KR20060112445A - Manufacturing method of metal fiber immobilized by photocatalyst.nanosilver - Google Patents

Abstract

A manufacturing method of metal fiber to which photocatalytic particles and nanosilver particles are immobilized so that the metal fiber is usefully used when removing volatile organic compounds and bacteria in wastewater or purified water treatment, or air purification is provided. A manufacturing method of metal fiber to which photocatalyst and nanosilver are immobilized comprises: a first step of dip coating or spray coating a metal fiber that is made of SUS304 stainless steel and has an outer diameter of 1 to 1,000 mum with a polycarbosilane solution, and drying and firing the polycarbosilane solution coated metal fiber; a second step of dip coating or spray coating the metal fiber of the first step with a photocatalytic solution, and drying the photocatalytic solution coated metal fiber; a third step of dip coating or spray coating the metal fiber of the second step with a nanosilver solution, and drying the nanosilver solution coated metal fiber; and a fourth step of drying the metal fiber of the second step or the third step at 50 to 250 deg.C for 4 to 200 deg.C so that photocatalyst and nanosilver are floated on the surface of the metal fiber, and firing the metal fiber at 400 deg.C for 4 hours or more.

Description

Manufacturing method of Metal fiber immobilized by photocatalystnanosilver

Figure 1. Manufacturing method of photocatalyst and silver nano immobilized metal fiber

Figure 2. Surface state of the metal fiber after the pretreatment coating of Examples 1,2,3 of the present invention

Figure 3. Surface state of the photocatalyst immobilized metal fiber of Examples 4, 5, 6 of the present invention

4. Surface state of the photocatalyst immobilized metal fiber of Example 7,8 of the present invention

5. Surface state of the photocatalyst silver nano immobilized metal fiber of Example 9 of the present invention

6. Surface state of metal fiber

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to metal fibers immobilized with photocatalysts and silver nanoparticles for environmental purification, such as water treatment or air treatment, and more particularly, to methods of treating organic compounds and bacteria in wastewater, water purification or air purification. The present invention relates to a metal fiber obtained by immobilizing photocatalyst particles and silver nanoparticles on a metal fiber, and a method of manufacturing the same.

Generally, sedimentation method, activated carbon adsorption method, physicochemical treatment method, electrooxidation method, and biochemical treatment method are used to remove various contaminants present in water, but they are not completely decomposed or added chemicals. Due to this, there are disadvantages such as secondary pollution quality, high burden of facility cost and operation cost, and excessive land area.

In order to overcome these disadvantages, advanced oxidation treatment method is used to decompose and convert organic substances contained in water into harmless compounds such as carbon dioxide, water or hydrogen chloride by using OH radical which has more powerful oxidizing power than conventional oxidizing agents. have. Ultraviolet oxidation, ultraviolet ray, ozone or photocatalyst is used in the method. In particular, UV or ozone methods have been applied to remove bacteria and viruses harmful to the human body. However, UV light sterilization with ultraviolet rays at 254nm wavelength does not provide satisfactory efficiency with only one lamp. This is not only limited, but also harmful to humans due to residual ozone is a problem, and there are many difficulties in applying the site due to the enlargement of the system and the increase of the land area.

On the other hand, the photocatalyst method has the advantage that the organic material and bacteria are removed at the same time without any chemical additives as long as the ultraviolet lamp is an energy source, and the efficiency is high and the required area is small. TiO2, CdS, ZnO, SnO2, etc. generate electrons and holes when they receive light with a certain band gap energy, which can cause reduction and oxidation reactions, respectively. All of these belong to photocatalysts, but most of them are unstable in molecular structure, and thus, anatase type titanium dioxide (TiO2) photocatalysts with active electron and hole movements are widely used ("US Pat. No. 6,022,824"). When anatase-type titanium dioxide photocatalyst is irradiated with light energy with band interval of 3.0 ~ 3.2ev or more and 365nm or less, electrons are transferred from the consumer electronics to the conduction band, and the generated electrons and holes diffuse and move to the surface of the photocatalyst. The holes react with the adsorbed sorbents to produce OH radicals and O2 superoxide radicals, thereby decomposing the molecular bonds of the organic contaminants. That is, when the ultraviolet light energy (hv) is equal to or greater than the photocatalytic bond energy (Band gap energy), electrons are emitted from the valence band of the photocatalyst. The electron and electroreaction mechanism of the photocatalyst can generate OH radicals that can decompose the molecular structure of the contaminated organic compound. This recombination reaction of electrons and electrons has an effect of ultimately preventing electrons and holes from recombination by causing the generated holes and electrons to move in opposite directions in the space charge layer. This increases the possibility that the major and electron can participate in the catalytic reaction, such a phenomenon can be said to be an important factor in the heterogeneous photocatalytic reaction.

