Glow discharge plasma deposited hexafluoropropylene films: surface chemistry and interfacial materials properties

Fluoropolymer films prepared by radio frequency glow discharge (RF-glow dis charge) are of interest as biomaterials coatings. Previous studies focused on hexafluoroethane (C2F6, HFE) and tetrafluoroethylene (C2F4, TFE) as the monomer precursor have shown such surfaces to exhibit unique protein bindin g capabilities. In this study, slow, surface directed deposition of hexaflu oropropylene (C3F6, HFP) films is shown to confer surface functional group presentation that promotes high protein retention. The surface chemistry is controllable over a range of values, and C3F6 films prepared by RF-glow di scharge are smooth, homogeneous, and defect free. Surface patterns of the f luoropolymer can be created by direct or photolithographic techniques. Scan ning probe microscopic analysis indicates a surface modulus in the range of 1.2 < E-HFP < 5.5 GPa. These results are discussed in terms of the applica bility of C3F6 films for coating biomaterials. (C) 1999 Published by Elsevi er Science S.A. All rights reserved.