Development of superhydrophobic hybrid silica-cellulose aerogel as promising thermal insulation and sound absorption

A cost-effective and facile synthesis method is developed for hybrid aerogels using recycled cellulose fiber concentration of 1-4 wt.% and methoxytrimethylsilane (MTMS). The developed hybrid aerogel was modified with surface hydroxyl groups to achieve superhydrophobic behavior with a contact angle as high as 163.4 degrees. This excellent three-dimensional reticular structure with various cellulose concentrations provides a thermal conductivity of 0.039-0.041 W m(-1) K-1. However, the thermal degradation of the hybrid aerogels exhibits a superior improvement with minimum weight loss. A comparatively good sound absorption coefficient of 0.392-0.504 was achieved with the inclusion of cellulose fiber concentration from 1 to 4 wt.% in comparison with silica aerogels (0.303-0.512). The experimental results also show an increase in compressive Young's modulus of hybrid aerogels up to 96%, with an increase in cellulose concentration. This work delivers a facile approach to developing hybrid aerogels with an industrial application to replace polymer-based insulations.