Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for preparing transparent silicon dioxide aerogel by co-precursor normal atmosphere drying

A co-precursor, atmospheric drying technology, applied in the field of aerogel, can solve the problems of limited practical applicability, consumption of a large amount of solvent, poor mechanical strength, etc., and achieve the effects of good hydrophobicity, uniform internal skeleton, and reduced production costs.

Inactive Publication Date: 2009-02-25
XIAMEN UNIV
View PDF4 Cites 70 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In 2007, Te-Yu Wei in Taiwan obtained bulk SiO with better properties through multi-step solvent exchange and surface modification using orthosilicate as a precursor. 2 Airgel, sample porosity 97%, density 0.07g / cm 3 , thermal conductivity 0.036W·(m·K) -1 , the preparation cycle of this method is long, the process is cumbersome, and consumes a large amount of solvent, which limits its practical applicability
Since 2006, South Korea's Sharad.D Bhagat has added a multifunctional surface modifier during the gel formation process, using water glass as a precursor to prepare SiO under an atmospheric pressure drying process 2 Airgel powder, sample specific surface area 473~776m 2 / g, density 0.1~0.309g / cm 3 , the preparation time of this method is short and the process is simple, but the obtained is non-transparent white powder with poor mechanical strength

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for preparing transparent silicon dioxide aerogel by co-precursor normal atmosphere drying
  • Method for preparing transparent silicon dioxide aerogel by co-precursor normal atmosphere drying
  • Method for preparing transparent silicon dioxide aerogel by co-precursor normal atmosphere drying

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] The molar ratio of raw materials is TEOS: anhydrous ethanol: MTMS: distilled water = 1:20:0.3:8, 11ml of TEOS and 36.5ml of anhydrous ethanol are mixed and added to the container to start stirring, and then 2ml of MTMS modifier is added. Continue stirring, slowly add 7.2ml of distilled water after 15min, add hydrochloric acid after stirring evenly after another 15min, adjust the pH value so that the pH value of the solution is about 2.0; after continuous stirring for 8h, slowly add a certain amount of ammonia to make the system final The pH value is around 8.0. Stop stirring after 10min, add SiO 2 The sol is allowed to stand for 24 hours until the sample gels. Then use the 10% volume concentration of MTES n-hexane solution for solvent exchange and aging, the aging temperature is 30 ℃, solvent exchange once every 2 days, exchange for 3 times; after solvent exchange, the sample is allowed to stand in the n-hexane solution To remove the MTES remaining on the surface, wash it o...

Embodiment 2

[0038] According to the molar ratio, TEOS: anhydrous ethanol: MTMS: water = 1:15:0.3:10, mix 11ml of TEOS and 27.4ml of anhydrous ethanol into the container and start stirring, then add 2ml of MTMS modifier, Continue to stir, slowly add 9ml of distilled water after 15min, add hydrochloric acid after stirring evenly after another 15min, adjust the pH of the solution to around 2; after continuous stirring for nearly 8h, slowly add a certain amount of ammonia to make the pH of the system finally 8~ Between 8.5. Stop stirring after 15min, add SiO 2 The sol is allowed to stand for 24 hours until the sample gels. Then use the 20% volume concentration of MTES n-hexane solution for solvent exchange and aging, the aging temperature is 60 ℃, solvent exchange once every 2 days, continuous exchange 3 times; then the sample is allowed to stand in the n-hexane solution for carrying out Wash, wash once every 2 days, wash 2 times.

[0039] Drying process: first heat the gel sample at 50°C for 6 h...

Embodiment 3

[0043] The molar ratio of raw materials is TEOS: anhydrous ethanol: MTMS: distilled water = 1:18:0.4:8, 11ml of TEOS and 29.5ml of anhydrous ethanol are mixed and added to the container to start stirring, and then 2.7ml of MTMS modifier is added After stirring for 15 minutes, slowly add 7.2ml of distilled water. After another 15 minutes, add hydrochloric acid and adjust the pH value so that the pH value of the solution is about 2.0. After stirring for 8 hours, slowly add a certain amount of ammonia catalyst to make the system The final pH is around 8.5. Stop stirring after 15min, add SiO 2 The sol is allowed to stand for 24 hours until the sample gels. Then, the solvent was exchanged with n-hexane solution and aged at room temperature. The solvent exchange was performed once every 2 days for 5 consecutive exchanges.

[0044] The drying process is as follows: first heat the gel sample at 50°C for 6 hours, then heat up to 65°C at a rate of 1°C / min, hold for 7 hours, then heat up to ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
densityaaaaaaaaaa
densityaaaaaaaaaa
boiling pointaaaaaaaaaa
Login to View More

Abstract

A method for gelating a co-precursor relates to an aerogel. The invention provides a method for preparing transparent silica aerogel by normal pressure drying through a co-precursor method. The method has the advantages of low cost, simple process, short production cycle, controllable reaction course and continuous production. Tetraethyl silicate and absolute ethyl alcohol are put into a container according to a proportion and stirred, and added with methyl triethoxysilane; added with water and stirred; added with hydrochloric acid to regulate the pH of the solution; added with ammonia water to regulate the pH of the system after stirring; the silica sol is kept stand still after stirring to obtain wet gel; the obtained wet gel is put into a normal hexane solution or a normal hexane solution containing the methyl triethoxysilane with volume concentration of 10%-50% for solvent exchange and aging, after being exchanged by the solution containing the methyl triethoxysilane agent, the gel is washed by the normal hexane solution to remove the methyl triethoxysilane remained on the surface of the sample, and the transparent silica aerogel is obtained by drying.

Description

Technical field [0001] The invention relates to an aerogel, in particular to a method for preparing a transparent silica aerogel by using a co-precursor method to dry under normal pressure. Background technique [0002] Silica (SiO 2 ) Aerogel is a nanoporous material with high specific surface area, high porosity, low density and low thermal conductivity. Its skeleton is a nanoporous spatial network structure. Based on the special properties of the material, SiO 2 Aerogels have very broad application prospects in the fields of optics, electricity, thermal insulation, environmental protection, catalysis, and chemical engineering. Especially SiO 2 The aerogel-based nanoporous composite material has very low thermal conductivity and is a new type of high-efficiency heat insulation material. Its nano network structure can effectively reduce the solid heat conduction of the material, and the nanoporous structure effectively inhibits gas molecules For the effect of heat conduction, by...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/14
Inventor 余煜玺吴国友程璇张颖涂慧彬
Owner XIAMEN UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com