View cell investigation of silica aerogels during supercritical drying: Analysis of size variation and mass transfer mechanisms

摘要

Aerogels are a dass of materials with extraordinary properties resulting from their nanoporosity. That makes of them suitable materials for different interesting applications. On the other hand, silica aerogels are very brittle structures and use to crack during the drying step of their production. Several techniques have been used in order to dry the aerogels like the atmospheric or freeze drying but the supercritical drying in which the alcohol is solved in a supercritical fluid seems to be the way to overcome the collapse of the structure. But even employing supercritical methods, certain shrinkage of aerogels due to morphological variations is frequently observed after drying.