents. In other words, an oxidizing agent removes electrons from another substance and, as a result, is itself reduced. Because it "accepts" electrons, it is also known as an electron acceptor.

In chemistry, photocatalysis is the acceleration of a photoreaction in the presence of a catalyst. In catalytic photolysis, light is absorbed by an adsorbed substrate. In photocatalytic catalysis, photocatalytic activity (PCA) depends on the catalyst's ability to generate electron-hole pairs, which in turn generate free radicals (hydroxyl radicals: ·OH) that can undergo secondary reactions. This understanding has become possible since the discovery of water electrolysis using titanium dioxide.

When exposed to ultraviolet (UV) light, certain titanium-oxide morphologies exhibit photocatalytic properties. When exposed to UV light, the titanium-oxide moieties of the present invention generate electron-hole pairs, which generate free radicals (e.g., hydroxyl radicals). The degree of photocatalytic strength varies with the type of titanium-oxide, for example, anatase titanium oxide (particle size of about 5 to 30 nanometers) is a stronger photocatalyst than rutile titanium oxide (particle size of about 0.5 to 1 micron).

In certain embodiments of the compositions and methods of the present invention, a coating is formed on a surface, wherein the coating comprises a plurality of titanium-oxygen bonds, wherein the coating is formed by disposing titanium-oxygen moieties of the present invention on the target surface.

In certain embodiments of the compositions and methods of the present invention, a coating is formed on a surface, wherein the coating comprises a plurality of silicon-oxygen bonds, wherein the coating is formed by disposing Silane 1 of the present invention on the surface.

In certain embodiments of the compositions and methods of the present invention, a coating is formed on a surface, wherein the coating comprises a plurality of titanium-oxygen bonds, wherein the coating is formed by disposing a mixture of a peroxotitanic acid solution and a peroxo-modified anatase sol (collectively referred to as the "titanium-oxygen portion") on the surface.

In certain embodiments, the titanium-oxygen portion of the present invention comprises a mixture of up to about a total of 1 wt% loaded peroxytitanic acid solution and peroxy-modified anatase sol. In certain embodiments, the titanium-oxygen portion of the present invention comprises about 0.5 wt% peroxytitanic acid solution combined with about 0.5 wt% peroxy-modified anatase sol.

Methods for preparing both peroxotitanic acid solutions and peroxo-modified anatase sols are disclosed in the Journal of Sol-Gel Science and Technology, Vol. 22, No. 1-2, September 2001, pp. 33-40. This publication discloses, inter alia, Reaction Scheme 1, shown immediately below, which outlines the synthesis procedures for both peroxotitanic acid solutions and peroxo-modified anatase sols.

Reaction Scheme 1:

In the following examples, coatings ABS-G2015, ABS-G2020, and ABS-G2030 are mentioned. Coating formulation ABS-G2015 includes a siloxane-containing compound having structure V:

Coating formulation ABS-G2015 further includes a titanium-oxygen moiety. The order of placement on the surface is not critical. In certain embodiments, the siloxane-containing compound is first placed on the surface, and the titanium-oxygen moiety is placed on the siloxane-containing compound. In other embodiments, the titanium-oxygen moiety is first placed on the surface, and the siloxane-containing compound is placed on the surface treated with the titanium-oxygen moiety. In yet another embodiment, the titanium-oxygen moiety and the siloxane-containing compound are first premixed, and the resulting mixture is placed on the surface of the substrate.

Coating formulation ABS-G2020 includes a siloxane-containing compound having structure VI:

Coating formulation ABS-G2020 further includes a titanium-oxygen moiety. The order of placement on the surface is not critical. In certain embodiments, the siloxane-containing compound is first placed on the surface, and the titanium-oxygen moiety is placed on the siloxane-containing compound. In other embodiments, the titanium-oxygen moiety is first placed on the surface, and the siloxane-containing compound is placed on the surface treated with the titanium-oxygen moiety. In yet another embodiment, the titanium-oxygen moiety and the siloxane-containing compound are first premixed, and the resulting mixture is placed on the surface of the substrate.

Coating formulation ABS-G2030 includes a siloxane-containing compound having structure VII:

Coating formulation ABS-G2030 further includes a titanium-oxygen moiety. The order of placement on the surface is not critical. In certain embodiments, the siloxane-containing compound is first placed on the surface, and the titanium-oxygen moiety is placed on the siloxane-containing compound. In other embodiments, the titanium-oxygen moiety is first placed on the surface, and the siloxane-containing compound is placed on the surface treated with the titanium-oxygen moiety. In yet another embodiment, the titanium-oxygen moiety and the siloxane-containing compound are first premixed, and the resulting mixture is placed on the substrate surface.

