Cellulose Silica Hybrid Nanofiber Aerogels: From Sol-Gel Electrospun Nanofibers to Multifunctional Aerogels

Aerogels are considered ideal candidates for various applications, because of their low bulk density, highly porous nature, and functional performance. However, the time intensive nature of the complex fabrication process limits their potential application in various fields. Recently, incorporation of a fibrous network has resulted in production of aerogels with improved properties and functionalities. A facile approach is presented to fabricate hybrid sol-gel electrospun silica-cellulose diacetate (CDA)-based nanofibers to generate thermally and mechanically stable nanofiber aerogels. Thermal treatment results in gluing the silica-CDA network strongly together thereby enhancing aerogel mechanical stability and hydrophobicity without compromising their highly porous nature (>98%) and low bulk density (approximate to 10 mg cm(-3)). X-ray photoelectron spectroscopy and in situ Fourier-transform infrared studies demonstrate the development of strong bonds between silica and the CDA network, which result in the fabrication of cross-linked structure responsible for their mechanical and thermal robustness and enhanced affinity for oils. Superhydrophobic nature and high oleophilicity of the hybrid aerogels enable them to be ideal candidates for oil spill cleaning, while their flame retardancy and low thermal conductivity can be explored in various applications requiring stability at high temperatures.