Looking at the prior art related to the photocatalytic water treatment system described above is as follows.

Publication No. 2001-0067693 "Air Float Type Photocatalytic Water Treatment Apparatus", Patent 2002-0092291 "Water Treatment Apparatus Using Oxidation of Titanium and Air," Patent 2003-0087801 "Water Treatment Apparatus and Water Treatment Method Using Ultrasonic Waves and Photocatalyst", Registration No. 10-0390652 "Method of Treating Wastewater Using Photocatalytic Reaction", Publication No. 10-0205443 "Wastewater Treatment System Using Photocatalyst", Registration No. 10-0392070 "Wastewater Treatment System Using Support Fixed by Sol-gel Method as Photocatalyst "Registration No. 10-0438668" Photocatalytic Reaction Water Treatment Apparatus ", Japanese Patent No. 2003-42725," Method for Manufacturing Immobilized Photocatalyst ", and the like.

Most of the prior art uses a photocatalyst on an inorganic carrier such as powder, bead, cylinder or honeycomb ceramic, glass, silica gel, zeolite, activated carbon, and the photocatalyst having a surface reaction due to its limited surface area. The efficiency is inevitably limited. In addition, most of the air gap is small, causing excessive pressure drop to reduce the throughput or increase the operating cost. In addition, the binding force between the carrier and the photocatalyst is weak, so that a long operation or a large flow rate may cause the photocatalyst to be detached from the carrier and discharged, or the strength of the carrier itself may be weak. In addition, due to the fixed type, proper conversion according to the reactor type is not easy, and the load is large, and thus there are many difficulties in installation and operation. On the other hand, in the area where ultraviolet rays do not reach the carrier, the purification effect by the photocatalyst does not occur, and there is a possibility that anaerobic fermentation may occur due to the lack of bactericidal power against biomass.

Materials other than inorganic materials are very difficult to use as carriers. For example, metals with relatively good mechanical properties or moldability cannot be used as carriers. If the photocatalyst and silver nano are immobilized on the metal surface, thermal corrosion may occur during immobilization. This is because galvanic corrosion occurs continuously during use, and the strength of the metal carrier is significantly weakened, and in particular, the adhesion stability of the photocatalyst and silver nanoparticles immobilized on the metal carrier is lowered, resulting in desorption of the photocatalyst in a short time.

Accordingly, the technical problem of the present invention is to provide an amorphous carrier capable of imparting strength and porosity and surface area, and providing ease of operation, by using a stainless steel metal carrier, and using an active surface area as a carrier. In order to increase the size of metal fiber outer diameter in the range of 1 ~ 1,000㎛, and direct coating of photocatalyst and silver nano to metal fiber, thermal corrosion and continuous galvanic corrosion occur, so pretreatment of the surface of metal fiber with polycarbosilane solution By coating, the metal surface is converted to inorganic surface to remove thermal corrosion and continuous galvanic corrosion generated during immobilization, and the photocatalyst is immobilized with strong bonding force on the metal fiber converted to inorganic surface, and sterilization can be performed even in the absence of UV light. In order to add the functionality that silver nano is further immobilized carrier To.

In order to achieve the above technical problem, the present invention provides an irregular meshed metal fiber having a true density of 1.0 g / cm 3 to 5.0 g / cm 3 in which photocatalyst and silver nano are fixed on a metal fiber surface having an outer diameter of 1 to 1,000 μm made of SUS304 stainless steel. It provides a manufacturing method, the metal fiber of the outer diameter of 1 ~ 1,000㎛ made of SUS304 stainless steel is as shown in the electron microscope picture of Figure 6.