The following examples are provided to further illustrate how to prepare and use the present invention to those skilled in the art. However, these examples are not intended to limit the scope of the present invention.

Example 1

This Example 1 evaluated the antimicrobial efficacy of coatings ABS-G2015, ABS-G020, and ABS G-2030 against murine norovirus. Murine norovirus (MNV) is the species of norovirus that infects mice. Norovirus is the most common cause of viral gastroenteritis in humans. It affects people of all ages. The virus is spread, inter alia, through aerosolization and subsequent contamination of surfaces. The virus affects approximately 267 million people and causes over 200,000 deaths annually; these deaths typically occur in less developed countries and among the very young, elderly, and immunosuppressed.

The samples of this Example 1 were prepared using the procedure outlined immediately below herein.

Process

Put on sterile gloves.

The specimens were prepared by first wiping with isopropyl alcohol and allowing to dry.

Using a microfiber cloth, clean the specimen with surface cleaner.

Hold the sprayer about 8 inches from the surface to be cleaned.

Let the spray sit for 1-3 minutes and wipe it off. If the area is extremely dirty, allow the cleaner to sit longer, or apply a second spray and wipe.

Wipe the surface with a clean, damp sponge or cloth.

Allow the surface to dry completely.

Use gloved hands to check the consistency of the sample.

A 10% by volume solution of the selected silane in methanol (MeOH) was prepared (10 ml silane in 90 ml MeOH).

Triethanolamine was prepared as a 10 vol% solution in MeOH.

Combine the triethanolamine solution and the silane solution in a 1:1 ratio (ie, 100 ml of triethanolamine solution to 100 ml of silane solution) on a stir plate at room temperature.

Silane application

Add the silane/triethanolamine solution from [00041] to the applicator container.

Tightly tighten the liquid hose/cap assembly onto the container.

Connect the air hose from the compressor to the air fitting on the spray applicator.

Connect the fluid hose to the fluid fitting on the spray applicator.

Plug the power cord into an appropriate outlet. Turn on the air compressor.

The optimal spray distance is at least 36 to 48 inches from the target surface.

Hold the gun at a right angle to the target surface and spray.

Spray just barely enough to create a glisten on the target surface. Do not oversaturate the surface.

The target surface is allowed to dry, i.e., at least 90% by weight of the methanol liquid carrier is allowed to evaporate, to provide a deposit consisting essentially of the selected silane and triethanolamine. The deposit on the target surface consists of at least 33% by volume of the selected silane, at least 33% by volume of triethanolamine, and up to about 33% by volume of residual methanol carrier liquid.

Prior to applying the titania portion of the present invention, rinse the spray gun (one for each product unless two sprayers are used) with distilled water.

Application of titanium-oxygen moieties

Add the aqueous mixture of the titanium-oxo moiety of the present invention to the applicator container.

Tighten the liquid hose/cap assembly tightly on the container.

Connect the air hose from the compressor to the air fitting on the spray applicator.

Connect the fluid hose to the fluid fitting on the spray applicator.

Plug the power cord into an appropriate outlet. Turn on the air compressor.

The optimal spray distance is at least 36 to 48 inches from the target surface.

Hold the gun at a right angle to the target surface and spray.

Spray just barely enough to create a glisten on the target surface. Do not oversaturate the surface.

The target surface is allowed to dry, i.e., at least 90% by weight of the aqueous carrier liquid is allowed to evaporate, to provide a deposit consisting essentially of the titanium-oxo moieties of the present invention. The deposit on the target surface consists of at least 66% by volume of the titanium-oxo moieties of the present invention and up to about 33% by volume of residual aqueous carrier liquid.

After each day's use, clean the spray gun with distilled water according to the preparer's specifications.

Figures 4 and 5 list the antimicrobial efficacy data 4 hours after inoculation of the treated specimens. Figure 4 includes data for Formica specimens treated with ABS-G2020 and ABS-G2030. Figure 5 includes data for stainless steel specimens treated with ABS-G2020 and ABS G-2030.

In the assay, RAW (mouse macrophage) host cells were prepared in 96-well trays 24 hours prior to use.

On the day of testing, a stock vial of test virus, Murine Norovirus (titer = 5 x ¹⁰⁸ TCID50 units/ml) was removed from storage at -80°C. An organic soil load (heat-inactivated fetal bovine serum) was added to give a final concentration of 5%.

