scholarly journals Efficient preparation of crack-free, low-density and transparent polymethylsilsesquioxane aerogels via ambient pressure drying and surface modification

RSC Advances ◽  
2018 ◽  
Vol 8 (32) ◽  
pp. 17967-17975 ◽  
Author(s):  
Tiemin Li ◽  
Ai Du ◽  
Ting Zhang ◽  
Wenhui Ding ◽  
Mingfang Liu ◽  
...  
Keyword(s):  
Surface Modification ◽  
Ambient Pressure ◽  
Ambient Pressure Drying ◽  
Low Density

A low-density (48 mg cm−3) polymethylsilsesquioxane aerogel was prepared by ambient pressure drying and surface modification.

Preparation of low-density porous silica thin films by ambient pressure drying

2004 ◽  
Author(s):  
Lanfang Yao ◽  
Jun Shen ◽  
Guangming Wu ◽  
Xingyuan Ni ◽  
Jue Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Ambient Pressure ◽  
Porous Silica ◽  
Ambient Pressure Drying ◽  
Low Density ◽  
Silica Thin Films

Synthesis of low shrinkage monolith alumina aerogels by surface modification and ambient pressure drying

2018 ◽  
Vol 13 (9) ◽  
pp. 1240-1244
Author(s):  
Chi Li ◽  
Zheng Gong ◽  
Likang Ding ◽  
Donglai Guo ◽  
Wenbin Hu
Keyword(s):  
Surface Modification ◽  
Ambient Pressure ◽  
Ambient Pressure Drying ◽  
Alumina Aerogels

A Novel Route for Preparation of Transparent and Superhydrophobic Silica Aerogels

2009 ◽  
Vol 1234 ◽  
Author(s):  
Guo-you Wu ◽  
Xuan Cheng ◽  
Yu-xi Yu ◽  
Ying Zhang
Keyword(s):  
Surface Modification ◽  
Ambient Pressure ◽  
Sol Gel ◽  
Three Dimensional ◽  
Silica Aerogels ◽  
Ambient Pressure Drying ◽  
Nanoporous Structure ◽  
Surface Areas ◽  
Superhydrophobic Silica ◽  
Dta Curve

AbstractSilica aerogels were synthesized via sol-gel processing followed by a two-step surface modification and ambient pressure drying, using methyltrimethoxysilane (MTMS) and trimethylchlorosilane (TMCS)/ethanol/n-hexane as surface modification agents. The transparent silica aerogels possessed the porosities, densities and specific surface areas in the range of 87.7–92.3%, 0.27–0.17 g·cm-3 and 852–1005 m2·g-1, respectively. The SEM and HRTEM analysis revealed the three-dimensional nanoporous structure of the silica aerogels. The presence of –CH3 functional groups on the surface of silica particles as indicated by the FTIR spectra was further confirmed by two visible exothermic peaks at 310 and 450–500 °C from the DTA curve. In addition, the silica aerogels were superhydrophobic with the contact angle as high as 160°.

Preparation of monolithic titania aerogels with high surface area by a sol–gel process combined surface modification

RSC Advances ◽  
2014 ◽  
Vol 4 (62) ◽  
pp. 32934-32940 ◽  
Author(s):  
Hui Yang ◽  
Wenjun Zhu ◽  
Sai Sun ◽  
Xingzhong Guo
Keyword(s):  
Surface Modification ◽  
Surface Area ◽  
Ambient Pressure ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Ambient Pressure Drying ◽  
Sol Gel Process

Monolithic titania (TiO2) aerogels with high surface area were successfully synthesized by the sol–gel process combined surface modification, followed by ambient pressure drying.

Preparation Of Low-Density Xerogels At Ambient Pressure For Low K Dielectrics

1995 ◽  
Vol 381 ◽  
Author(s):  
D. M. Smith ◽  
J. Anderson ◽  
C. C. Cho ◽  
G. P. Johnston ◽  
S. P. Jeng
Keyword(s):  
Dielectric Constant ◽  
Ambient Pressure ◽  
Supercritical Drying ◽  
Temperature Limit ◽  
Ambient Pressure Drying ◽  
Low Dielectric Constant ◽  
Low Density ◽  
Silica Xerogels ◽  
High Temperature Limit ◽  
Low Dielectric

AbstractLow density silica xerogels have many properties which suggest their use as a low dielectric constant material. Recent process improvements to control capillary pressure and strength by employing aging and pore chemistry modification, such that shrinkage is minimal during ambient pressure drying, have eliminated the need for supercritical drying. Although xerogels offer advantages for intermetal dielectric (IMD) applications because of their low dielectric constant (<2), high temperature limit, and compatibility with existing microelectronics precursors and processes, they suffer from unanswered questions. These include: 1) are all pores smaller than microelectronics features, 2) what are their mechanical properties (for processing and particle generation), and 3) what is their thermal stability. We have produced bulk xerogels under similar conditions to those used for films and studied the effect of density on the pore size distribution and bulk modulus.

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.

Characterization and comparison of uniform hydrophilic/hydrophobic transparent silica aerogel beads: skeleton strength and surface modification

RSC Advances ◽  
2015 ◽  
Vol 5 (68) ◽  
pp. 55579-55587 ◽  
Author(s):  
Sekai Zong ◽  
Wei Wei ◽  
Zhifeng Jiang ◽  
Zaoxue Yan ◽  
Jianjun Zhu ◽  
...  
Keyword(s):  
Surface Modification ◽  
Industrial Production ◽  
Silica Aerogel ◽  
Large Scale ◽  
Preparation Method ◽  
Ambient Pressure ◽  
Ambient Pressure Drying ◽  
Silica Beads

This preparation method of skeleton improvement of wet silica beads by ambient pressure drying is suitable for economic and large-scale industrial production of silica aerogel beads.

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