In an embodiment of the present invention, the photocatalyst / silver nano immobilized metal fiber is preferably a photocatalyst content of 0.1 to 25 mg, silver nano content of 0.001 to 1.0 mg per 1 g of the metal fiber is immobilized.

In one embodiment of the present invention, the photocatalyst / silver nano-immobilized metal fiber manufacturing method,

(a) pre-treating a fibrous metal surface having an outer diameter of 1 to 1,000 μm made of SUS304 stainless steel to prevent corrosion and increase adhesion to the metal surface;

(b) preparing a photocatalyst solution of 0.5 to 15% for coating a photocatalyst content of 0.1 to 25 mg per gram of metal fiber to immobilize the photocatalyst on the metal fiber;

(c) immobilizing the silver nanoparticles on the metal fibers using a 0.05-1.5% silver nano solution for coating 0.001 to 1.0 mg of silver nanoparticles per gram of metal fiber;

(d) strengthening the bonding force between the surface of the metal fiber and the immobilization material (photocatalyst / silver nano) and aging the photocatalyst / silver nanoparticle on the surface of the coating layer;

(e) It is preferable to include forming a photocatalyst and silver nano immobilized metal fiber as needed.

Hereinafter, an immobilized metal fiber and a method of manufacturing the same according to the present invention will be described in detail.

(a) A pretreatment step must be carried out to fix the photocatalyst solution on the metal fiber or to fix the silver nano solution to prevent corrosion and to impart adhesion with a uniform distribution of photocatalyst and silver nano. A PCS solution is prepared by mixing 0.5% to 10% by weight of PCS (Polycarbosilane) based on 100% by weight of a natural oil solvent such as THF (Tetrahydrofurane) or orange oil and dipping the metal fibers therein or spraying them onto the surface of the metal fibers. It is dried for about 1 hour in a dry oven at 80 to 100 ° C. and then fired at 400 ° C. for more than 4 hours to prepare a pre-coated metal fiber.

(b) Ti-butoxide is mixed with PCS solution prepared in (a) to make a photocatalyst coating solution, and then dipping or spraying the pretreated metal fiber on the surface in the same manner as (a) and After drying for more than 1 hour in a dry oven to prepare a photocatalyst (metal fiber immobilized by photocatalyst) containing a photocatalyst having a size of 50 nm or less at a concentration of 0.1 to 25 mg photocatalyst content per 1 g of metal fiber.

(c) A silver nano solution was prepared by adding a surfactant to a solution in which silver nitrate was dissolved in water to generate silver ions, and then reduced with hydrazine to prepare a silver nano solution containing 20 to 50,000 ppm of silver nano particles having a size of 50 nm or less. The metal catalyst was immobilized by photocatalyst and nanosilver by dipping it onto the photocatalyst immobilized metal fiber before (b) or spraying it on the surface and drying it in a dry oven at 80 to 100 ° C. for at least 1 hour. ). If the function of the photocatalyst is not necessary, the pretreated metal fiber of (a) is dipping into the silver nano solution or sprayed on the surface and dried in a dry oven at 80-100 ° C for at least 1 hour to fix the silver nano metal (metal). fiber immobilized by photocatalyst).

(d) the three immobilizations prepared in (b) and (c), respectively, by strengthening the bonding force between the photocatalyst and the metal surface, silver nano and the metal surface, or the photocatalyst and silver nano and the metal surface, and by floating the coating layer photocatalyst or silver nanoparticle on the surface. The dried metal fibers were dried at 80 ° C. to 100 ° C. for at least 6 hours in a wet drying furnace to float photocatalysts or silver nanoparticles on the surface, and fired at 400 ° C. for 4 hours in a furnace for strong adhesion to metal surfaces. The wet drying conditions are adjusted so that the growth direction of the titanium dioxide or silver nanocrystals can be directed from the inside of the coating layer to the outside (surface), thereby significantly reducing the internal stress between the metal fibers and the crystals, thereby bonding the metal fibers with the coating layer. In addition to being strong, most photocatalysts or silver nanoparticles are present on the surface of the coating layer rather than inside the coating layer, thereby greatly increasing the activity.

(e) Photocatalyst and silver nano-manufactured manually or mechanically to meet the type and required pressure drop of the reactor to be applied after washing several times with water at room temperature to prevent excess nanoparticles or foreign substances floating on the metal surface after firing. Mold the immobilized metal fibers.

