Preparation of Nanoporous Mondispersed Silica Nanoparticles Films Using Poly(styrene)- Block-Poly( 2-Vinyl Pyridine) as Template

Abstract

Nanoporous silica films were prepared through the templating of amphiphilic block copolymer, poly(styrene-2-vinyl pyridine) (PS-b-P2VP), and colloidal silica nanoparticles. The experimental and theoretical studies suggested that the intermolecular hydrogen bonding was existed between the colloidal silica nanoparticles and PS-b-P2VP. The miscible hybrid and the narrow thermal decomposition of the PS-b-P2VP led to nanopores in the prepared films from the results of TGA, AFM, and TEM. The effects of the loading ratio and P2VP chain length on the morphology and properties of the prepared nanoporous silica films were investigated. The TEM and AFM studies showed that the uniform pore morphology with pore size 10-15nm was prepared from a modest porogen loading level for the optimum intermolecular hydrogen bonding. The refractive index and dielectric constant of the prepared nanoporous films decreased with an increase in PS-b-P2VP loading. On the other hand, the porosity increased with an increasing PS-b-P2VP loading. This study demonstrated a methodology to control pore morphology and properties of the nanoporous silica films through the templating of PS-b-P2VP.