KR20210020701A - A manufacturing method of hydrophobic silica aerogel powder with surfactant applied, a composite foam having silica aerogel and composite foam using this - Google Patents

Abstract

The present invention relates to a method for manufacturing a silica aerogel powder in which the structure and shape of particles are controlled by using a surfactant, and a method for manufacturing a composite foam using the aerogel powder. The present invention can manufacture silica aerogel powder having excellent physical properties such as superhydrophobicity and high specific surface area in a stable and simple process under normal pressure. Also, by mixing the silica aerogel with a binder and other additives to manufacture a composite foam through microwaves, the composite foam can be used as an insulating material for heat insulation and non-combustible materials, and the like.

Description

A manufacturing method of hydrophobic silica aerogel powder with surfactant applied, a composite foam having silica aerogel and composite foam using the same, a manufacturing method of hydrophobic silica aerogel powder with surfactant applied, a composite foam having silica aerogel and composite foam using this }

The present invention relates to a method for preparing a hydrophobic silica airgel powder to which a surfactant is applied and a composite foam using the silica aerogel, and to a composite foam made therethrough.

Aerogel is made of silicon dioxide (SiO2) woven structure like a nonwoven fabric, but the space between the threads is filled with air. 1 cubic meter of silica airgel is the lightest among inorganic insulating materials at less than 100 kg, and is a material with a high specific surface area (specific surface area of 600 m2/g or more) with a porosity of 80 to 99% and a pore size in the range of 1 to 50 nm, It is a material with excellent super insulation and low dielectric properties.

Airgel has excellent properties such as heat insulation, sound absorption, fire resistance, hydrophobicity, and shock mitigation, so it can be widely used for buildings, industries, shipbuilding, aerospace, defense insulation, sound-absorbing materials, heat shields, etc. As it is superior to existing materials, it is attracting attention as a next-generation insulation material, but it is used in extremely limited applications due to its complicated manufacturing process and high manufacturing cost.

The substitution of the sol solvent contained in the wet gel during the atmospheric drying process during the production of airgel is a pretreatment step for surface modification.In order to minimize drying shrinkage by lowering the capillary force during drying, the surface tension is low, and a chemical reaction with the surface modifier occurs. This is a process of modifying the -OH group into a species that does not have condensation reactivity.

After replacing the sol solvent such as methanol in the wet gel with n-hexane, which does not react with the surface modifier, the -OH groups on the surface are converted to -CH ₃ groups by a silane coupling reaction using a silyation agent such as TMCS (trimethylchlorosilane). By modifying, irreversible shrinkage due to condensation reaction during drying can be suppressed, and the surface properties of the gel are changed from hydrophilic to hydrophobic.

Changes in surface properties to hydrophobicity due to surface modification can suppress/prevent deterioration of physical properties such as heat and electrical conductivity increase due to moisture, which can occur in applications such as insulation materials and low-dielectric thin films. Control is of great importance in the application of airgels.

The wet gel, which has been surface-modified after solvent replacement, shrinks due to the capillary force caused by the low surface tension of the replacement solvent upon drying, but the contraction that occurs at this time is a reversible contraction that does not accompany the condensation reaction of the terminal species. Therefore, as the heat treatment process proceeds, the capillary force due to the solvent is relaxed, and the network structure re-expands due to the thermal expansion of the gas inside the pores. This phenomenon is called the spring-back phenomenon, and it can be said to be a key commercial drying mechanism.

In the case of an aerogel, a network of nanoporous structures is formed by a sol-gel reaction, and it is very difficult to control a nano-sized pore structure because it undergoes structural transformation by condensation and aggregation reactions during the drying process. Therefore, the produced airgel has a wide range of pore size distributions, and thus has a wide range of properties at the same time rather than exhibiting uniform properties. The mechanical and thermal properties of the airgel can be improved through the control of the pore structure, size distribution, and arrangement, and reproducible synthesis of insulating materials is possible through the establishment of a manufacturing process of a uniform porous material.