Next, the present invention will be described in more detail by way of examples.

Example. 1: Evaluation of coating surface according to polycarbosilane content

In immobilizing the photocatalyst and silver nano as shown in (a) above, 100% by weight of THF (Tetrahydrofurane) solvent is coated with 0.05% by weight of a mixed solution of PCS (Polycarbosilane; Nippon Carbon Co., Ltd.) during the pretreatment step, and the metal fiber is coated thereon. Dipping or spraying onto metal fiber surface It can be dried for about 1 hour in a dry oven at 80 to 100 ℃ and then fired for 4 hours in a furnace at 400 ℃.

Example. 2: Evaluation of coating surface according to polycarbosilane content

In immobilizing the photocatalyst and silver nano as described in (a) above, 100% by weight of a THF (Tetrahydrofurane) solvent is coated with 0.1% by weight of a mixed solution of PCS (Polycarbosilane; Nippon Carbon Co., Ltd.) during the pretreatment step, and metal fibers are coated thereon. Dipping or spraying on metal fiber surface It can be dried for about 1 hour in a dry oven at 80 to 100 ℃ and then fired for 4 hours in a furnace at 400 ℃.

Example. 3: Evaluation of coating surface according to polycarbosilane content

In immobilizing the photocatalyst and silver nano as shown in (a) above, 100% by weight of THF (Tetrahydrofurane) solvent is coated with PCS (Polycarbosilane; Nippon Carbon Co., Ltd.) with a 10% by weight mixed solution, and the metal fibers are coated on it. Dipping or spraying onto metal fiber surface It can be dried for about 1 hour in a dry oven at 80 to 100 ℃ and then fired for 4 hours in a furnace at 400 ℃.

Example. 4: surface coating according to the addition amount of titanium butoxide and polycarbosilane

Example above. Based on the pretreated metal fiber prepared as 2, the coating evaluation was performed by the following physical property control. THF (Tetrahydrofurane) was calculated as 100% by weight of total weight, and PCS (Polycarbosilane) was mixed with 0.1% by weight of total weight of Ti-butoxide in the solution by 2% by weight of total weight of the pretreated metal fiber. Or spray onto the surface of the metal fiber. After drying for about 1 hour in a dry oven at 80-100 ℃, the titanium butoxide contained in polycarbosilane was allowed to stand at 90 ℃ for 6 hours to float to the metal surface by surface injury. After firing, it can be fired for about 4 hours in a furnace at 400 ° C.

Example. 5: surface coating according to the addition amount of titanium butoxide and polycarbosilane

Example above. Based on the pretreated metal fiber prepared as 2, the coating evaluation was performed by the following physical property control. THF (Tetrahydrofurane) was calculated as 100% by weight of total weight, and PCS (Polycarbosilane) was mixed with 0.1% by weight of total weight of Ti-butoxide in the solution by 4% by weight of total weight of the pretreated metal fiber. Or spray onto the surface of the metal fiber. After drying for about 1 hour in a dry oven at 80 to 100 ° C, the titanium butoxide contained in polycarbosilane was left to stand at 90 ° C for 100 hours to float to the metal surface by surface injury. After firing, it can be fired for about 4 hours in a furnace at 400 ° C.

Example. 6: Surface coating according to the addition amount of titanium butoxide and polycarbosilane

Example above. Based on the pretreated metal fiber prepared as 2, the coating evaluation was performed by the following physical property control. THF (Tetrahydrofurane) is calculated as 100 parts by weight of total weight, and PCS (Polycarbosilane) is mixed with 0.1% by weight of total weight of Ti-butoxide in the solution by 50% by weight of total weight of the pretreated metal fiber. Or spray onto the surface of the metal fiber. After drying for about 1 hour in a dry oven at 80 to 100 ° C, the titanium butoxide contained in polycarbosilane was left to stand at 90 ° C for 100 hours to float to the metal surface by surface injury. After firing, it can be fired for about 4 hours in a furnace at 400 ° C.

