Preparation and Structural Characterization of Silica/OrganoclayNanocomposite Aerogels

In this work, the effect of adding organoclay on the microstructure of silica aerogels was investigated. Silica aerogels were prepared by hydrolysis of tetraethyl orthosilicate (TEOS) in methanol/water followed by gelation anddrying under supercritical condition. In order to prepare the nanocomposite aerogels, organoclay as nanofiller in three levels, i.e. 0, 3 and 5 wt. % based on silica content in dried gel, was added to sol before gelation. The XRD resultsconfirmed exfoliated morphology for nanocomposite aerogels. The scanning electron microscopy (SEM) was also used to characterize the microstructure of aerogels. They are comprised of a few nanometer SiO2 particles even in presenceof organoclay. The surface area and porosity of silica/organoclay nanocomposite aerogels were determined by N2 adsorption analysis. All nanocomposite aerogels were mesoporous with a specific surface area of 770 - 780 m2.g-1.

کلیدواژه ها:

Silica aerogel ، Nanocomposite ، Sol-gel ، Supercritical drying ، Organoclay