Toward Mechanically-Robust Omniphobic Composite Coatings using Fluoroalkyl-Modified Silica (Preprint)
Abstract
The wide applicability of non-wetting materials has generated a surge in commerical, military, and academic materials research. Previous studies have elucidated three parameters useful in the development of non-wetting surfaces: chemical functionality (high fluorine content), multiple scales of surface roughness (nano and micro), and surface geometry (re-entrant curvature). These parameters have been used in the development of materials that are superhydrophobic and superoleophobic. Although many of these surfaces exhibit the desired omniphobic character, a simple method to produce mechanically robust non-wetting coatings on various substrates has not been reported. Various nanoparticles, such as nanosilica, have been shown to provide the required surface roughness for non-wetting character in polymer systems. In the present work, a fluoroalkyl-modified nanosilica is developed and investigated to help achieve both the surface roughness and low surface energy demands of an omniphobic polymer coating. The fluoroalkyl-modification has the added benefit of increasing dispersion and compatibility in a crosslinkable fluoropolymer matrix, which is thought to be needed to produce a mechanically-robust coating. Substitution of the silanol groups on the surface of silica has been well documented using vanous types of coupling agents, including chlorosilanes. The present work reports the modification of a previously reported two-step, amine promoted method for modifying the surface of silica.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 24, 2009
- Accession Number
- ADA506239
Entities
People
- Joseph M Mabry
- Raymond Campos
- Timothy S. Haddad