Low density and hydrophobic silica aerogels dried under ambient pressure using a new co-precursor method

2016 ◽  
Vol 452 ◽  
pp. 187-193 ◽  
Author(s):  
Ming Li ◽  
Hongyi Jiang ◽  
Dong Xu ◽  
Ou Hai ◽  
Wei Zheng
Keyword(s):  
Ambient Pressure ◽  
Silica Aerogels ◽  
Low Density ◽  
Precursor Method ◽  
Hydrophobic Silica

Highly flexible silica aerogels derived from methyltriethoxysilane and polydimethylsiloxane

2015 ◽  
Vol 39 (10) ◽  
pp. 7832-7838 ◽  
Author(s):  
Liang Zhong ◽  
Xiaohong Chen ◽  
Huaihe Song ◽  
Kang Guo ◽  
Zijun Hu
Keyword(s):  
Ambient Pressure ◽  
Silica Aerogels ◽  
Ambient Pressure Drying ◽  
Low Density ◽  
Rapid Synthesis ◽  
Hydrophobic Silica ◽  
Highly Hydrophobic

The rapid synthesis of low-density, highly hydrophobic silica aerogels was performedviaambient pressure drying.

Super Thermal Insulating SiO2 Cryogels Prepared by Vacuum Freeze Drying

2010 ◽  
Vol 105-106 ◽  
pp. 851-854 ◽  
Author(s):  
Li Fen Su ◽  
Lei Miao ◽  
Gang Xu ◽  
Sakae Tanemura
Keyword(s):  
Freeze Drying ◽  
Ambient Pressure ◽  
Supercritical Drying ◽  
Silica Aerogels ◽  
Base Catalysis ◽  
Low Density ◽  
Solvent Exchange ◽  
Acid Base ◽  
Thermal Insulating ◽  
Silica Precursor

Traditionally, silica aerogels with low thermal conductivity are prepared by supercritical drying, however, the process is expensive and hazardous due to it run in autoclaves. In order to overcome these disadvantages, a cheaper and safer process, drying at ambient pressure has been developed for decades, but tedious repetitive gel washing and solvent exchange steps are involved. Therefore, in the present study, a novel vacuum freeze-drying was utilized to prepare the super thermal insulating SiO2 cryogels. The wet gels were synthesized via acid-base catalysis using tetraethoxysilane (TEOS) as a silica precursor and ethanol as a solvent. After vacuum freeze drying, nanoporous SiO2 cryogels with low density in the range of 0.08-0.15 g/cm3 were obtained.

Hydrophobic and low density silica aerogels dried at ambient pressure using TEOS precursor

2009 ◽  
Vol 471 (1-2) ◽  
pp. 296-302 ◽  
Author(s):  
Jyoti L. Gurav ◽  
A. Venkateswara Rao ◽  
Uzma K.H. Bangi
Keyword(s):  
Ambient Pressure ◽  
Silica Aerogels ◽  
Low Density

Study on Preparation of Mesoporous Silica Aerogels with Low Density and High Properties via Ambient Pressure Drying

2010 ◽  
Vol 148-149 ◽  
pp. 1491-1496
Author(s):  
Gang Qiang Geng ◽  
Wei Tao Bi ◽  
Yu Zhang ◽  
Deng Ke Sun
Keyword(s):  
Mesoporous Silica ◽  
Ambient Pressure ◽  
Sol Gel ◽  
Silica Aerogels ◽  
Ambient Pressure Drying ◽  
Ethanol Solution ◽  
Low Density ◽  
Micro Structure ◽  
Gel Time

The SiO2 aerogels of low density was fabricated by ion exchange and sol-gel method on the basis of sodium silicate. The effect of pH, aging，addition of DCCA and annealed temperature on the gel time, aerogel density, porosity and the micro-structure was systemly studied. The results showed that when the pH is 5, aging was 30%Vol .of TEOS/ethanol solution ,the addition of DCCA was 1.5ml, the gel system was annealed at 50 for 84 h, 60 for 72h, the best quality of silica aerogels with low density (0.14g/cm3), higher specific surface(610.643 m2/g) and pore size of 20~40 nm can be obtained.

scholarly journals Study of the influence of various solvents on the properties of hydrophobic silica xerogels

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 129-130
Author(s):  
A. A. Kolmakova ◽  
◽  
A. E. Baranchikov ◽  
Keyword(s):  
Atmospheric Pressure ◽  
Three Dimensional ◽  
Silica Aerogels ◽  
Nanoporous Materials ◽  
Optimal Combination ◽  
Nanoporous Structure ◽  
Low Density ◽  
Silica Xerogels ◽  
Hydrophobic Silica ◽  
Alcohol Solvents

Silica aerogels are low-density inorganic aerogels with a three-dimensional nanoporous structure. Due to the inherent properties of nanoporous materials, the possibility of using silica airgel is of great interest in various fields. To simplify the process and reduce costs, the use of atmospheric pressure drying (APD) is promising, the resulting materials are called xerogels. Silica xerogels based on methyltrimethoxysilane were synthesized using various alcohol solvents. The optimal combination of properties is possessed by a sample obtained using methanol as a solvent. The wetting angle of all xerogels was 158°, which characterizes the resulting material as superhydrophobic.

Sign in / Sign up

Export Citation Format

Share Document