KR101025033B1 - Composite Films Comprising Planar Nanoporous Oxide Ceramic Membranes and Multi-functional Filters Using the Same - Google Patents

Abstract

The present invention relates to a multifunctional filter device for purifying indoor air, combustion gas, and exhaust gas, and to a composite membrane and a multifunctional filter for water treatment and purification of food, beverage, oil, blood, protein, virus, and the like. And an anodized nanoporous oxide ceramic film having a nano-sized straight through hole formed by patterning a metal in a predetermined pattern and then anodizing, and a composite film composed of a metal support part and a metal bonding part. The composite material comprising a plate-shaped anodized nanoporous oxide ceramic membrane and a multifunctional filter using the same, and the multifunctional filter is also a composite material coated with the composite membrane or coated with various metal catalyst materials or polymer functional materials It is formed by mixing and laminating the membranes. This provides better mechanical properties, heat and mechanical impact resistance, improves adhesion and connectivity with other structures, improves applicability to other devices, and provides a much larger specific surface area than conventional ceramic filters. By increasing the filtration efficiency and multifunctionality, there is an advantage that can simplify the structure and integration.

Filter Dialysis Purification Nanoporous Oxide Ceramic Membrane Composite Membrane Plate Straight Through Hole

Description

Composite Films Comprising Planar Nanoporous Oxide Ceramic Membranes and Multi-functional Filters Using the Same}

The present invention relates to a composite membrane useful for filtration, purification, purification, and dialysis, and a multifunctional filter using the same, wherein the plate-shaped metal is patterned into a predetermined pattern and then anodized to form a nanoporous oxide ceramic membrane and a metal support part. And improving the mechanical strength and adhesion to other structures of the anodized nanoporous oxide ceramic membrane by forming a composite membrane composed of metal bonds, and also adsorbing various catalysts, catalytic materials, or special materials on the anodized nanoporous oxide ceramic membrane. The present invention relates to a multifunctional filter using a composite membrane, which is intended to increase the filtration performance and efficiency, to provide multifunctionality, and to simplify and integrate a structure by stacking and fabricating a membrane prepared by coating a functional material with a plurality of uncoated membranes. .

Filters composed of conventional porous oxide ceramic membranes such as cordierite, mullite, alumina, zirconia, chamotte, and titanium alumina manufactured by conventional methods such as slip casting based on sol-gel method have bent pores of various sizes. Although the porosity is relatively low and the blockage phenomenon occurs severely, it is easy to disinfect and has excellent durability, and is widely used as a water treatment filter or food and beverage purification filter such as an ultrafilter or a nanofilter.

And exhaustion in harsh environments with high temperatures, strong acids, and strong bases, provided that the chemical stability in high temperature reactive gas atmospheres withstands thermal and mechanical shock resistance when backwashed by low temperature pulsed gases, and thermal expansion. Used as a combustion gas filter

In addition, the oxide ceramic filter includes oxide ceramics such as TiO ₂ , V ₂ O ₅ , WO ₃ , SnO ₂ , ZnO, Cr ₂ O ₃ , MoO ₃ , Co ₃ O ₄ , Fe ₂ O ₃ , Mn ₃ O ₄ , Pt, Excellent adhesion of metal adsorption / catalyst materials or other polymer adsorption materials such as Pd, Au, Ag, Ir, and other polymers to provide functionality easily, volatile organic compound gases (VOC), NO _x , SO _x by adsorption or catalytic oxidation Can be used for the filtration and separation of environmentally harmful gases such as dioxins, CO ₂ , and CO, and for filtering various bacteria and viruses.

However, these porous oxide ceramics have disadvantages such as difficulty in forming pores of uniform size, limitation in increasing porosity, heavy installation, high initial installation cost, and low elasticity, and high risk of breakage due to mechanical impact. Its use is limited. Moreover, the conventional oxide ceramic membrane has a disadvantage in that small particles are broken due to low sintering density due to its low heat treatment temperature, which is not suitable for ultra-high purity gas purification filter in high electronic or precision machinery industries. .

Unlike conventional porous ceramic membranes manufactured by conventional methods, anodized nanoporous oxide ceramic membranes such as aluminum oxide membranes and titanium oxide membranes prepared by anodization have a high porosity, very high filtration efficiency, and thin membranes. The pressure drop in the front and rear is not large, and it has a through-hole pore through a uniform straight line, so that harmful particles having a smaller size than the pore can be efficiently and effectively filtered without large blockage. .