Airgel is applied to high-temperature or low-temperature piping in the form of a blanket, but at present, airgel blankets are not produced in Korea and rely on imports, and their application is limited due to high prices. The Korea Institute of Energy Research also carried out technology development for the localization of airgel insulators and obtained a patent for the method of manufacturing silica airgel powder, but the combination with inorganic to add airgel powder as a composite for insulating material was mixed with an aqueous organic solvent. Due to the hydrophobicity of the airgel powder, it is not easy, and the production of a composite with a polymer system has a problem in that it is difficult to form a composite by maximizing the content of the airgel powder.

In addition, conventional aerogels are difficult to maintain surface properties, and there is also a problem in that it is difficult to cut the foam.

Patent Document 1: Republic of Korea Patent Publication No. 10-1155431 (Method of manufacturing silica airgel powder) Patent Document 2: Republic of Korea Patent Publication No. 10-1521793 (Method of manufacturing silica airgel powder with reduced manufacturing cost)

The present invention is to solve the above-described problems, and the technical problem to be solved by the present invention is to provide a method of manufacturing a stable silica airgel powder having superhydrophobicity in a simple process, and applying the same to a silica airgel composite foam. .

A method for producing a superhydrophobic silica airgel powder for achieving the above object includes the steps of generating a silica airgel due to a gelation reaction by a sol-gel reaction using a water glass solution, a catalyst, a surfactant, and an organic silane compound; Exchanging the solvent by adding an organic solvent to the airgel; Filtering the solution; Drying the hydrate recovered in the filtration step; A method for preparing a hydrophobic silica airgel to which a surfactant is applied, characterized in that it includes, as a means of solving the problem.

In addition, the composite foam manufacturing method includes the steps of mixing a superhydrophobic silica airgel powder, a microcapsule foam, a binder, and other additives; Foaming the mixture in a container having a predetermined shape through microwaves; A method for preparing a composite foam using a hydrophobic silica airgel, comprising: further drying the composite foam, as a means of solving the problem.

The manufacturing method of silica airgel powder according to the present invention is simple and stable in the process, and since the composite foam is manufactured using microwaves, it is stable and economical and has an effect of preventing environmental pollution.

In particular, for the synthesis of the mesoporous structure, the micelle structure of the surfactant must be created and the process of decomposing it at high temperature must be performed, and in this process, the properties of the hydrophobic aerogel whose surface has been modified should be maintained by using a hydrophobic silica aerogel. It acts as a very important factor in the manufacturing process, and in the present invention, it is possible to recover the ultra-insulating, ultra-porous airgel powder that can maintain the optimal pore structure while maintaining the surface characteristics.

In addition, in the present invention, since the microcapsule foam and a binder are mixed in the airgel and foamed using microwave to produce a composite foam, the powder is prevented from being blown out and can be used for various purposes such as insulation. There is an advantage. In particular, since the foam can be cut, it has excellent workability, and the airgel does not separate even when used for a long time.

In addition, the present invention uses inexpensive raw materials and can be manufactured by a simple process, thereby economically recovering silica airgel.

In addition, since the present invention can impart formability to the airgel, it can be made in the form of a foam block of a general insulation material, and through this, excellent insulation properties through low thermal conductivity through the nanopores of the airgel and micro and macropores of the foam foam. It can have a lighter product due to the low density of the airgel itself and the nature of the foam.

And, in the present invention, water repellency is imparted to the foam by applying a hydrophobic airgel. Therefore, the nanoporosity of the airgel is hygroscopic, so it does not absorb water, but has a property of evaporating moisture, so there is an effect that can be used in various ways.

1 is a photograph of the silica airgel powder recovered by the present invention.
Figure 2 is a photograph of a silica airgel composite foam.
Figure 3 is a flow chart showing in order the process of manufacturing the hydrophobic silica airgel powder according to the present invention.
Figure 4 is a flow chart showing in order the manufacturing process of the composite foam using the silica airgel according to the present invention.
5 is a particle shape (FE-SEM) of a silica airgel powder prepared according to the present invention.
6 is a result of FT-IR analysis of the silica airgel powder prepared according to the present invention

Hereinafter, with reference to the accompanying drawings for a method of manufacturing a hydrophobic silica airgel powder to which a surfactant is applied and a method of manufacturing a composite foam using a silica airgel according to the present invention, only parts necessary for understanding the technical configuration of the present invention will be described, It should be noted that descriptions of other parts will be omitted so as not to obscure the subject matter of the present invention.