Using pre-sterilized surgical forceps, control (uncoated stainless steel and Formica) and coated test vehicles [ABS-G2015(SS), ABS-G2020(Form), ABS-G2030(Form), ABS-P2015(SS)] were placed into sterile Petri dishes (one per dish).

Virus inoculum (0.010 ml) was pipetted into the center of the control and test carriers and spread over a surface area of approximately 1 ⁱⁿ² using a sterile bent pipette tip.

A set of control carriers (based on the surface material type) were immediately harvested/neutralized by placing in a sterile stomacher bag containing 3 ml of neutralization solution (calf serum supplemented with 0.001% sodium thiosulfate and 0.001% sodium thiogluconate) to determine the counts at time 0. The bag was stomached at high speed for 120 seconds to release the virus from the carriers.

The remaining control and test vehicles were maintained under ambient conditions for each of the specified study exposure periods of 4 hours and 24 hours [positioning distance/configuration: approximately 68 inches (approximately 1.7 m) below two full spectrum lamps, inoculated side facing the light]. All vehicles were observed to dry out within 10 minutes of inoculation.

Once the respective contact times were complete, the control and test vehicles were neutralized by placing in sterile homogenization bags containing 3 ml of neutralization solution followed by digestion as described above.

At the beginning and end of each contact time, room temperature, relative humidity, and illuminance (lux) were measured and recorded.

Control and test vector eluates were serially diluted (1:10) and plated in six replicates on RAW host cells prepared for appropriate confluency.

Plates were observed every 24 to 48 hours to visualize viral pathogenic effect (CPE) and cytotoxicity.

Following the 9-day assay incubation period, the plates were formally scored.

For each test coating formulation, log10 and % reduction were calculated relative to the viral counts of the timed control (for each surface type). However, for the 24 hour contact time, it was not possible to calculate reduction due to insufficient virus recovery from the control carrier.

Neutralization confirmation was performed for each test coating formulation (except for ABS-P2015, which lacked a vehicle). One control vehicle and one of each test vehicle type were placed in a homogenization bag containing 3 ml of neutralizer and processed as described above. The eluate was serially diluted, and a low titer inoculum of the test virus (approximately 3-log 10) was added to each dilution tube relative to each control and test vehicle suspension. Aliquots (0.1 ml) of the suspension were then plated to assess the cytotoxicity level of the neutralized test material.

Example 2

This Example 2 utilizes three silanes, namely, ABS-G2015, AB-G2020, and ABS-G2030, in the coating formulation, but without any titanium-oxygen containing compounds. The methods of Example 1 in paragraphs [00044] through [00064] involving spray deposition of the silanes on the specimens are used in this Example 2. The methods of paragraphs [00065] through [00074] involving spray deposition of the titanium-oxygen portion are not used in this Example 2.

Figure 7 lists CFU/mL data for each of three coating formulations, wherein each formulation does not include one or more titanium-oxide moieties. Figure 8 lists log reduction data for the three formulations evaluated, wherein each formulation does not include one or more titanium-oxide moieties. Figure 9 lists the % reduction for the three formulations used, wherein each formulation does not include one or more titanium-oxide moieties.

Example 3

This Example 3 utilized the complete formulations ABS-G2015, AB-G2020, and ABS-G2030, wherein these coating formulations were applied to stainless steel coupons using the entire procedure of Example 1. In one set of experiments, the formulations were applied to the coupons using an electrostatic spray device. In another set of experiments, the formulations were applied to the coupons using a non-electrostatic spray assembly.

Figures 10, 11 and 12 list antimicrobial efficacy data for the electrostatic spray embodiment. Figures 13, 14 and 15 list antimicrobial efficacy data for the non-electrostatic spray embodiment.

Example 4

The study was conducted at Glendale Memorial Hospital and Health Center in Glendale, CA (the "Glendale Memorial Hospital Study"). The center has a 24-bed intensive care unit (ICU). The study was conducted between May 10 and September 30, 2013. The Glendale Memorial Hospital Study was designed to evaluate the antimicrobial efficacy of the coating composition ABS-G2015 described herein above, which was applied using the full method of Example 1 herein.

In the Glendale Memorial Hospital Study, the two-step spraying protocol described herein was applied to all ICUs to treat all surfaces in each room, including hard surfaces (beds, tray tables, bed rails, walls, etc.) and soft surfaces (drapes, cloth and vinyl covered chairs, etc.). More specifically, each surface was first electrostatically sprayed at room temperature using an aqueous composition formed by mixing octadecylaminodimethyltrihydroxysilylpropylammonium chloride ("quaternary amine silylate") in water at about 3.6 wt%.

