KR20070114667A - Metal-coated aerogel of nanoporous materials and preparing method thereof - Google Patents

Abstract

An aerogel and a method for manufacturing the same are provided to improve adiabatic property, porosity, and transparency of the aerogel, by forming a gold or silver coated layer on a surface of a wet gel through chemisorption of thiol groups and gold or silver. A wet gel is prepared by a sol-gel process of aerogel precursor such as metal alkoxide or water glass. A surface of the wet gel is reformed with thiol groups by submerging the wet gel into a mixture solution of sulfur-containing compound and alcohol. A gold or silver coated layer is formed on the surface of the wet gel by submersing the surface-reformed wet gel in a gold or silver nanoparticle solution so that gold or silver is self assembled on the surface of the wet gel through chemisorption of thiol groups and gold or silver. The wet gel coated with the gold or silver coating layer is dried.

Description

Metal-Coated Aerogel of Nanoporous Material and Manufacturing Method Thereof {Metal-Coated Aerogel of Nanoporous Materials and Preparing Method Thereof}

The present invention relates to a metal-coated airgel which is a nanoporous material and a method for producing the same, and more particularly, to a metal-coated airgel by chemisorption with thiol groups on the surface of the airgel and a method for producing the same.

Aerogel is a nano-porous material prepared by drying the wet gel produced by the sol-gel reaction without shrinkage, and is known as the lightest solid developed by mankind. Aerogels are the next generation of new materials with unique physical properties such as very low thermal conductivity, high surface area, low density, low dielectric constant and good sound insulation due to the high porosity of more than 90%.

Thus, aerogels have significant potential applications in energy saving / storage ultralight thermal insulation materials, high power / high density nanoporous energy conversion materials, sound insulation materials, catalytic materials and very low dielectric materials. The exact market size of aerogel materials is not known at present, but enormous global market size is expected in terms of creating new applications as well as replacing existing markets.

[Table 1] Aerogel Industrial Applications

Field Applications Insulation Material -Transparent super insulation for glass window-Replacement of CFC-release polyurethane foam for refrigerator-Insulation by house, other super insulation energy -Supercapacitor Electrode-Li-ion Battery Electrode-Solar Pond Cover Environment -Photocatalyst-Catalyst for VOC / CH ₄ oxidation and NO _x decomposition-Capacitive deionization electrode-Gas / liquid separation filter / membrane Electric -Ultra low dielectric-Various types of electrodes for energy and environmental application-Transparent photo diode, microwave circuit, piezoceramic layer Etc -Chemical sensor, particle detection in high energy physics, sound insulation

Among the various application fields of the airgel described above, the first attempted commercialization research is an insulating material. Representative research in this field is the insulation material manufacturing technology by forming a composite with a binder to improve the brittleness of the airgel. In other words, a method of manufacturing a flexible airgel sheet by forming a composite of a fiber or a web and an airgel such as a nonwoven fabric is known (US 2002/0094426, US 5,789,075, WO96 / 27726, WO97 / 10188). Most of these methods involve impregnating a sol silica solution in a fiber or fibrous web, and then performing a gelation reaction to form an aerogel-fiber composite. The technology was commercialized in 2003 by Aspen Aerogels in the US, producing flexible aerogel sheets.

In addition to the use as a heat insulating material described above, airgel, a nanoporous material, is a highly potential material as a next-generation new material of high value. It is possible to carry drugs, biomolecules, phosphors, catalysts, fillers, etc. in the nanoporous structure of aerogels, so it is applicable to new materials in IT, BT, NT, and ET fields. Until now, many patents have been applied for manufacturing process and raw material development research for improving airgel price, research on improving brittleness of aerogel, research on hydrophobicity, etc., but research through granting film processability or electric conductivity through modification of airgel Is rarely reported.

Applicant of the present invention has been filed in the Republic of Korea Patent Application 2006-33754 for the surface-modified aerogel and the coating using the acrylic group prepared by the following Scheme 1. This invention is an invention in which a nanoporous airgel film is easily manufactured in addition to the possibility of application to a transparent heat insulating material, and the film processability is imparted to an airgel which has serious limitations in product processability due to brittleness.