The present invention can be broadly divided into two manufacturing methods, first to prepare a silica airgel powder, and to prepare a composite foam comprising the silica airgel powder thus produced.

Below, first, a process of manufacturing a silica airgel powder will be described.

In the step of producing the silica aerogel of the present invention, water glass (Na ₂ SiO ₃ , SiO ₂ 30wt%) is diluted to a concentration of 0.2 to 1.5 M and mixed for 30 minutes or more, and then an acidic solution having a concentration of 0.5 to 5.0 M is added to a silica sol. The first step of mixing by stirring in a volume ratio of 1:0.1 to 0.5 (V _{silica sol} : V _{acidic solution} ) is preceded. (S100) Preferably, an acidic solution of 3.0 to 4.0 M is used to compare 1 to silica sol. : It is preferable to stir and mix at a volume ratio of 0.2 to 0.3, and when mixing, the silica sol should not be gelled. The acidic solution is an organic acid such as hydrochloric acid, sulfuric acid, acetic acid, nitric acid, and the like, and at least one acidic solution may be used, but is not limited thereto.

In this case, a second step of adjusting the particle shape, specific surface area, and pore size of the silica aerogel by adding a surfactant to the silica sol is included. (S200) The surfactant is in a volume ratio of 1:0.005 to 0.01 compared to the silica sol. It is preferable to stir and mix, and it is more preferable to use it in a volume ratio of 1:0.007 or less. It is preferable to use a minimum amount of surfactant, and if not used, the shape of the silica particles cannot be controlled. The surfactant is anionic surfactant sodium fatty acid (RCOO ^- Na ⁺ ), monoalkyl sulfate (RO(CH ₂ CH ₂ O) _m SO ^3- ), polyoxyethylene sulfate (RO(CH ₂ CH ₂ O) _m SO ^3- M ⁺ ), alkylbenzene sulfonate (RR'CH ₂ CHC ₆ H ₄ SO ^3- M ⁺ ), noalkyl ginseng salt (ROPO(OH)O ^- M ⁺ ), monoalkyl as cationic surfactant trimethyl ammonium salt _{^{(RN + (CH 3) 3}} X -), dialkyl dimethyl ammonium salt _{^{(RR'N + (CH 3) 2}} X -), alkyl methyl benzyl ammonium salt _{^{(RN + (CH 2 PH)}} (CH 3) 2 X ^-), amphoteric surfactants include alkyl sulfonic Phoebe others _{^{(RR'R 〃 N + (CH 2}} ) nSO 3), an alkyl carboxy betaine _{(R (CH 3) 2 N} + CH 2 COO -), a non-ionic surfactant Phosphorus polyoxyethylene alkyl ether (RO(CH ₂ CH ₂ O) _m H), fatty acid diethanolamine (RCON(CH ₂ CH ₂ OH) ₂ ), alkyl monoglyceryl ether (ROCH ₂ CH(OH)CH ₂ OH) or the like may be used, but is not limited thereto.

Through the second step of adding such a surfactant, a hydrophobic airgel having a modified surface can be obtained.

Meanwhile, a third step of preparing a silica aerogel by adding an organic silane compound to the silica sol may be further included. (S300) The organic silane compound is preferably used in a volume ratio of 1: 0.05 to 0.2 compared to the silica sol, It is more preferable to use in a volume ratio of 1: 0.1 to 0.15. Examples of the organic silane compound include trimethylchlorisilane (TMCS), hexamethyldisilazane (HMDS), methyltrimethoxysilane (MTMS), trimethylehtoxysilane (TMES), and ethyltrie. Ethyltriethoxysilane, phenyltriethoxysilane, demethoxydimethylsilane (DMDMS), methoxytrimethylsilane (TMMS), and the like may be used, but are not limited thereto.