Example. 7: Surface coating according to the addition amount of titanium isopropoxide and polycarbosilane

Example above. Based on the pretreated metal fiber prepared as 2, the coating evaluation was performed by the following physical property control. THF (Tetrahydrofurane) was calculated as 100 parts by weight of total weight, PCS (Polycarbosilane) was mixed with 0.1% by weight of total weight of Ti-Isopropoxide in solution by 4% by weight of total weight of the pretreated metal fiber. Or spray onto the surface of the metal fiber. After drying for about 1 hour in a dry oven at 80 to 100 ° C., the mixture was allowed to stand at 90 ° C. for 100 hours, whereby titanium butoxide contained in the polycarbosilane had a titanium oxide content on the surface of the metal fiber by phase transfer. After maximization, firing can be performed for about 4 hours in a furnace at 400 ° C.

Example. 8: Surface coating according to the addition amount of titanium ethoxide and polycarbosilane

Example above. Based on the pretreated metal fibers prepared as shown in Fig. 2, the coating properties were evaluated by the following physical property control. The total weight of the tetrahydrofurane (THF) was calculated as 100% by weight, and the total weight of PCS (Polycarbosilane) was 0.1% by weight. Ti-Ethoxide is mixed with 4 wt% of the total weight in the solution by dipping the pretreated metal fiber into it or sprayed onto the metal fiber surface. After drying for about 1 hour in a dry oven at 80 to 100 ° C., the mixture was allowed to stand at 90 ° C. for 100 hours, whereby titanium butoxide contained in the polycarbosilane had a titanium oxide content on the surface of the metal fiber by phase transfer. After reaching this maximum, it can be fired for about 4 hours in a furnace at 400 ° C.

Example. 9: surface coating according to the amount of nano silver added after coating of titanium butoxide and polycarbosilane

Example above. Based on the pretreated metal fibers prepared as shown in Fig. 2, the coating properties were evaluated by the following physical property control. The total weight of the tetrahydrofurane (THF) was calculated as 100% by weight, and the total weight of PCS (Polycarbosilane) was 0.1% by weight. Ti-Ethoxide is mixed with 4 wt% of the total weight in the solution by dipping the pretreated metal fiber into it or sprayed onto the metal fiber surface. After drying for about 1 hour in a dry oven at 80 to 100 ° C., the mixture was allowed to stand at 90 ° C. for 100 hours, whereby the titanium butoxide contained in the polycarbosilane had a titanium oxide content on the surface of the metal fiber by phase transfer. After maximizing, 1,000 ppm silver nanosol having a particle size of 50 nm or less, which is 100 wt% of total weight, is dipping or sprayed on the surface of the metal fiber to the metal fiber to which the photocatalyst calcined for about 4 hours in a furnace at 400 ° C. is immobilized. After drying for 1 hour in a dry oven at 80 to 100 ℃, it can be fired for about 4 hours in a furnace at 400 ℃.

Experimental Example One

The above embodiment. The surface conditions of the pretreated metal fibers of 1, 2, and 3 are as shown in Fig. 2. In 0.05 wt% of polycarbosilane in Example 1, the surface was unevenly coated. .3 At 0.1 wt% of polycarbosilane and 10 wt% of polycarbosilane, surface condition was found to be constant.

Experimental Example 2

The embodiment carried out above. The surface electron micrographs of Examples 4, 5, and 6 are the same as those of Fig. 3, and when observed with the surface electron micrographs of the metal fibers in the process of immobilizing the titanium butoxide. . In 4 and 5 it can be seen that the titanium butoxide is uniformly fixed, Example. In Figure 6, the overcoating of titanium butoxide caused the surface condition to be unbalanced, and it can be seen that surface abrasion occurred.

Experimental Example 3

The surface electron microscope measurement photographs of Examples 7 and 8 are the same as those of Fig. 4, and when observed with the surface electron microscope images of the metal fibers in the process of immobilizing titanium isopropoxide and titanium ethoxide. It can be seen that titanium isopropoxide and titanium ethoxide are uniformly immobilized.

Experimental Example 4

In Example 9, 1,000 ppm silver nanosol having a particle size of 50 nm or less was dipping or sprayed onto the surface of metal fiber, which was dried for 1 hour in a dry oven at 80 to 100 ° C, and then fired for 4 hours in a furnace at 400 ° C to observe the surface. As shown in FIG. 5, the silver particles may be uniformly coated.