Thus, the pore channels can be used for much longer than conventional membranes without the need for frequent cleaning. Moreover, the pore size is not only very uniform, but can be adjusted in the range of several nm to several hundred nm, and when the membrane is applied to a filter, the filtration selectivity of the membrane is very excellent.

The anodized nanoporous oxide ceramic membrane is an anodized aluminum or aluminum alloy to produce an alumina membrane. If one wants to anodize a titanium or titanium alloy, HF, KF, NaF, and H ₂ SO ₄ and HF, CrO ₃ and HF, (NH ₄ ) ₂ SO ₄ and NH ₄ F, (NH ₄ ) ₂ Any solution of SO ₄ and NaF is used as an electrolyte, and anodized by applying a voltage of 10 to 250 V corresponding to this electrolyte to obtain spontaneous alignment.

The anodized nanoporous alumina membrane, which is one of the anodized nanoporous oxide ceramic membranes, is hydrophilic in its surface and can greatly improve the flow rate of a fluid such as water, and can be used with excellent performance in water treatment. In addition, due to the excellent human compatibility, clogging is receiving a lot of attention in the field of life sciences, such as hemodialysis is a serious problem.

Since the melting point of the anodized nanoporous alumina membrane is 1000 ° C, the melting point can be used at temperatures up to 600 ° C, and can be used even at high temperatures up to 1000 ° C when heat-treated at high temperatures for phase transformation into crystals. This phase transformation is chemically very stable and can be used even in environments of strong bases and strong acids, and can be used for ultrafiltration, nanofilter filtration and reverse osmosis filtration, even in harsh environments of acid and base atmospheres under high temperatures.

In addition, anodized nanoporous titania membranes having straight through holes of different sizes have excellent chemical stability, and have a high melting point of 1870 DEG C, which can be used in very harsh alkali or acidic atmospheres at very high temperatures. The three crystalline phases of this oxide, anatase, rutile and brookite, are photocatalytic and decompose environmentally harmful gases such as VOC, NO _x and SO _x without depositing other catalysts on the surface or pores of the film. Can be used as a filter.

And the anodized nanoporous oxide ceramic membrane is similar to the conventional oxide ceramic membrane such as TiO ₂ , V ₂ O ₅ , WO ₃ , SnO ₂ , ZnO, Cr ₂ O ₃ , MoO ₃ , Co ₃ O ₄ , Fe ₂ O ₃ , Mn Excellent adhesion of oxide ceramics such as ₃ O ₄ and metal adsorption / catalyst materials such as Pt, Pd, Au, Ag, Ir, etc., and physical vapor deposition such as sputtering and evaporation, CVD, electrochemical deposition, or sol-gel By coating these materials using the same coating method as the wet method, functionality can be easily provided, and the filtration or separation of environmentally harmful gases such as VOC, NO _x , SO _x , dioxin, CO ₂ , CO, and various bacteria and Can be used as a filter for virus filtration.

Therefore, if the above-mentioned anodized nanoporous oxide ceramic membrane is replaced with the existing porous oxide ceramic membrane, it is expected that the performance, efficiency, and economics of the filter will be greatly improved, and its field of use will be greatly expanded. However, since the anodized nanoporous oxide ceramic film is also a ceramic film, brittleness is strong and brittle, and there is a possibility that a transition occurs due to the transition from metal to oxide, and thus it cannot be manufactured in a large size. There is a disadvantage that special technology is required for the assembly of.

The present invention applies the above-mentioned anodized nanoporous oxide ceramic membrane to a ceramic filter to produce a filter having high filtration efficiency, filtration selectivity, light weight, excellent mechanical properties, high thermal and mechanical impact resistance, and low cost. By patterning and anodizing a metal plate such as aluminum alloy, titanium or titanium alloy, the mechanical strength of the anodized nanoporous oxide ceramic membrane is increased by forming a composite film composed of the anodized nanoporous oxide ceramic membrane, the metal support portion and the metal bonding portion. It is an object of the present invention to provide a composite membrane comprising a plate anodized nanoporous oxide ceramic membrane that improves and facilitates bonding with adjacent structures.