On the other hand, in the present invention, unlike the conventional silica airgel formation and the surface modification process separately performed, by performing the two processes simultaneously, a sufficient surface modification effect can be obtained and the process speed can be increased. In other words, the second and third steps above can be performed simultaneously. Of course, the above two steps can also be done in sequence.

Subsequently, the fourth step (S400) of _{replacing the solvent is a step of replacing moisture (H 2} O) present in the airgel with an organic solvent in the step of generating the silica airgel, and it can be said to be a step of completing the surface modification. have. As the non-polar organic solvent used in the above step, n-hexane, n-heptane, Xylene, Cyclohexane, Benzene, Toluene, Acetone, etc. may be used, and it is more preferable to use n-hexane or Acetone. The non-polar organic solvent is preferably used in a volume ratio of 1:0.3 to 1.5 compared to the silica airgel, and more preferably used in a volume ratio of 1: 0.3 to 0.7. When the volume ratio of the organic solvent is less than 0.3, complete solvent substitution does not occur and the density of the powder increases.

And a fifth step (S500) of filtering the silica airgel follows. The fifth step is a step of removing water, organic solvents, organic silane compounds, etc. remaining in the solution in which the silica airgel is produced. It is preferable to use equipment such as a centrifuge or a filter press.

Finally, the sixth step (S600) of drying the silica airgel is a step obtained by drying and powdering the silica airgel under atmospheric pressure. Drying is performed in two steps at a temperature of 50 to 200°C, and it is preferable to first dry for 1 to 4 hours at a temperature of 50 to 100°C, and then secondary dry at 200°C or less for 1 to 4 hours. The primary drying is more preferably dried at 60° C. for 1 hour and then dried at 150° C. for 2 hours.

Through these steps, a hydrophobic silica airgel powder to which a surfactant is applied is prepared. Next, a process of making a composite foam using hydrophobic silica airgel powder to which such surfactant is applied will be described.

First, the composite foam using the silica airgel powder prepared by the above-described method includes a silica airgel powder, a microcapsule foam and a binder, and an additive. So, first, a seventh step (S700) of mixing them is performed, which is a step of mixing and manufacturing raw materials for forming a foam, and each composition is arbitrarily set and mixed.

Here, the additive is a flame retardant, and various types of flame retardants may be applied. For example, melamine-based flame retardants are used to be less toxic than halogen-based, easier to handle, and hardly generate toxic gases during pyrolysis, so that they do not affect human health and the environment. As the melamine-based flame retardant, melamine, melamine cyanurate, melamine phosphate, melamine polyphosphate, melamine borate, and the like may be applied. In addition, phosphorus (P)-based flame retardants react with combustible substances during combustion to form a carbonaceous layer on the surface of the polymer. This carbonaceous film blocks oxygen required for combustion and exhibits a flame retardant effect. , Ammonium phosphate, ammonium polyphosphate, metal phosphinate, or melamine polyphosphate.

In addition, a dispersant may be used for dispersing the airgel. These dispersants are added for deagglomeration and stability maintenance of the airgel, and those generally used in the art may be used without limitation. For example, commercial products of dispersants include DISPER BYK-2001, DISPER BYK-2100, DISPER BYK-180, and DISPER BYK-102.

In the seventh step, it is preferable to use a mixer for more effective mixing. The binder used in the above step is vinyl acetate (EVA) based, polyvinyl alcohol (PVA) based, acryl based, acrylamide based, vinyl chloride (PVC) based, polyvinyl acetal based , Acrylic, saturated polyester, polyamide, polyethylene, natural rubber, silicone, or melamine, or a mixture of these may be used.

After mixing, an eighth step (S800) of foaming the mixture in a container having a certain shape is followed. In the eighth step, a container made of Teflon is manufactured, the foaming mixture is put into the container, and then foaming is performed using microwaves. Foaming can be produced by foaming the power of the microwave for 3 to 20 minutes at 5 to 20 KW. It is more preferable to foam for 5 minutes at 6 KW of microwave power. If the microwave power is very high or the foaming time is long, the foam may burn due to the high temperature, and shrinkage may occur after complete foaming.