Experimental Example 5

Example 9 Using a photocatalyst and a silver nano-fixed metal fiber in a process, 100 g of metal fiber was inserted into a 1 L photoreactor and orange G azodai (Sigma) was added at a concentration of 20 mg / L, and 20 W UV-A BLB (Sankyo Co., Ltd.) The degree of decomposition of orange G azodai was indicated as the first reaction rate constant using a lamp as a light source, and a sterilization evaluation was performed for general bacteria.The lamp was turned off and 99.9% due to the sterilization effect of silver nano. The bactericidal effect could be obtained and the bactericidal evaluation of general bacteria was shown in Table 1.

 Metal Fiber Input  UV-A BLB Lamp  Bactericidal power Resolution Dye decomposition rate constant (min ^-1 ) Dye decomposition half life (min)   100 g  ON  99.9%  0.03       23  OFF  99.9%  -  -

(1) The photocatalyst and silver nano immobilized metal fiber of the present invention has a much larger surface area than other conventional carriers because the diameter of the fiber is micrometer, and accordingly, the amount of photocatalyst and silver nano that can be immobilized per unit volume is increased. Excellent sterilization and antibacterial activity.

(2) The photocatalyst and silver nano immobilized metal fiber has a large porosity, so the pressure drop is relatively small. Therefore, the operation cost is low based on the same throughput, and the investment cost is small because the throughput can be processed on the same equipment scale.

(3) Photocatalyst and silver nano immobilized metal fiber has flexibility and can be easily converted according to the type of reactor and its load is easy to install, operate and exchange.

(4) Anaerobic fermentation by propagation of bacteria that can occur in the matt zone (the zone where ultraviolet rays are covered by other installations and thus no photocatalytic effect) can be suppressed by strong sterilization and antibacterial activity of silver nano.

(5) Compared with the conventional carrier, the metal fiber has not only a very strong strength but also the photocatalyst and silver nano are strongly immobilized and are not detached, thereby eliminating secondary pollution caused by particles falling from the metal fiber. The replacement and repair period is prolonged by extension, which is economically advantageous.

Claims (6)

  In the first step, metal fibers having an outer diameter of 1 to 1,000 μm made of SUS304 stainless steel are dried and baked after dip coating or spray coating with a polycarbon silane solution.   In the second step, the metal fiber of step 1 is dried after dip coating and spray coating with a photocatalyst solution,   In step 3, the metal fiber of step 2 is dried after dip coating and spray coating with silver nano solution,   In the fourth step, the photocatalyst and silver nanoparticles are dried at 400 ° C for at least 4 hours after the metal fibers of step 2 or 3 are dried at 50 to 250 ° C for 4 to 200 hours to float the photocatalyst and silver nanosurface on the surface. Method of manufacturing immobilized metal fiber   The photocatalyst and silver nano-immobilized metal according to claim 1, wherein the polycarbon silane solution uses 90 to 99.9 wt% of solvent and 0.1 to 10 wt% of polycarbosilane based on 100 wt% of the total weight. Fiber manufacturing method  The photocatalyst solution of claim 1, wherein the photocatalyst solution is based on 100% by weight of the total weight of titanium alkoxide selected from titanium butoxide, titanium isopropoxide, and titanium ethoxide; , A method for producing a photocatalyst / silver nano-immobilized metal fiber, characterized in that 0.1 to 10% by weight of polycarbosilane is used.  The photocatalyst / silver nano-immobilized metal according to claim 3, wherein the silver nano solution uses a silver nano solution dispersed in a solvent having a silver nano particle size of 50 nm or less and a silver nano particle concentration of 100 to 5,000 ppm. Fiber manufacturing method  The solvent according to claim 2, 3 or 4, wherein the solvent is selected from tetrahydrofuran, orange oil, vegetable natural oil, methyl ethyl ketone, isopropyl alcohol, methyl ethyl ketone, methanol and ethanol. Method for producing a metal catalyst immobilized photocatalyst, silver nano, characterized in that used by mixing The method for producing a photocatalyst / silver nano-immobilized metal fiber according to claim 4, wherein the photocatalyst / silver nano-immobilized metal fiber is dried for 80 to 100 hours at 90 to 100 ° C. for surface injury of the photocatalyst and silver nano.

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