Journal ArticleDOI
Preparation of Monolithic Silica Aerogel of Low Thermal Conductivity by Ambient Pressure Drying
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TLDR
In this article, tetraethoxysilane (TEOS)-derived wet gel was made hydrophobic with multiple treatments of trimethylchlorosilane and dried under ambient pressure.Abstract:
Monolithic silica aerogels with thermal conductivity as low as 0.036 W·(m·K)−1 and porosity as high as 97% were successfully prepared by ambient pressure drying through a multiple modification approach. This approach may replace the more costly and dangerous operation of supercritical drying. The tetraethoxysilane (TEOS)-derived wet gel was made hydrophobic with multiple treatments of trimethylchlorosilane and dried under ambient pressure. The multiple treatments were found to be necessary to achieve sufficient modification of the wet gel for reduction in drying-induced surface tension force to maintain product integrity and high porosity. Comparisons in nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy for surface bonding and contact angle measurement for hydrophobicity between the no, single, and multiple surface modification (MSM) samples were conducted to reveal the difference in the extent of the resulting surface modification. In conclusion, the MSM procedure reduced the volume shrinkage, increased the monolithicity and porosity, and lowered the thermal conductivity of the resulting aerogels.read more
Citations
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Journal ArticleDOI
A Cost-Effective Supercapacitor Material of Ultrahigh Specific Capacitances: Spinel Nickel Cobaltite Aerogels from an Epoxide-Driven Sol–Gel Process
TL;DR: This work reported the first successful preparation of nickel cobaltite aerogels with the epoxide-driven sol–gel process, which showed an extremely high-specific capacitance of 1400 F g under a mass loading of 0.4 mg cm 2 at a sweep rate of 25mV s.
Journal ArticleDOI
Cobalt Oxide Aerogels of Ideal Supercapacitive Properties Prepared with an Epoxide Synthetic Route
TL;DR: In this paper, an epoxide addition procedure was used to synthesize high performance supercapacitors of the asymmetric type using cobalt oxide aerogels as the precursor.
Journal ArticleDOI
Ultralight, scalable, and high-temperature–resilient ceramic nanofiber sponges
Haolun Wang,Haolun Wang,Xuan Zhang,Ning Wang,Yan Li,Xue Feng,Ya Huang,Chunsong Zhao,Zhenglian Liu,Minghao Fang,Gang Ou,Huajian Gao,Xiaoyan Li,Hui Wu +13 more
TL;DR: The manufacturing of large-scale, lightweight, high-temperature resilient, three-dimensional sponges based on a variety of oxide ceramic nanofibers through an efficient solution blow-spinning process is reported, and it is shown that ceramic nan ofibers can serve multiple functions, such as elasticity-dependent electrical resistance, photocatalytic activity, and thermal insulation.
Journal ArticleDOI
Hollow-Structured Materials for Thermal Insulation.
Feng Hu,Siyu Wu,Yugang Sun +2 more
TL;DR: A timely overview of the recent progress in developing HSMs for thermal insulation is presented, with the focus on summarizing the strategies for creating gaseous voids in solid materials and thus synthesizing various HSMs.
Journal ArticleDOI
Aerogels in Aerospace: An Overview
TL;DR: Aerogels are highly porous structures prepared via a sol-gel process and supercritical drying technology as mentioned in this paper, and they exhibit the most remarkable physical properties, possessing lower density, thermal conductivity, refractive index, and dielectric constant than any solids.
References
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Journal ArticleDOI
Chemistry of Aerogels and Their Applications
Alain Pierre,Gerard Pajonk +1 more
TL;DR: Aerogels form a new class of solids showing sophisticated potentialities for a range of applications, and can develop very attractive physical and chemical properties not achievable by other means of low temperature soft chemical synthesis.
Journal ArticleDOI
Coherent Expanded Aerogels and Jellies
S. S. Kistler,S. S. Kistler +1 more
TL;DR: The continuity of the liquid permeating jellies is demonstrated by diffusion, syneresis, and ultrafiltration, and the fact that the liquid may be replaced by other liquids of very diverse character indicates clearly that the gel structure may be independent of the fluid in which it is bathed as mentioned in this paper.
Journal ArticleDOI
Aerogels-Airy Materials: Chemistry, Structure, and Properties.
Nicola Hüsing,Ulrich S. Schubert +1 more
TL;DR: The design of such a filigrane network requires the very careful control of chemical parameters and the reward is an assortment of different property profiles owing to the richness of possible variations.
Journal ArticleDOI
Preparation of silica aerogel using ionic liquids as solvents
TL;DR: Ionic liquids have been used as effective solvents to synthesize aerogels; a long aging time can be used to produce stable aerogel structures without the need for supercritical drying processes as mentioned in this paper.
Journal ArticleDOI
Hydrophobic silica aerogels
H. Yokogawa,M. Yokoyama +1 more
TL;DR: The structure of trimethylsilyl modified silica aerogel (TMSA) was the silica matrix produced by hydrolysis and condensation of only tetramethoxysilane (TMOS).
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