Silica-aerogel-powders “jammed” polyimide aerogels with excellent hydrophobicity and conversion to ultra-light polyimide aerogel

RSC Advances ◽  
2016 ◽  
Vol 6 (63) ◽  
pp. 58268-58278 ◽  
Author(s):  
Shuai Wu ◽  
Ai Du ◽  
Youlai Xiang ◽  
Mingfang Liu ◽  
Tiemin Li ◽  
...  
Keyword(s):  
Silica Aerogel ◽  
Silica Aerogel Powders

In this paper, SAp play a role as the shrinkage inhibiter to fabricate the SAp “jammed” polyimide gels.

Fast Synthesis of Spherical Silica Aerogel Powders by Emulsion Polymerization from Water Glass

2018 ◽  
Vol 3 (4) ◽  
pp. 1257-1261 ◽  
Author(s):  
Kyoung-Jin Lee ◽  
Young H. Kim ◽  
Je K. Lee ◽  
Hae-Jin Hwang
Keyword(s):  
Emulsion Polymerization ◽  
Silica Aerogel ◽  
Water Glass ◽  
Spherical Silica ◽  
Fast Synthesis ◽  
Silica Aerogel Powders

scholarly journals Phase transfer agents facilitate the production of superinsulating silica aerogel powders by simultaneous hydrophobization and solvent- and ion-exchange

2020 ◽  
Vol 381 ◽  
pp. 122421 ◽  
Author(s):  
Shanyu Zhao ◽  
Ana Stojanovic ◽  
Emanuele Angelica ◽  
Olivier Emery ◽  
Daniel Rentsch ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Silica Aerogel ◽  
Phase Transfer ◽  
Silica Aerogel Powders ◽  
Transfer Agents

A fast synthesis of silica aerogel powders-based on water glass via ambient drying

2017 ◽  
Vol 82 (2) ◽  
pp. 594-601 ◽  
Author(s):  
Yuelei Pan ◽  
Song He ◽  
Xudong Cheng ◽  
Zhi Li ◽  
Congcong Li ◽  
...  
Keyword(s):  
Silica Aerogel ◽  
Water Glass ◽  
Ambient Drying ◽  
Fast Synthesis ◽  
Silica Aerogel Powders

Phase-separation induced synthesis of superhydrophobic silica aerogel powders and granules

2019 ◽  
Vol 279 ◽  
pp. 120971 ◽  
Author(s):  
Riyong Liu ◽  
Jin Wang ◽  
Yu Du ◽  
Jianhe Liao ◽  
Xuetong Zhang
Keyword(s):  
Phase Separation ◽  
Silica Aerogel ◽  
Superhydrophobic Silica ◽  
Silica Aerogel Powders

Thermal conductivity of IR-opacified silica aerogel powders between 10 K and 275 K

1995 ◽  
Vol 28 (3) ◽  
pp. 581-587 ◽  
Author(s):  
T Rettelbach ◽  
J Sauberlich ◽  
S Korder ◽  
J Fricke
Keyword(s):  
Thermal Conductivity ◽  
Silica Aerogel ◽  
Silica Aerogel Powders

Thermal conductivity of silica aerogel powders at temperatures from 10 to 275 K

1995 ◽  
Vol 186 ◽  
pp. 278-284 ◽  
Author(s):  
Th. Rettelbach ◽  
J. Säuberlich ◽  
S. Korder ◽  
J. Fricke
Keyword(s):  
Thermal Conductivity ◽  
Silica Aerogel ◽  
Silica Aerogel Powders

scholarly journals Thermal insulation and hydrophobization of wood impregnated with silica aerogel powder

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Hong Chen ◽  
Yutian Zhang ◽  
Tuhua Zhong ◽  
Zhihui Wu ◽  
Xianxu Zhan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Silica Aerogel ◽  
Untreated Wood ◽  
Surface Hydrophobicity ◽  
Vacuum Impregnation ◽  
Great Promise ◽  
Water Contact ◽  
Impregnated Wood ◽  
Silica Aerogel Powders

AbstractThe aim of the study was to develop a simple and cost-effective method to improve thermal insulation and hydrophobicity of wood. Herein, we attempted to use commercially available silica aerogel powders suspended in ethanol to treat the wood by a simple vacuum impregnation process. The effects of particle size (20 µm and 40 nm) of silica aerogels and the number of impregnation cycles (1, 3, and 5 cycles) were examined on the thermal conductivity and the surface hydrophobicity. The results showed that the thermal conductivity of silica aerogel-impregnated wood decreased by approximately 38%. The water contact angle of the impregnated wood increased up to the maximum values 153° with a comparison with 80° of the untreated wood, indicating effective hydrophobization after silica aerogel impregnation. The tensile properties of the impregnated wood were found slightly improved. The results indicate that the impregnation of silica aerogel powders in wood can be a facile and efficient approach to prepare wood with thermal insulation and hydrophobicity, which may hold great promise to be employed in manufacturing wood-based materials used in interior decoration and buildings.

Environmental microscopy of capillary stress-induced strain behavior in ambient-pressure aerogels

1996 ◽  
Vol 54 ◽  
pp. 850-851
Author(s):  
Sudeep M. Rao ◽  
Joshua Samuel ◽  
Sai S. Prakash ◽  
C. Jeffrey Brinker
Keyword(s):  
Silica Aerogel ◽  
Ambient Pressure ◽  
Drying Shrinkage ◽  
Pore Filling ◽  
Silica Network ◽  
Strain Behavior ◽  
Partially Saturated ◽  
Capillary Stress ◽  
Wetting Liquid ◽  
Aerogel Films

Ambient pressure silica aerogel thin films have recently been prepared by exploiting reversible drying shrinkage caused by derivatization of the internal gel surface. Aerogels have porosities of upto 99.9% and due to the small size of the pores (few nanometers), large capillary stresses are produced in gels that are partially saturated with a wetting liquid. As a result of these capillary stresses, the flexible silica network undergoes strain which has been observed using environmental microscopy. This technique allows variation of the equilibrium vapor pressure and temperature, and a simultaneous monitoring of the deformation of the unconstrained film thickness. We have observed >600% deformation during the pore-filling and pore-emptying cycles. In this presentation, we discuss the unique stress-strain behavior of these films.Ref.: Sai S. Prakash, C. Jeffrey Brinker, Alan J. Hurd & Sudeep M. Rao, "Silica aerogel films prepared at ambient pressure by using surface derivatization to induce reversible drying shrinkage", Nature. Vol. 374, 30 March, 1995, 439-443.

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