Scheme 1

The airgel surface modified with the acrylic group is a photocurable airgel. Since the airgel is UV curable due to the acryl groups attached to the surface, the airgel surface-modified with the acrylic group alone or mixed with UV-curable acrylate It is possible to produce a transparent airgel coating having hardness and properties. The airgel-containing coating agent surface-modified with the acrylic group forms a coating film by a very fast curing reaction within a few seconds to several tens of seconds.

If the nanoporous airgel is provided with not only thin film processability but also electrical conductivity and antistatic property, it is expected that the material applicability will be further increased, but no patent has been reported.

As described above, the present inventors focused on the strong adsorption force of the thiol group and the metal during the study for modifying the properties of the airgel having excellent thermal insulation, porosity, and transparency, and thus, the object of the present invention is a metal-coated nanoporous material. It is to provide an airgel.

Another object of the present invention is to provide a method of manufacturing a metal-coated airgel.

According to the first aspect of the present invention,

A self-assembly by thiol groups on the airgel surface and chemisorbing of gold or silver provides an airgel coated with silver or gold on the airgel surface.

According to the second aspect of the present invention,

Forming a wet gel surface-modified with a thiol group by a sol-gelation process of an aerogel precursor which is a metal alkoxide compound or water glass and a sulfur-containing compound;

Immersing the wet gel surface-modified with a thiol group in a gold or silver nanoparticle solution to self-assemble gold or silver on the surface of the wet gel by chemical adsorption of thiol and gold or silver to form a gold or silver coating layer; And

Drying the wet gel in which the gold or silver coating layer is formed;

Provided is a method for preparing airgel coated with gold or silver comprising a.

According to the third aspect of the present invention,

Preparing a wet gel by a sol-gelation process of an aerogel precursor which is a metal alkoxide or water glass;

Modifying the surface of the wet gel with a thiol group by immersing the wet gel in a mixed solution of a sulfur-containing compound and an alcohol;

Immersing the wet gel surface-modified with a thiol group in a gold or silver nanoparticle solution to self-assemble gold or silver on the surface of the wet gel by chemical adsorption of thiol and gold or silver to form a gold or silver coating layer; And

Drying the wet gel in which the gold or silver coating layer is formed;

Provided is a method for preparing airgel coated with gold or silver comprising a.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Sulfur-containing compounds are known to adsorb very strongly with metals such as gold or silver, and use these properties to modify the surface of the aerogels with thiol groups and then to adsorb the gold or silver chemically on the aerogels modified with thiol groups. New metal-coated aerogels have been developed. The metal-coated aerogel of the present invention may be used as a conductive material, a catalyst, a carrier carrier, a light-transmitting insulating material, and an electronic information material as having a conductivity by metal and porosity, insulation, and transparency of the airgel.

In one embodiment of the present invention, an airgel coated with gold or silver is provided. Gold or silver coated aerogels according to the present invention are prepared by a self-assembly method by the combined adsorption of thiol groups and gold or silver on the surface of the wet gel. Meanwhile, the wet gel surface-modified with a thiol group may be prepared by pretreatment or aftertreatment. As described in detail below, the pretreatment method is a method of preparing a wet gel surface-treated (surface modified) using a thiol group using an airgel precursor and a sulfur-containing compound as a co-precursor. The post-treatment method is a method of preparing a wet gel using an airgel precursor and then treating (modifying) the surface of the wet gel with a thiol group.

Metal-coated aerogels not only have the characteristics of aerogels such as high specific surface area and nanoporous structure, but also have electrical conductivity and antistatic properties. The airgel itself is an insulator, but the present invention provides an airgel in which gold or silver particles are evenly coated on the surface by a chemisorption of thiol groups (-SH) with gold or silver on the airgel surface. Such aerogels coated with gold or silver particles are electrically conductive.

Hereinafter, the gold or silver coated airgel manufacturing method of the present invention will be described in detail.

