Positron Lifetime Annihilation Study of Porous Composites and Silicas Synthesized Using Polymer Templates

摘要

The porous structure of polymer-silica composites, based on three polymer templates, which differ in a porosity and hydrophobicity, was examined using positron annihilation lifetime spectroscopy. Additionally, the investigation of silicas obtained after removal of polymers during calcination of composite materials, was performed. In composites based on hydrophobic polymers, silica condensates only in larger free volumes, while SiO_2 deeply penetrates spaces between polymer chains, when the template is polar. Moreover, the structure of the silica gel, obtained after polymer removal, depends on chemical character of the template, rather than its porosity.