In addition, the surface and pores of the composite membrane are coated with various adsorption substances, catalyst substances, and functional substances, each of which can adsorb and decompose environmentally harmful gases or bacteria, or impart special functionality. It is another object of the present invention to provide a multifunctional filter using a composite membrane including a high-performance multifunctional plate-shaped anodized nanoporous oxide ceramic membrane by combining and stacking one to many uncoated composite membranes to form a single filter.

In order to achieve the above object, the present invention provides an anodized nanoporous oxide ceramic membrane having a nano-sized straight through hole formed by patterning a plate-like metal in a predetermined pattern and then anodizing the metal, and a metal support part and a metal bonding part. A composite membrane including a plate-shaped anodized nanoporous oxide ceramic membrane comprising a composite membrane made of a composite material and a multifunctional filter using the same are provided in the technical subject matter.

In addition, the plate-shaped metal may be aluminum, Cu and Mn, Si, Mg, Cr, Zn, Zr, Ti alloy and aluminum alloy containing up to four elements of one of the elements, titanium and Al and V, Mo, It is preferred that it is any one of a titanium alloy comprising up to four elements of one of Ga, Ge, Ta, Nb, Mn, Fe, Cr, Co, Ni, Cu, Si, C, O elements.

In addition, the anodized nanoporous oxide ceramic membrane has a nano-pores of 1 ~ 300 nm size, preferably in the thickness range of 20 ~ 500 ㎛, the composite material is preferably a round, square or a predetermined shape. Do.

In addition, the metal support portion preferably has a predetermined pattern or shape, which is relatively thicker than the thickness of the anodized nanoporous oxide ceramic film, in order to improve the mechanical strength of the composite film.

In addition, the metal coupling portion is preferably formed in a predetermined pattern or shape surrounding the edge of the composite membrane for mounting or installation of the composite membrane on the side wall of the filter housing.

In addition, the metal coupling portion is preferably formed in a predetermined pattern or shape for bonding with the neighboring composite film of the lower or upper layer, or the lower or upper wall of the housing.

In addition, the patterning is preferably performed by any one or two or more complex processing processes of lithography, mechanical cutting, polishing, scraping, welding and riveting.

Here, the anodized nanoporous oxide ceramic film is formed of TiO ₂ , V ₂ O ₅ , WO ₃ , SnO ₂ , ZnO, Cr ₂ O ₃ , MoO ₃ , Co ₃ O ₄ , Fe ₂ O _3, and Mn ₃ O ₄ . The coating method of any one of oxide ceramics, metal catalysts of Pt, Pd, Au, Ag and Ir or polymer functional materials by sputtering, evaporation, electrodeposition, spray and sol-gel method It is preferable to include a coated film.

The filter may be formed by stacking only the composite film alone, or the composite film coated with the metal catalyst material or the polymer functional material in a single or plural form, or by mixing and stacking a plurality of the two kinds of composite film. It is preferable that it is produced and formed.

In addition, the filter is a laminate of the composite membrane at a predetermined interval inside one housing, the pore size of the nanoporous membrane in the composite membrane to be laminated according to the axial direction of the housing becomes larger, smaller, or constant, or It is preferable that the larger, smaller, and constant are arranged in a mixed state.

In addition, the filter is preferably manufactured by laminating a single or a plurality of the composite film of different material types or different material types.

According to the above problem solving means, the present invention has a high porosity and high filtration efficiency compared to the ceramic membrane manufactured by the conventional method, and has a uniformly sized straight through hole, so that the filtration selectivity is high and the clogging phenomenon is often low. No need for cleaning, long service life, thin thickness, less pressure drop before and after the membrane, and cheaper anodized nanoporous oxide ceramic membrane made of composite membrane gives better mechanical properties, heat and mechanical impact resistance In addition, there is an effect of improving the bonding and connectivity with other structures, and also improves the applicability to other devices.

In addition, the present invention is coated with one or more of the composite membranes with various adsorption / catalyst / functional materials, and then mixed with one or more of the uncoated composite membranes and laminated with a new filter. High performance and versatility, which allows the separation and filtration of particles, water treatment, food and beverage and oil filters, adsorption and decomposition of various environmentally harmful gases and bacteria, filtration and separation of blood and proteins, and special functions This has the effect of providing a filter.