The gold (Au) or silver (Ag) coated airgel of the present invention is formed by a self-assembly method by a chemisorption reaction of gold or silver with a thiol group (-SH) on the surface of the airgel. First, a wet gel having a thiol group is present. To form. Wet gels with thiol groups can be prepared by pretreatment and posttreatment. Aerogels are generally prepared by sol-gel processes and drying processes. The sol-gelation process can be performed by any suitable sol-gel technique known in the art [R.K. Colloid Chemistry of Silica and Silicates 1954, chapter 6; C.J. Brinker, G.W. Scherer, Sol-Gel Science, 1990, Chaps 2 and 3]. The drying step can also be carried out by any general process known in the art.

First, in forming a wet gel having a thiol group by a pretreatment method, the aerogel precursor and the sulfur-containing compound are reacted together with a co-precursor to form a wet gel surface-modified with a thiol group. Wet gels are formed through hydrolysis and condensation reactions.

As noted above, the sol and gelation processes can be performed by any method generally known in the art, and are not particularly limited thereby. For example, hydrolysis proceeds by mixing an airgel precursor, a thiol group-containing compound and water and adding an acid as a catalyst. Thereafter, as the condensation reaction proceeds by adding a base, a sol is formed at the beginning of the condensation reaction, and the condensation reaction proceeds and gels further as time passes. The sol-gelation process is generally carried out at about pH 2-9, taking into account the formation of the wet gel, preferably the pH of the hydrolysis reaction is about 2, the pH of the condensation reaction is about 8. When the pH of the reaction medium is lower than 2 or higher than 9, it is desirable from the viewpoint of efficiency and economics of producing an epoxy group-modified silica gel because the reaction is fast or difficult to control the formation of silica gel effectively. Not. The sol-gelation can be carried out in the presence of an acid or base catalyst, but more preferably using a base. At this time, the catalyst is not limited thereto, but as the acid catalyst, HCl, H ₂ SO ₄ , HF, etc., and as the base catalyst, NH ₄ OH may be preferably used.

In the pretreatment method, these sol and gelling processes are carried out in the presence of thiol group-containing compounds, so that the thiol groups are attached to the silica network inside and on the surface of the wet gel formed in the sol and gelling.

Water glass or metal alkoxide may be used as a precursor of the airgel. If water glass is used as the airgel precursor, a pretreatment step in the acid is required to remove the salt, which is common. As the metal alkoxide, those having 1 to 6 carbon atoms in each alkyl group, preferably 1 to 4 carbon atoms, may be used. Such compounds are not particularly limited thereto, but tetraethoxysilane (TEOS) and tetrameth Toxysilane (TMOS), tetra-n-propoxysilane, aluminum isopropoxide, aluminum-sec-butoxide, cerium isopropoxide, hafnium tert-butoxide, magnesium aluminum isopropoxide, yttrium isopropoxide At least one selected from the group consisting of cations, titanium isopropoxide and zirconium isopropoxide may be used alone or in combination. In particular, tetraethoxy silane (TEOS) comprising silane is the most preferred metal alkoxide.

The sulfur-containing compound is not particularly limited, but a compound having at least one selected from the group consisting of alkanethiol, aromatic thiols, dialkyl sulfides, diaromatic sulfides and dialkyldisulfides may be used. . Examples of the sulfur-containing compound is not limited thereto, but may be represented by the following structural formula.

Wherein R and R '' are each independently C1-C10 alkyl or C6-C20 aromaticalkyl, and R 'is a methyl, ethyl or propyl group.

The airgel precursor and the sulfur-containing compound are preferably mixed at a mole ratio of 9: 1 to 1: 9. When less than 1 mole of sulfur-containing compound is mixed with 9 moles of airgel precursor, there is not enough reaction site for chemisorption with gold or silver, and the airgel may not be sufficiently coated with gold or silver. When more than 9 moles of sulfur-containing compound is used per 1 mole of airgel precursor, the structure of the gel network is incomplete, resulting in loss of airgel's unique properties such as porosity, light transmittance and low density.

On the other hand, water may be used in a 4 to 10 molar ratio based on the mixture of the sulfur-containing compound and the airgel precursor, and the acid is added in a catalytic amount. When water is used at less than 4 molar ratios, it is not preferable in that the hydrolysis reaction rate is slow, and in the case of using more than 10 molar ratios, it is not preferable at the point of reducing the condensation reaction rate.