Each surface was electrostatically coated with the titania moiety described herein above at room temperature approximately 15 minutes after electrostatic spraying with the aqueous quaternary silylated amine.

The treated surface was maintained at room temperature during the spray deposition of the aqueous silylated quaternary amine and during the spray deposition of the titanium-oxide portion. No high temperature heat treatment was performed on the treated surface, wherein the treated surface was heated to a temperature above about room temperature after completion of the two-step coating protocol.

Following the two-step spraying protocol, 95 specific sites within the ICU were selected for reproducible sampling at 1, 2, 4, 8, and 15 weeks. These selected sites included bed rails, bed controls, tray tables, and walls above drains. Samples were also collected from two ICU nursing stations and the waiting hall, including work surfaces, telephones, computer keyboards, chair arms, and coffee tables. During the study, all movable items were discreetly labeled and coded so that the same objects could be sampled.

Using a sponge stick containing Letheen broth (3M, St. Paul, MN), a 100 ^cm2 area was sampled to neutralize any residual disinfectant. After collection, the samples were immediately placed on ice packs and sent overnight to the University of Arizona for analysis by Professor Charles Gerba.

Figure 1 is a true and exact reproduction of the first picture provided by the Manager of Infection Prevention, Dignity Health/Glendale Memorial Hospital & Health Center. It illustrates the number of nosocomial Clostridium difficile infections in the Glendale Memorial Hospital ICU from January 2012 to February 2014.

Figure 1 shows that there were no nosocomial Clostridium difficile infections originating in the ICU between May 2013 and November 2013, except for September 2013. Therefore, Figure 1 shows a single nosocomial Clostridium difficile infection originating in the ICU over the course of 6 months between May 2013 and November 2013.

FIG1 further demonstrates that, with the exception of the 6-month period between May 2013 and November 2013, there was no other 6-month period during the 25-month period between January 2012 and February 2014 in which there was only a single nosocomial Clostridium difficile infection originating in the ICU.

During the first week of May 2013, all surfaces within the ICU were treated as described herein above as part of the Glendale Memorial Hospital Study. Figure 2 is a true and exact reproduction of the second image provided by the Manager of Infection Prevention, Dignity Health/Glendale Memorial Hospital & Health Center. It illustrates the number of nosocomial Clostridium difficile infections at Glendale Memorial Hospital (excluding the ICU) from January 2012 to February 2014.

Figure 2 shows that there were 1 to 8 nosocomial C. difficile infections in hospital areas outside the ICU during each of the 25 months except April 2013. During the May 2013 to November 2013 time period, Figure 2 shows a total of 20 nosocomial C. difficile infections at Glendale Memorial Hospital that originated outside the ICU.

Figures 1 and 2 show a single nosocomial Clostridium difficile infection originating in the ICU at Glendale Memorial Hospital and a total of 20 nosocomial Clostridium difficile infections originating outside the ICU at Glendale Memorial Hospital during the time period of May 2013 to November 2013.

Clostridium difficile colitis, or pseudomembranous colitis, is colitis (inflammation of the large intestine) from infection with Clostridium difficile, a type of spore-forming bacteria. It causes an infectious diarrhea called Clostridium difficile diarrhea. The latent symptoms of Clostridium difficile infection (CDI) often mimic some flu-like symptoms and can mimic the way illness flares up in people with colitis associated with inflammatory bowel disease. Clostridium difficile releases toxins that can cause swelling and diarrhea that can become severe, as well as unusual pain.

Clostridium difficile is transmitted from person to person via the fecal-oral route. The organism forms heat-resistant spores that are not killed by alcohol-based hand cleaners or conventional surface cleaning. Consequently, these spores persist in clinical settings for extended periods of time. For this reason, the bacterium can be cultured from nearly any surface.

C. difficile spores are extremely strong and can persist for extended periods in environments without food. The spores are resistant to drying and heating, and are also resistant to many forms of antibacterial cleaning agents. C. difficile can also persist in spore form for up to five months. The ability of C. difficile to survive in this resistant form poses a significant challenge to hospitals.

