Template-assisted encapsulation of fluorinated silanes in silica films for sustained hydrophobic-oleophobic functionality

This work explores the use of templated silica films as scaffolds for encapsulating surface-segregating functional organic moieties as a mesoscopically dispersed phase with the goal of imparting sustained functionality. Block copolymer surfactant templated hydrophobic-oleophobic fluorinated silica films were synthesized via sol-gel co-condensation and coated on glass substrates. Fluorosilane and surfactant template concentrations were varied, and coating surface properties measured before and after abrasion of the top surface. Surface physical and chemical properties were investigated using XPS and contact angle measurements. Nitrogen adsorption porosimetry and TEM were used to examine the effect of templating and fluorosilane encapsulation on the surrounding silica framework. The results show that surfactant template concentration may be used to tune the dispersion of the fluorosilane-rich phase within the silica film in order to allow exposed surfaces to maintain much of the original functionality of the pristine top surface. (C) 2011 Elsevier Inc. All rights reserved.