Synthesis of silica aerogels microspheres prepared by ink jet printing and dried at ambient pressure without surface hydrophobization

Silica aerogel microspheres were synthesized by sol gel process via ambient pressure drying using tetraethylorthosilicate as precursor, and ink jet printing to shape the microspheres. Aerogels were synthesized with and without the surface hydrophobization step and at different volumetric ratios of sol precursor and a continuous oil phase, which was used to stabilize the spheres ejected by printer. By the first time, SiO2 aerogel precursor was successfully ambient dried without modification step, keeping its integrity (cracks free) and with minimal size contraction, which was verified by comparison with the aerogel spheres obtained by the process of surface hydrophobization and drying. (C) 2015 Elsevier B.V. All rights reserved.