Finally, a ninth step (S900) of additional drying follows. The ninth step is to remove moisture that may remain in the composite foam, and it is preferable to dry it at 80 to 120°C for 10 to 48 hours. It is more preferable to dry it at 100° C. for 24 hours.

Hereinafter, the present invention will be described in detail through the following examples, and the present invention is not necessarily limited only by the following examples.

First, an example in which a silica airgel powder is prepared will be described.

[Examples of manufacturing silica airgel powder]

(Example 1)

An industrial sodium silicate solution (manufacturer: Yeongil Hwaseong, No. 3, SiO ₂ 30.01% by weight) was diluted to prepare a 6.18% by weight solution, and the total amount of the solution was 38.47 mL, and the above solution was used.

11 mL of 5 M nitric acid solution was mixed with the silica solution and stirred for 2 to 3 minutes, and then 0.01 g of Span-80 surfactant was added thereto, followed by stirring for 2 to 3 minutes. Gelation did not proceed in this step.

Then, for the gelation reaction, 10 mL of hexamethyldisilazane (HMDZ), an organic silane compound, was added and stirred for an additional 2 minutes to proceed with a sol-gel reaction to generate a wet gel (P100), and the entire mixed solution was very It gelled in a short time.

Surface modification (P200) was performed by adding 50 mL of n-hexane to the wet gel and stirring for 2 hours. The surface-modified solution was subjected to pressure filtration to remove residual moisture, n-hexane, and organic silane compounds (P300).

The wet gel after filtration was put in a drying oven and first dried at 50° C. for 1 hour under atmospheric pressure, and then secondary dried (P400) at 150° C. for 2 hours to finally obtain a silica airgel powder.

(Example 2)

In order to confirm the effect of the kind of the organosilane compound used in the gelation reaction, as the organosilane compound of Example 1, instead of hexamethylsilazane (HMDS), dimethoxydimethylsilane (DMDMS), methyltrimethoxysilane (MTMS). ), methoxytrimethylsilane (TMMS), and trimethylchlorosilane (TMCS) were added to each of 10 mL to prepare a silica airgel powder under the same conditions as in Example 1.

(Example 3)

In order to check the effect of the amount of the organic silane compound (HMDZ) used in the gelation reaction, the silica airgel powder was used under the same conditions as in Example 1, except that the amount of the organic silane compound of Example 1 was changed and used. Was prepared.

(Example 4)

Silica airgel powder was prepared under the same conditions as in Example 1, except that the organic acid of Example 1 was changed and used in order to confirm the effect of the type of organic acid used in the gelation reaction.

(Comparative Example 1)

An industrial sodium silicate solution (manufacturer: Yeongil Hwaseong, No. 3, SiO ₂ 30.01% by weight) was diluted to prepare a 6.06% by weight solution, and a cation exchange resin was used in an ion exchange resin tower to remove the impurity sodium (Na). The silica sol was recovered by filling in and passing the water glass solution through a resin column to remove the sodium component.

A wet gel was synthesized by adding aqueous ammonia (3M) to the silica sol (500 mL) from which impurities were removed, and adjusting the pH to 5.1.

Isopropyl alcohol (IPA), n-hexane, and trimethylchlorosilane (TMCS) were sequentially mixed with the collected wet gel, followed by surface modification and solvent replacement at 50° C. for 3 hours.

After separating and recovering the wet gel, it was put in a drying oven and first dried at 50° C. for 1 hour under atmospheric pressure, and then secondarily dried at 150° C. for 2 hours to finally obtain a silica airgel powder.

(Comparative Example 2)

An industrial sodium silicate solution (manufacturer: Yeongil Hwaseong, No. 3, SiO ₂ 30.01 wt%) was diluted to prepare a 6.13 wt% solution.

A mixed solvent was prepared with ethanol equivalent to 2/3 and water equivalent to 1/1 based on the volume of the water glass solution. A wet gel was formed by adding a water glass solution to the mixed solvent. Unlike other examples, acid treatment was not performed.

