In situ crosslinking of silica aerogel with reactive carbon fiber for high mechanical property, thermal insulation and superhydrophobicity

Abstract

In this study, a novel silicon hydroxyl groups decorated long carbon chain grafted carbon fiber was synthesized, and a facile fabrication method was developed to produce reactive carbon fiber-silica aerogel composite with chemical crosslinking structure. Scanning electron microscopy images showed that silica aerogel matrix is wrapped on the surface of reactive carbon fibers. The reactive carbon fibers facilitated obstacle in shrinkage, and aerogel composites exhibited microporous behavior with average diameter of about 1.8 nm. Fourier-transform infrared and X-ray photoelectron spectroscopy confirmed the strong interfacial interaction between reactive carbon fibers and silica matrix. The modification mechanism of silicon hydroxyl groups decorated long carbon chain grafted carbon fiber, and the chemical crosslinking in aerogel composite were proposed. The reactive carbon fiber-silica aerogel composites synthesized in this work had been proved to have low density, excellent mechanical property, good tailoring performance, improved thermal stability, low thermal conductivity, high flame retardancy, high thermal insulation property, and superhydrophilicity. Hence, this work provided a theoretical basis for improving the performance and expanding the application of silica aerogel.