Effect of heat treatment on hydrophobic silica aerogel

He, Song; Huang, Yajun; Chen, Guangnan; Feng, Mengmeng; Dai, Huaming; Yuan, Bihe; Chen, Xianfeng

doi:10.1016/j.jhazmat.2018.08.087

Cited by 187 publications

(46 citation statements)

References 21 publications

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“…The mass decline of the silica blankets below 600 • C would mainly contribute to the degradation of side groups of PI, while the sharp decline over 600 • C must be due to the decomposition of the backbone of PI. Besides, the degradation of Si-CH 3 and Si-OH groups in the silica aerogels also occurred when the temperature was higher than 350 • C (He et al, 2019). However, due to the small fraction of the -CH 3 and -OH groups when compared to PI, the mass decline of the two groups was not obvious in the TGA curves.…”

Section: Resultsmentioning

confidence: 96%

Robust Silica–Polyimide Aerogel Blanket for Water-Proof and Flame-Retardant Self-Floating Artificial Island

Liu¹,

Wang²,

Liao³

et al. 2021

Front. Mater.

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A robust silica–polyimide (PI) aerogel blanket is designed and synthesized using the PI foam as the matrix and silica aerogel as the filler through an in situ method, where sol–gel transition of silica precursor occurs in pores of the PI foam, followed by the hydrophobization and ambient pressure drying. The density of the aerogel blanket ranges from 0.036 to 0.196 g/cm3, and the low density is directly controlled by tailoring the silica concentration. The specific surface area of the aerogel blanket reaches 728 m2/g. These features of the blanket result in a low thermal conductivity of 0.018 W/mK, which shows a remarkable reduction of 59% compared to that of the PI foam (0.044 W/mK). As a result, a remarkable decrease of 138°C is achieved using the silica blanket as the thermal insulator on a hot plate of approximately 250°C. In addition, the temperature degradation of the blanket is around 500°C, and up to 86% of mass remaining at 900°C is obtained. The blanket is resistant at extremely harsh conditions, e.g., 600°C for 30 min and 1,300°C for 1 min, and no open flame is observed, suggesting a significant flame-retardant of the blanket. Owing to the three-dimensional (3D) porous framework of the PI foam, the silica aerogel is encapsulated in the PI foam and the blanket exhibits strong mechanical property. The silica–PI aerogel can be reversibly compressed for 50 cycles without reduction of strain. The contact angle of the blanket is 153°, which shows a superior waterproof property. Combining with the low density, low thermal conductivity, flame-retardant, and strong mechanical strength, the aerogel blanket has the potential as an artificial island, which is safe (waterproof and flame-retardant), lightweight, comfortable, and easy to be moved.

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Section: Resultsmentioning

confidence: 96%

Robust Silica–Polyimide Aerogel Blanket for Water-Proof and Flame-Retardant Self-Floating Artificial Island

Liu¹,

Wang²,

Liao³

et al. 2021

Front. Mater.

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“…The value of bulk density was measured by using the mass of given volume and the skeleton density is 2.2 g/cm 3 29 …”

Section: Methodsmentioning

confidence: 99%

Efficient reinforcement of wet gel by embedded polymer as newly approach for silica aerogel

Bananifard

Ashjari

Niazi

et al. 2020

Polymers for Advanced Techs

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Silica aerogel as an ultra-porous material with high specific surface area is fabricated through drying a wet gel. Although ambient pressure drying is considered as simplest method, the obtained physical properties are not very desired. Here, we introduced a novel approach to improve the efficiency of ambient pressure drying technique by enhancing the strength and firmness of pores walls. The tetraethyl orthosilicate was used to produce the wet gel. The gel network was reinforced via embedding the polyvinyl alcohol cross-linkable polymer into porosities of wet gel, and drying at ambient condition, forming an interpenetrating network. The thermal treatment was applied to remove the polymeric phase from structure of reinforced network. A proper specific surface area, good density, and high porosity were achieved about 503 m 2 /g, 0.23 g/cm 3 , and 89%, respectively. Furthermore, the obtained interconnected structure along whit large numbers of open mesopores confirms the acceptable efficiency of introduced facilitated technique.

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“…Heat treatment is the conventional method reported for CTAB removing (He et al, 2019;Lei et al, 2017). For instance, Vidonish et al, Santos-Beltran et al, have reported that is effective in the removal of organic compounds like CTAB in compounds with silica (Vidonish et al, 2016;Santos-Beltran et al, 2018) however, some studies have shown that thermal treatment could change the particle structure and affect its final function (Lei et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Effect of thermal and argon plasma treatment in SiO2 spheres, assessing the effectiveness in the elimination of organic waste

Narro-Céspedes¹,

Reyna-Martinez²,

Ibarra-Alonso³

et al. 2020

Rev.Mex.Ing.Quim.

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Effect of heat treatment on hydrophobic silica aerogel

Cited by 187 publications

References 21 publications

Robust Silica–Polyimide Aerogel Blanket for Water-Proof and Flame-Retardant Self-Floating Artificial Island

Robust Silica–Polyimide Aerogel Blanket for Water-Proof and Flame-Retardant Self-Floating Artificial Island

Efficient reinforcement of wet gel by embedded polymer as newly approach for silica aerogel

Effect of thermal and argon plasma treatment in SiO2 spheres, assessing the effectiveness in the elimination of organic waste

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