Because C. difficile forms heat-resistant spores that are not killed by alcohol-based hand cleaners or conventional surface cleaning, the data in Figures 1 and 2 demonstrate that treating hard and soft surfaces with ABS-G2015 necessarily reduced the presence of C. difficile spores within the Glendale Memorial Hospital ICU. The data in Figure 2 indicate that other hospital departments not treated with the ABS-G2015 coating composition experienced much greater levels of nosocomial C. difficile infection, further confirming the antimicrobial efficacy of the coating resulting from the application of ABS-G2015 against C. difficile spores.

In coating formulations ABS G2015, G2020, and G2030, depending on the stoichiometry of the triethanolamine and organosilane, one or more polymeric species are formed on the treated surface. In certain embodiments, as shown in Reaction Scheme 2, triethanolamine 9 and organosilane 1 react to form a linear polymer 10, where n is greater than or equal to 1 and less than or equal to about 10.

Reaction scheme 2

In other embodiments, as shown in Reaction Scheme 3, triethanolamine 9 and organosilane 1 react to form branched polymer 11.

Reaction Scheme 3

wherein in Reaction Scheme 3, x is greater than or equal to 1 and less than or equal to about 10, and wherein y is greater than or equal to 1 and less than or equal to about 10.

In other embodiments, and as shown in Reaction Scheme 4 , triethanolamine 9 and organosilane 1 react to form a crosslinked polymer 12 .

Reaction Scheme 4

wherein in Reaction Scheme 4, x is greater than or equal to 1 and less than or equal to about 10, and wherein y is greater than or equal to 1 and less than or equal to about 10, and wherein z is greater than or equal to 1 and less than or equal to about 10.

In certain embodiments, the organosilane of the present invention comprises tetraethyl orthosilicate 13. In certain embodiments, and as shown in reaction scheme 5, and depending on the stoichiometry of the starting materials 9 and 13, the crosslinked polymeric material 14 of the present invention is formed by reacting tetraethyl orthosilicate 13 and triethanolamine 9. Reaction scheme 5 illustrates a single Si atom having four different polymer chains derived therefrom. It will be understood by those skilled in the art that the crosslinked polymeric material 14 of the present invention comprises a very high crosslink density.

Reaction Scheme 5

wherein in reaction scheme 5, a is greater than or equal to 1 and less than or equal to about 10, and wherein b is greater than or equal to 1 and less than or equal to about 10, and wherein c is greater than or equal to 1 and less than or equal to about 10, and wherein d is greater than or equal to 1 and less than or equal to about 10.

In certain embodiments, and as shown in reaction scheme 6 and depending on the stoichiometry of starting materials 15 and 13, the crosslinked polymer material 16 of the present invention is formed by reacting tetraethyl orthosilicate 13 and diethanolamine 13. Reaction scheme 6 illustrates a single Si atom with four different polymer chains derived therefrom. It will be understood by those skilled in the art that the crosslinked polymer material 16 of the present invention comprises a very high crosslink density.

Reaction Scheme 6

wherein in Reaction Scheme 6, a is greater than or equal to 1 and less than or equal to about 10, and wherein b is greater than or equal to 1 and less than or equal to about 10, and wherein c is greater than or equal to 1 and less than or equal to about 10, and wherein d is greater than or equal to 1 and less than or equal to about 10.

While the preferred embodiments of the present invention have been described in detail, it should be apparent that modifications and variations of these embodiments may occur to those skilled in the art without departing from the scope of the invention.

Claims (6)

1. An antimicrobial coating formulation, comprising: (i) silanes having the following structure (1): Wherein, R1, R2, and R3 are OH, and R4 is γ-chloropropyl, γ-aminopropyl, or -( _CH2 ) ₃ - _N ⁺ ( _CH3 ) _2C18Cl- ^; (ii) Peroxytitanic acid and peroxy-modified anatase sol; and (iii) Triethanolamine. 2. The antimicrobial coating formulation of claim 1, wherein the silane is γ-chloropropylsilanetriol. 3. The antimicrobial coating formulation of claim 1, wherein the silane is γ-aminopropylsilanetriol. 4. A method for forming an antimicrobial coating on a surface, comprising: A first composition comprising the following substances is disposed on the surface: (i) silanes having the following structure (1): Where R1, R2, and R3 are OH, and R4 is γ-chloropropyl, γ-aminopropyl, or -( _CH2 ) ₃ - _N ⁺ ( _CH3 ) _2C18Cl- , ^and (ii) Triethanolamine; and A second composition comprising peroxytitanic acid and peroxy-modified anatase sol is disposed on the surface. 5. The method of claim 4, wherein the silane is γ-chloropropylsilanetriol. 6. The method of claim 4, wherein the silane is γ-aminopropylsilanetriol.