The thiol group-modified wet gel formation reaction may be reacted at a temperature lower than their boiling point in consideration of the boiling points of the reactants used to form the thiol group-modified wet gel. Although not limited by this, For example, it can react at 30-90 degreeC, Preferably it is 40-70 degreeC. The temperature below 30 ° C is not preferable in that the reaction time is long, and if it exceeds 90 ° C, it is not preferable in that it is difficult to control the structure of the silica gel. In addition, the wet gel formation reaction modified with a thiol group can be carried out for 2-24 hours. If the reaction time is less than 2 hours, the thiol group-modified wet gel may not be sufficiently formed, and if it exceeds 24 hours, undesirable side reactions may occur, which is not preferable.

In one embodiment, when tetraethoxysilane (TEOS) is used as the metal alkoxide and (3-mercaptopropyl) trimethoxysilane is used as the co-precursor as the sulfur-containing compound, a thiol group is obtained by a reaction as in Scheme 2 below. Wet gel is formed.

Scheme 2

On the other hand, the wet gel surface-modified with a thiol group can also be prepared by the post-treatment method as follows. In the aftertreatment method, the wet gel is formed from the airgel precursor by a method generally used in the art as described above. Wet gel refers to a state just before drying as it is immersed in the reaction solvent after hydrolysis, condensation reaction and aging by the reaction of the airgel precursor and water.

That is, except that the sulfur-containing compound is not used, as described in the pretreatment method, a catalyst is added to the aerogel precursor and water to proceed hydrolysis, and then a condensation reaction of the hydrolyzate proceeds to a "sol" state. Compound of is formed. At this time, the condensation reaction can be carried out in the presence of a base or an acid catalyst, it is more preferable to use a base catalyst. After the sol solution is gelled, it is aged for a sufficient time to prepare a wet gel. In this case, the metal alkoxide or water glass as described in the pretreatment may be used as the airgel precursor. Catalysts Also, those described in the pretreatment method can be used.

The wet gel forming step may be carried out under the same conditions as the pretreatment method for the formation of the wet gel in the pretreatment method, specifically, for example, at 30-90 ° C., preferably at 40-70 ° C. for 2 hours. It can be reacted for 24 hours.

Thereafter, the wet gel is immersed in a mixed solution of a sulfur-containing compound and an alcohol to treat (modify) the surface of the wet gel with a thiol group. The alcohol used as a solvent for the surface modification is not limited thereto, but an organic solvent having sufficient solubility of an aerogel and a sulfur-containing compound such as ethanol, acetone, THF, acrylonitrile or hexane may be used. In this case, the sulfur-containing compound and the alcohol may be mixed in various mixing ratios according to the solubility of the sample, and the like, but the mixing ratio is not particularly limited, for example, about 5-30% by weight of the sulfur-containing compound solution It is preferable to use. If it is less than 5% by weight, the amount of the sulfur-containing compound is insufficient for reforming the wet gel, and if it exceeds 30% by weight, it is already sufficiently modified so that the effect of increasing the modification is insufficient.

Sulfur-containing compounds may also be used which are described as being used in the above pretreatment. The reforming reaction of the wet gel with the sulfur-containing compound can be carried out at 30-90 ° C. The temperature below 30 ° C is not preferable in that the reaction time is long, and if it exceeds 90 ° C, it is not preferable in that it is difficult to control the structure of the silica gel. In addition, the reforming reaction can be carried out for 1 hour-3 days. If the reaction time is less than 1 hour, the wet gel is inefficient because the surface is not sufficiently modified with thiol groups and more than 3 days is sufficiently modified.

In one embodiment, when tetraethoxysilane (TEOS) is used as the metal alkoxide as a post-treatment method, and (3-mercaptopropyl) trimethoxysilane is used as the sulfur-containing compound, wetting with thiol groups is carried out by the reaction of Scheme 3 below. Gel is formed.

