Preparation and Hydrophobic Properties of Polyborosilazane Aerogels <i>via</i> CO₂ Supercritical Drying

Abstract

The polyborosilazane aerogels were prepared by hydrosilylation reaction using polyborosilazane as raw material with divinylbenzeneas crosslinking agent, and then dried by CO2 supercritical drying. Infrared spectroscopy, scanning electron microscopy, specific surface area and aperture analyzer,contact angle measurement were used to characterize the formation, microstructure and hydrophobic property of polyborosilazane aerogels. The results show that the polyborosilazane aerogels are prepared by hydrosilylation reaction using polyborosilazane with divinylbenzene; the specific surface areas of the resultant aerogels with three-dimensional network structure are in the range of 307-458cm2/g, which is a mesoporous material with superhydrophobic property. The pore volume is in the range of 1.20-2.17cm3/g and pore size is in the range of 2.0-100nm, and when the volume fraction of the starting solvent is 85%, the hydrophobic performance of polyborosilazane aerogels is the best, the water contact angle is 151.5°.

Keywords

• polyborosilazane
• hydrosilylation reaction
• aerogel
• CO₂ supercritical drying
• hydrophobic property