According to the present invention, a method for producing a composite membrane including an anodized nanoporous oxide ceramic membrane is characterized by patterning a plate metal and anodizing the plate metal to form a metal film made of a ceramic film, a metal support portion, and a metal bonding portion. To be converted to a well compromised composite membrane.

The plate-like metal is aluminum, Cu and Mn, Si, Mg, Cr, Zn, Zr, Ti and Li alloys containing one to four elements, titanium and Al and V, Mo, Ga, Cutting, cutting, rolling, etc. any one of titanium alloy ingots containing up to four elements of Ge, Ta, Nb, Mn, Fe, Cr, Co, Ni, Cu, Si, C, O elements It is made of a sheet of 1 mm to 50 μm in thickness using one or more processes of mechanical processing and heat treatment.

The plate metal is then subjected to lithography, mechanical cutting, polishing, drawing, scraping, welding and riveting, or a combination of two or more of them, so that after anodization, the plate metal will act as a filtration membrane. The pattern is made up of an oxide nanoporous oxide ceramic membrane, a metal support portion for improving the mechanical strength of the entire composite membrane, and a metal coupling portion for connection and bonding with neighboring structures or filter housings.

The metal support portion is configured to enhance the mechanical properties of the entire composite membrane, the thickness of which typically must be thicker than the anodized nanoporous oxide ceramic membrane, depending on the design specifications of the filter, such as the size of the material membrane and the required strength.

In addition, the metal coupling part is mainly configured to mount or install the composite membrane on the side wall of the filter housing, the thickness of which is to be thicker for a more secure mounting, and the side surface is threaded or the surface roughness for easier mounting. It can be processed to very even sides. In addition, the metal joining portion may be configured to greatly improve the structural strength by integrating the entire filter through bonding with a neighboring upper layer composite film and bonding with the lower wall or the upper wall of the housing. However, the details of this coupling configuration may vary depending on the use of the filter and the circumstances of use.

The metal support portion and the metal coupling portion are patterned in a predetermined pattern or shape, and a pattern for mounting and installing the composite membrane on the side wall of the filter housing is usually patterned along the edge of the composite membrane, the patterned portion The width and area of the membrane depend on the size of the composite membrane and the design specifications of the filter.

It is usually preferred that the thickness of each part is the thickest in the order of the joining part for connection to the bottom under the housing, followed by the joining part for the mounting on the side wall of the housing, the intermembrane joining part and the support part.

The relative position of the anodized nanoporous oxide ceramic membrane relative to each support or bond may be located at the center, top, or bottom of each support or bond thickness. Depends on the environment

The patterned plate-shaped metal is selected and used according to the type of the metal and the space distance of the anodized nanoporous oxide ceramic membrane to be manufactured, and the pores in the selected electrolyte are spontaneously and closely aligned. Select and apply voltage from 10 to 250V.

Apparatus for producing the anodized nanoporous oxide ceramic film is well known, the matter that needs attention is to select a plate-shaped metal mesh (mesh) cathode to be placed in parallel with the metal plate as the anode to distribute the electric field between the anode and the cathode Should be uniform. In order to absorb heat generated during the anodization process, one side wall of the plate-shaped metal must maintain intimate thermal contact with the heat absorber so that the anodization proceeds in a steady state, and the heat absorber must have excellent heat absorption ability. For uniform electrochemical reactions, the electrolyte should be stirred to maintain a constant concentration throughout. Another layer of metal will be needed to protect the surface of the electrode and the heat absorber from excessive anodization beyond one surface of the plate metal. Here, process variables for anodization, such as applied voltage, electrolyte type and anodization temperature, will basically change depending on the kind of anodization to be performed, the space distance, and the degree of pore (cell) arrangement. Of course, the airspace distance depends primarily on the applied voltage after the electrolyte has been selected, and secondly on current and temperature.

The support portion may or may not or may not be anodized, but when anodized, the oxide film coating will tolerate harsh environments better. However, the bonding portion may be coated with a coating before anodization so as not to be anodized, and then peeling off the coating after anodization to make bonding with neighboring structures easier and more robust.