Scheme 3

In the case of forming the airgel surface-modified with thiol by the post-treatment method, since the gel cluster is formed only by the airgel precursor, for example, TEOS, it hardly affects the transparency of the produced airgel. In addition, the pretreatment method using a co-precursor forms a gel in the presence of a silane compound having a thiol group (for example, R-Si (OR ') ₃ (R: thiol group, R': alkyl group), Thiol groups that can be combined with gold or silver are present not only on the surface of the gel cluster but also on the inside, but the post-treatment method results in most of the thiol groups being present only on the surface of the gel cluster, so that the conversion efficiency to the thiol group is high, thus, more even and uniform. A gold or silver coating layer is formed on the airgel.

When the wet gel having a thiol group is immersed in a gold or silver nanoparticle solution, a coating is formed while a self-assembled layer is formed on the wet gel while forming a bond by chemisorption of sulfur (S) of the thiol group with Au or Ag. Proceed. The gold or silver coating layer on the surface of the airgel particles and the airgel monolith is formed by chemisorbing metal particles on the surface of the airgel as shown in Equations 4 and 5 below.

Schemes 4 and 5

As can be seen in Schemes 4 and 5, the -0H groups on the surface of the airgel particles and the monolith are substituted with -SH groups, and then fine gold or silver particles are chemisorbed to form a gold or silver coating layer.

The metal nanoparticle solution may be prepared by reducing a metal precursor, for example, KAuCl ₄ , AgNO ₃ , or the like, or using Au or Ag nanoparticles as it is.

Although not limited thereto, the concentration of the metal particles in the metal particle solution in consideration of the metal ion coating property of the wet gel surface is preferably 10 ^-3 mM to 10 M. If the concentration of the metal particles is less than 10 ^-3 mM, the amount of the metal to be coated may not be sufficient, and even if the concentration of the metal particles exceeds 10 M, since the metal layer is sufficiently formed on the surface of the aerogel, the chemical adsorption of the metal is no longer performed. It is inefficient because it is not increased.

As the solvent in the metal particle solution, any solvent capable of sufficiently dissolving the above-described metal compound and having no side effects in the chemisorption reaction of the wet gel and metal modified with a thiol group may be used, and the solvent is not particularly limited.

The metal coating layer forming conditions may vary depending on the thickness of the metal-coating to be formed on the surface of the airgel, and is not particularly limited. Thus, those skilled in the art can suitably adjust the temperature, time, etc. in forming the metal coating layer to form the desired metal-coating layer. For example, when it is desired to form a thick metal coating layer, the metal may be adsorbed for a longer period of time at a high temperature. In addition, the temperature varies depending on the solvent used, and the adsorption step may be performed at a temperature below the reflux temperature of the solvent, but is not limited thereto. can do. If the temperature is less than 30 ℃ reaction rate is too slow, if it exceeds 100 ℃ there is a problem that the metal is not uniformly coated on the gel surface.

The adsorption time may also vary depending on the adsorption temperature (e.g., the lower the metal adsorption temperature, the longer the adsorption time), but it is not particularly limited, for example, it can be adsorbed for 10 minutes to 24 hours. connect. If it is less than 10 minutes, the metal may not be sufficiently chemisorbed on the wet gel, and if it exceeds 24 hours, it is not preferable in terms of economics.

As described above, the metal is adsorbed onto the wet gel to form a metal (gold or silver) -coated wet gel. The metal-coated wet gel can be recovered and dried to obtain a metal-coated airgel. Drying may be carried out by any method generally known in the art, and the present invention is not limited thereto, and drying methods such as atmospheric pressure drying and supercritical drying may be used. In the case of atmospheric drying or supercritical drying, if necessary, the solvent may be replaced with a solvent effective for drying before drying.

In the case of applying atmospheric drying, first, the alcohol solvent used may be replaced with isopropyl alcohol, acetone, hexane or a mixed solution and dried at a temperature of about 50 ° C. or more. It may be dried at room temperature for several days or may be dried in a short time at a high temperature using an oven. In addition, when performing the supercritical drying, as known in the art, drying using carbon dioxide, it is preferable to perform at 30 ~ 40 ℃, 100 bar. Supercritical drying In addition, if necessary, the supercritical drying may be performed after solvent replacement with methanol or ethanol.