After separating and recovering the wet gel, surface modification, solvent replacement, and drying were performed in the same manner as in Comparative Example 1 to finally obtain silica airgel powder.

For the silica airgel powders prepared by the methods of Examples 1 to 4 and Comparative Examples 1 and 2, the results of confirming the tap density, specific surface area, contact angle, and volume and size of micropores are shown in Table 1 below.

Manufacturing method Tap density
[g/mL] Specific surface area
[m ² /g] Average pore size
[nm] Pore volume
[mL/g] Contact angle
[°] Example 1 0.07 781 13.98 3.27 142 Example 2-1 0.19 548 20.13 2.39 142 Example 2-2 0.50 257 9.914 0.41 10 Example 2-3 0.42 314 12.20 0.62 107 Example 2-4 0.16 578 21.45 2.96 128 Example 3-1 0.12 684 14.05 3.24 141 Example 3-2 0.13 671 16.27 3.54 136 Example 3-3 0.28 598 15.23 2.98 129 Example 4-1 0.17 494 24.7 3.05 127 Example 4-2 0.16 586 25.84 3.79 125 Comparative Example 1 0.31 824 4.2 1.46 136 Comparative Example 2 0.05 324 5.4 0.05 138

As shown in Table 1 above, the silica airgel powder according to the present invention has a relatively large average pore size and pore volume, a specific surface area is improved through a surfactant, and a contact angle is improved through a surface modification process.

Next, an example in which a composite foam including silica airgel powder is prepared will be described.

[Examples of manufacturing composite foam]

(Example 5)

The silica airgel powder, binder, and other additives obtained in Example 1 are mixed by selecting a certain mixing ratio, and the mixed composition is introduced into a mold made of Teflon. Thereafter, the mold is introduced into a microwave to irradiate microwaves to foam. When foaming is complete, the mold is naturally cooled. The molded article foamed from the cooled mold is demolded. The demolded molded article is further dried at 100° C. for 8 hours.

(Example 6)

A silica airgel composite foam was prepared under the same conditions as in Example 5, except that the mixing ratio of Example 5 was changed.

(Comparative Example 3)

The mixture having the same composition as in Example 5 was heat-treated at 150° C. to 200° C. for 2 hours by pressing a mold mold, and then the heat-treated mold mode was cooled.

The molded body molded from the cooled mold mold was deserted.

(Comparative Example 4)

A silica airgel composite foam was prepared under the same conditions as in Comparative Example 3, except that the mixing ratio of Comparative Example 3 was changed. That is, in Comparative Example 3 and Comparative Example 4, the process of foaming by putting into a microwave was omitted.

The results of confirming the thermal conductivity, flexural strength, compressive strength, flame retardancy and water absorption for the silica airgel composite foams prepared by the method of Examples 5 to 4 are shown in Table 2 below.

Manufacturing method Thermal conductivity
[mW/m·K] Compressive strength
[N/cm ² ] Flexural strength
[N/cm ² ] Flexural failure load
[N] aGas hazard
[minute] Example 5 0.017 12 152 43 14.0 Example 6-1 0.019 12 140 38 9.2 Example 6-2 0.023 13 136 41 7.6 Example 6-3 0.025 13 124 32 4.3 Comparative Example 3 0.045 8 84 19 3.7 Comparative Example 4-1 0.050 7 55 15 3.5 Comparative Example 4-2 0.058 7 34 10 3.2 Comparative Example 4-3 0.042 8 59 13 3.0

As shown in the table above, it can be seen that the composite foam made in the embodiment according to the present invention is excellent in all areas of thermal conductivity, compressive strength, flexural strength, flexural failure load and gas hazard.

The present invention was able to recover a silica airgel powder having a nanoporous structure as confirmed by the above examples, and a composite foam having thermal insulation properties could be manufactured using the airgel powder.