On the other hand, the thickness of the anodized nanoporous oxide ceramic membrane is better in terms of mechanical strength, but thinner in consideration of filtration performance. Preference is given to thicknesses of less than approximately 200 μm. In terms of mechanical strength, in the through-hole membrane, 100 to 200 µm is suitable. For this, when using the hard anodization method, the thickness can be sufficiently made in about 10 hours. However, if mild anodization is used, it should be anodized for 2 to 5 days. However, due to poor mechanical properties, a thickness thinner than 20 μm should be avoided. Special care is required to handle films thinner than 20 μm.

The thickness of the anodized nanoporous oxide ceramic film depends on the anodization time. After anodizing to a certain internal depth for a certain time, coating the support and the bond portion to prevent etching, and then using an acidic solution such as a mixed solution of CuCl ₂ and HCl to remove the remaining metal matrix without anodization. By removing the oxide barrier layer with an acid solution such as H ₃ PO ₄ , the thickness of the anodized nanoporous oxide ceramic membrane with straight through holes is determined. Alternatively, there is a method of producing an anodized nanoporous oxide ceramic film without an additional etching process by anodizing a metal already patterned to an appropriate thickness until a straight through hole is formed. Thereafter, the pore size may be increased by additionally treating the acid solution such as H ₃ PO ₄ .

1 shows an example of a composite film structure manufactured by the above method. The entire composite membrane is circular, and the support 200, which serves as a support inside the circular anodized nanoporous oxide ceramic membrane 100, has a structure in which a checkerboard shape is crossed across the intersection. The coupling portion 310 for coupling with the membrane and the coupling portion for coupling with the lower wall or the upper wall of the housing are the intersection portions where the horizontal and vertical support portions 200 meet. The coupling portion 320 with the housing for mounting on the housing wall is shaped like a belt that runs along the edge of the circumference.

Filtration or separation of environmentally harmful gases such as VOC, NO _x , SO _x , dioxin, CO ₂ , CO, and various bacterial or virus filtration and separation to the composite membrane, or further improve specific surface area. In order to improve the performance and efficiency of the function, a plurality of the composite film prepared above, Al ₂ O ₃ , TiO ₂ , V ₂ O ₅ , WO ₃ , SnO ₂ , ZnO, Cr ₂ O ₃ , MoO ₃ , Sputtering, evaporation, CVD, electro-deposition, spraying of oxide ceramics such as Co ₃ O ₄ , Fe ₂ O ₃ , Mn ₃ O ₄ , metal catalyst materials such as Pt, Pd, Au, Ag, Ir, or polymer functional materials Coating was carried out using any one of coating methods such as sol-gel method. The coated material also preferably has a thin porous layer or nanoparticle shape for very improved reactivity through its large specific surface area. Occasionally, hydrothermal treatment was performed to drastically reduce the pore size of the composite membrane at the local part of the pore channel.

One or more composite membranes were coated with a layer of hydrophilic polymer such as polyethylene glycol monomer to reduce adsorption to membranes of species such as protein or plasma albumin. In addition, natural polysaccharide or chitosan was coated to give various enzyme detection functions.

In order to manufacture a multifunctional filter using the uncoated or coated composite membrane, one or more membrane groups were stacked as follows, and the number or arrangement order of the membrane groups may vary depending on the purpose. At this time, one membrane group is composed of one or more membranes, the number of which varies depending on the role of the membrane, the design specification of the final filter, and the environment of use.

First, the filter group in the bottom layer is preferably a particle filter for removing harmful particles contained in the fluid sucked into the filter. The membrane group is a stack of several uncoated composite membranes. The larger the membrane, the smaller its pore diameter, allowing smaller and smaller particles to filter as the fluid flows over the filter.

The next filter group is a virus or pathogen membrane group, and it is preferable to use a composite membrane coated with hydrophilic polymer materials in order to improve its filtration efficiency and prevent adsorption of other substances. When the biofilm group is used together with the particle filter, it is preferable to arrange the membranes according to the pore diameter and the functionality.