The metal of the present invention, specifically, gold or silver coated aerogel has a conductivity and a porosity, insulation and transparency of the aerogel by the metal can be used as a conductive material, a catalyst, a carrier carrier, a light-transmitting heat insulating material, an electronic information material .

Hereinafter, the present invention will be described through examples. In addition, the following Examples do not limit the present invention.

Example

Example 1 Preparation of Wet Gel Having a Thiol Group

(1) Pretreatment.

(3-mercapto propyl) trimethoxysilane and tetraethoxysilane were mixed at 1: 9 (molar ratio) and water was added to the mixture at a molar ratio of 6: 1. The initial acidity of the mixture was pH 5-6 immediately after mixing (ie, before hydrolysis and condensation). Hydrochloric acid was added thereto and stirred under the condition of pH 2 to carry out a hydrolysis reaction. Thereafter, ammonium hydroxide was added and adjusted to pH 8 to proceed with gelation to prepare a wet gel, and then matured at 50 ° C. for 24 hours to obtain a wet gel surface-modified with a thiol group. Aerogels can be produced in monolithic or granular form, and in the form of granules, after hydrolysis reaction, the solution is sprayed through a nozzle to form a granule, followed by gelation and aging. 　

(2) Post-treatment

224 g of TEOS and 108 g of water were mixed to prepare a silica airgel precursor. The initial acidity of the TEOS and water mixtures was pH 5-6 immediately after mixing (ie, before hydrolysis and condensation). Hydrochloric acid was added thereto and stirred under the condition of pH 2 to carry out a hydrolysis reaction. Thereafter, ammonium hydroxide was added to adjust the pH to 8 to prepare a wet gel. The gel was then matured at 50 ° C. for 24 hours to obtain a wet gel. Wet gel can be produced in monolithic or granular form, and in the form of granules, after hydrolysis reaction, the solution is sprayed through a nozzle to form a granule, followed by gelation and aging.

The wet gel surface was modified with a thiol group by soaking the wet gel sufficiently in a mixed solution of (3-mercapto propyl) trimethoxysilane (20 wt%) and ethanol mixed solution (80 wt%). Reaction conditions are 24 hours at 50 degreeC.

The FT-IR spectra of the pre-treated modified aerogel showed CH stretching peaks in the 2900-3000 cm ^-1 section by participating in the reaction of (3-mercapto-propyl) trimethoxysilane, and TEOS It can be seen that the intensity of the OH stretching peak (a broad peak near 3600 cm ⁻¹ ) is relatively reduced compared to the airgel synthesized using the bay. This result shows that the modification of the airgel was successful.

In addition, the thermogravimetric analyzer (TGA) was used to determine the substitution of the thiol group. As a result, the weight loss was found at around 400 ° C. at which the organic functional group was decomposed. Interestingly, the hydrophilicity of the gel surface was reduced while the airgel was modified with a thiol group, so much less weight loss was observed due to evaporation of water around 100 ° C. compared to the airgel made with TEOS.

Example 2 Gold or Silver Coating of Aerogel Surfaces

(1) Preparation of Gold (Au) Nanoparticle Solution

KAuCl ₄ (133.5 mg, Aldrich) was dissolved in 250 mL of water and then heated to 100 ° C. To this solution 1% sodium citrate (25 mL) was added with vigorous stirring. The solution was heated for 20 minutes to obtain an aqueous gold nanoparticle solution.

(2) Preparation of silver (Ag) nanoparticle solution

To AgNO ₃ (10 ⁻³ M, 100 mL) ice-chilled NaBH ₄ (2 * 10 ⁻³ M, 300 mL) was added slowly. At this time, the reaction solution was continued vigorously stirring to obtain a yellow nanoparticle solution.

(3) Formation of metal layer using self-assembly method

In each of the gold and silver solutions, the wet gel (particle or monolith) whose surface was modified by the pre- and post-treatment methods of Example 1 was immersed at room temperature for 1 hour. Meanwhile, sulfur (S) and Ag or Au of the wet gel thiol group form a self-assembly layer by chemisorption, and the Ag or Au metal is coated on the surface of the wet gel.