As described above, in the method of manufacturing a silica airgel powder and a composite foam according to a preferred embodiment of the present invention, a silica airgel having a high porosity is recovered and the powder is used for the composite foam, thereby having high thermal insulation properties and compressive strength , It is possible to manufacture a heat insulating material in the form of improved absorption and gas harmfulness.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (15)

In the recovery method of silica airgel powder,
Generating a silica airgel by a sol-gel reaction using a water glass solution, a catalyst, a surfactant, and an organic silane compound;
Solvent exchange by adding a non-polar organic solvent to the wet gel;
Filtering the wet gel solution;
Drying the wet gel recovered in the filtration step;
Method of producing a silica airgel powder comprising a.
The method of claim 1,
The catalyst is an inorganic acid catalyst, and the concentration of the inorganic acid catalyst is 0.1 to 5 M, and the amount of the catalyst is 1:0.1 to 0.5 volume ratio to water glass.
The method of claim 1,
The organic silane compound is one of dimethoxydimethylsilane (DMDMS), methyltrimethoxysilane (MTMS), methoxytrimethylsilane (TMMS), trimethylchlorosilane (TMCS) instead of hexamethylsilazane (HMDS), or A method for producing a silica airgel powder, which is a mixture of at least two or more.
The method of claim 1,
The organic solvent is one of n-hexane, n-heptane, Xylene, Cyclohexane, Benzene, Toluene, and Acetone, or a mixture of at least two or more of these solutions.
The method of claim 4,
The step of exchanging the solvent is a method of producing a silica airgel powder that is performed in a temperature atmosphere between 50°C and 60°C.
The method of claim 1,
The drying step is a method of producing a silica airgel powder that is performed in an atmospheric pressure atmosphere at a temperature between 50°C and 70°C.
The method of claim 1,
In the sol-gel reaction to generate a silica airgel, a silica solution of 5.5 to 6.5% by weight is used, the concentration of the catalyst used is 1 to 5M, and any one of nitric acid, hydrochloric acid, sulfuric acid, acetic acid, or a mixture of these Method for producing airgel powder.
The method of claim 1,
In the sol-gel reaction to generate a silica aerogel, the amount of catalyst used is 1/0/1 to 0.5 volume ratio to the silica solution, and the amount of surfactant is 1/0.01 to 0.1% by weight compared to the silica solution, and the organic silane compound is silica A method of producing a silica airgel powder having a volume ratio of 1/0.2 to 0.5 relative to the solution.
In the method for producing a silica airgel composite foam,
After mixing silica aerogel, a binder, and an additive, injecting the mixture into a mold made of Teflon, foaming is performed using microwaves,
The silica airgel is
Generating a silica airgel by a sol-gel reaction using a water glass solution, a catalyst, a surfactant, and an organic silane compound;
Solvent exchange by adding a non-polar organic solvent to the wet gel;
Filtering the wet gel solution;
Drying the wet gel recovered in the filtration step;
Method for producing an airgel composite foam, characterized in that it is manufactured, including.
The method of claim 9,
The microcapsule foam has a diameter of 20 μm to 50 μm, and maximum foaming is performed at 150°C to 170°C.
The method of claim 9,
The binder is vinyl acetate (EVA), polyvinyl alcohol (PVA), acrylic, acrylamide, vinyl chloride (PVC), polyvinyl acetal, acrylic, saturated Any one of polyester, polyamide, polyethylene, natural rubber, silicone, or melamine, or a mixture of these foamed airgel composite foams.
The method of claim 9,
The method of manufacturing an airgel composite foam, characterized in that foaming is performed using microwaves in the foaming step.
The method of claim 12,
The method of manufacturing an airgel composite foam, characterized in that the material of the mold into which the composition is added is Teflon.
The method of claim 9,
In the sol-gel reaction to generate a silica aerogel, a silica solution of 5.5 to 6.5% by weight is used, the concentration of the catalyst used is 1 to 5M, and any one of nitric acid, hydrochloric acid, sulfuric acid, acetic acid, or a mixture thereof is used, The amount of catalyst used is 1/0/1 to 0.5 volume ratio to the silica solution, the amount of surfactant used is 1/0.01 to 0.1% by weight compared to the silica solution, and the organic silane compound is silica having a volume ratio of 1/0.2 to 0.5 to the silica solution. Method for producing an airgel composite foam.
A composite foam made by the manufacturing method of any one of claims 9 to 14.

Images