In-situ synthesis and structural characterization of cellulose-silica aerogels by one-step impregnation

Cellulose-silica aerogels (CSAs) are organic-inorganic hybrid composites possessing both the porous characteristics and high mechanical properties. In this paper, two kinds of CSAs were in-situ synthesized by facile one-step impregnating cellulose layers directly into silica hydrosols and alcosols, respectively. The porous microstructures and the bonding linkage were investigated by means of Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption-desorption porosimetry. The results show that the silica particles successfully in-situ crosslink on/into the cellulose matrix and maintain the porous characteristics. The regeneration of the CAs directly in the alcosols is more beneficial to realize the crosslinking between silica particles and cellulose fibrils. The silica modification tends to increase the mechanical properties over those of the CAs due to the additional effects of silica particles impregnating into cellulose matrix.