Example 3: Preparation of Gold and Silver Coated Airgel by Supercritical Drying

The solvent was replaced to remove the unreacted water contained in the wet gel, and then dried by a supercritical method. Solvent replacement was carried out by immersing the wet gel in ethanol for 24 hours at room temperature as a solvent.

Solvent-substituted wet gel was placed in an autoclave, the autoclave was purged with carbon dioxide and then heated to 35-40 ° C. The internal pressure of the autoclave was increased to about 1,500 psig during the heating. After maintaining this temperature and pressure for 1 to 2 hours, the pressure of the autoclave for 2 to 3 hours at a rate of 15 to 25 psi / min by venting with a pressure relief valve while maintaining above the supercritical temperature of carbon dioxide (31 ° C.) Reduced. When the autoclave pressure dropped below 100 psig, the autoclave heater was turned off and the remaining alcohol was discharged using nitrogen during cooling. By drying using a supercritical device as described above, aerogels coated with gold and silver, respectively, were obtained.

Gold or silver-coated airgel of the present invention has a conductivity by metal and porosity, heat insulation and transparency of the airgel can be used as a conductive material, a catalyst, a carrier carrier, a light-transmitting heat insulating material, an electronic information material. In addition, a uniform and even metal coating layer is formed on the surface of the wet gel by a self-assembly method by chemical adsorption of thiol groups and gold or silver.

Claims (10)

An airgel coated with silver or gold on the airgel surface by self-assembly by thiol and gold or silver chemisorption on the airgel surface. The method of claim 1 wherein the airgel is water glass or tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetra-n-propoxysilane, aluminum isopropoxide, aluminum-sec-butoxide, cerium iso At least one alkoxide compound selected from the group consisting of propoxide, hafnium tert-butoxide, magnesium aluminum isopropoxide, yttrium isopropoxide, titanium isopropoxide, and zirconium isopropoxide as an aerogel precursor Silver or gold coated aerogels, characterized in that. The airgel of claim 1, wherein the metal alkoxide compound is tetraethoxysilane. Forming a wet gel surface-modified with a thiol group by a sol-gelation process of an aerogel precursor which is a metal alkoxide compound or water glass and a sulfur-containing compound; Immersing the wet gel surface-modified with a thiol group in a gold or silver nanoparticle solution to self-assemble gold or silver on the surface of the wet gel by chemical adsorption of a thiol group and gold or silver to form a gold or silver coating layer; And Drying the wet gel in which the gold or silver coating layer is formed; Gold or silver coated airgel manufacturing method comprising a. Preparing a wet gel by a sol-gelation process of an aerogel precursor which is a metal alkoxide or water glass; Modifying the surface of the wet gel with a thiol group by immersing the wet gel in a mixed solution of a sulfur-containing compound and an alcohol; Immersing the wet gel surface-modified with a thiol group in a gold or silver nanoparticle solution to self-assemble gold or silver on the surface of the wet gel by chemical adsorption of thiol and gold or silver to form a gold or silver coating layer; And Drying the wet gel in which the gold or silver coating layer is formed; Gold or silver coated airgel manufacturing method comprising a. The metal alkoxide compound according to claim 4 or 5, wherein the metal alkoxide compound is tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetra-n-propoxysilane, aluminum isopropoxide, aluminum-sec-butoxide. At least one selected from the group consisting of cations, cerium isopropoxide, hafnium tert-butoxide, magnesium aluminum isopropoxide, yttrium isopropoxide, titanium isopropoxide, and zirconium isopropoxide. How to. 7. The method of claim 6, wherein the metal alkoxide compound is tetraethoxysilane. 6. The sulfur-containing compound of claim 4, wherein the sulfur-containing compound comprises at least one selected from the group consisting of alkanethiols, aromatic thiols, dialkyl sulfides, diaromatic sulfides and dialkyldisulfides. Characterized in that the compound. The method of claim 4, wherein the mixing ratio of the mixture of the airgel precursor, the sulfur-containing compound and the sulfur-containing compound is 9: 1 to 1: 9 molar ratio. The method of claim 4 or 5, wherein the drying step is a supercritical drying or atmospheric pressure drying after solvent substitution pretreatment.