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- [2021] [황해진] Thermal Gelation for Synthesis of Surface-Modified Silica Aerogel Powders
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- 2022.11.17
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Thermal Gelation for Synthesis of Surface-Modified Silica Aerogel Powders
Abstract
A spherical silica aerogel powder with hydrophobic surfaces displaying a water contact angle of 147° was synthesized from a water glass-in-hexane emulsion through ambient pressure drying. Water glass droplets containing acetic acid and ethyl alcohol were stabilized in n-hexane with a surfactant. Gelation was performed by heating the droplets, followed by solvent exchange and surface modification using a hexamethyldisilazane (HMDS)/n-hexane solution. The pH of the silicic acid solution was crucial in obtaining a highly porous silica aerogel powder with a spherical morphology. The thermal conductivity, tapped density, pore volume, and BET surface area of the silica aerogel powder were 22.4 mW·m−1K−1, 0.07 g·cm−3, 4.64 cm3·g−1, and 989 m2·g−1, respectively. Fourier transform infrared (FT–IR) spectroscopy analysis showed that the silica granule surface was modified by Si-CH3 groups, producing a hydrophobic aerogel.논문정보
Gels 2021, 7, 242.
Received: 31 October 2021 / Revised: 25 November 2021 / Accepted: 25 November 2021 / Published: 29 November 2021
Authors: Kyoung-Jin Lee, Jae Min Lee, Ki Sun Nam and Haejin Hwang