In addition, a group of membranes for filtering or separating environmentally harmful gases such as VOC, NO _x , SO _x , dioxin, CO ₂ , CO, etc., and a plurality of composite membranes include TiO ₂ , V ₂ O ₅ , WO ₃ , SnO ₂ , ZnO, Coating one or more oxide ceramic materials such as Cr ₂ O ₃ , MoO ₃ , Co ₃ O ₄ , Fe ₂ O ₃ , Mn ₃ O ₄ , or sometimes metal catalysts such as Pt, Pd, Au, Ag, Ir It is preferable to coat one or two or more materials together with the oxides. In addition, the membrane group can be further divided into membrane groups which are further subdivided according to the type of gas to be separated by filtration. Each catalyst is effective for removal of one or more gases. For example, in order to remove NOx together with dioxins, it is preferable to use a V ₂ O ₅ / TiO ₂ or TiO ₂ -V ₂ O ₅ -WO ₃ SCR catalyst.

2 shows an example of a composite membrane laminated by function in a multifunctional filter manufactured using the uncoated or coated composite membrane, wherein the bottom layer in the housing 400 is a pre-filter. Back to top Particle filters, VOC filters, virus filters, SOx filters, NOx filters, and CO2 filters are stacked in this order.

In Figure 3 (a) is a photograph of the anodized nanoporous oxide ceramic membrane of the composite membrane according to the present invention, (b) is a photograph after coating the various adsorption / catalyst / functional material on the composite membrane The figure shown. After coating various adsorption / catalyst / functional materials as shown, it was confirmed that the size of the through-hole 110 was further reduced.

1-an embodiment of a composite membrane according to the present invention.

2-an embodiment of a composite membrane laminated by function in a multifunctional filter using a composite membrane according to the present invention.

Figure 3-(a) a photo showing the anodized nanoporous oxide ceramic membrane of the composite membrane according to the present invention, (b) coating various adsorption / catalyst / functional material on the composite membrane of Figure 3-(a) Figure shows a picture after one.

<Description of Major Symbols Used in Drawings>

100: anodized nanoporous oxide ceramic membrane 110: straight through

200: support portion 300: coupling portion

310: coupling portion with the housing 320: coupling portion with the neighboring composite film

400: housing

Claims (12)

A plate-shaped anode comprising an anodized nanoporous oxide ceramic film having a nano-sized through-hole formed by patterning a plate-like metal in a predetermined pattern and then anodizing, and a metal support portion and a metal bonding portion. A composite membrane comprising an oxidized nanoporous oxide ceramic membrane. The composite membrane according to claim 1, wherein the plate-shaped metal is any one of aluminum, aluminum alloy, titanium and titanium alloy. The composite material of claim 1, wherein the anodized nanoporous oxide ceramic membrane has nanopores having a size of 1 to 300 nm and has a thickness in the range of 20 to 500 μm. membrane. 2. The composite membrane of claim 1, wherein the composite membrane has a circular, rectangular, or predetermined shape. The plate-shaped anodization according to claim 1, wherein the metal support portion has a predetermined pattern or shape, which is relatively thicker than the thickness of the anodized nanoporous oxide ceramic film, in order to improve the mechanical strength of the composite film. Composite membranes comprising nanoporous oxide ceramic membranes. The plate-shaped anodized nanoporous oxide ceramic according to claim 1, wherein the metal coupling portion is formed in a predetermined pattern or shape surrounding the edge of the composite membrane for mounting or installing the composite membrane on the side wall of the filter housing. Composite membrane comprising a membrane. The plate-shaped anodized nanoporous material according to claim 1, wherein the metal bonding portion is formed in a predetermined pattern or shape for bonding with a neighboring lower or upper layer composite film or a lower wall or upper wall of the housing. Composite membranes comprising oxide ceramic membranes. delete The method of claim 1, wherein the anodized nanoporous oxide ceramic membrane comprises TiO ₂ , V ₂ O ₅ , WO ₃ , SnO ₂ , ZnO, Cr ₂ O ₃ , MoO ₃ , Co ₃ O _4. And Fe ₂ O ₃ and Mn ₃ O ₄ , a composite membrane comprising a plate anodized nanoporous oxide ceramic membrane. A single or multiple layers of the composite film of claim 9 or the composite film coated with the metal catalyst material or polymer functional material, or a mixture of two or more of the two kinds of the composite films are formed. A multifunctional filter using a composite membrane comprising a plate-shaped anodized nanoporous oxide ceramic membrane. 11. The multifunctional filter using a composite membrane according to claim 10, wherein the filter comprises laminating the composite membrane at a predetermined interval inside one housing. delete

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