Fluoropolymer coating of medical grade poly(vinyl chloride) by plasma-enhanced chemical vapor deposition techniques
Medical grade poly(vinyl chloride) was modified by RF plasma-deposition of teflon-like coatings to create a platform for the physisorption of PEO-containing copolymers, Pluronics (R). Thin teflon-like coatings were deposited in an RF-plasma reactor by plasma-enhanced chemical vapor deposition (PE-CVD) methods, using hexafluoroethane (C2F6) as a precursor and H-2 as a carrier gas. A systematic study of the deposition parameters, C2F6 percentage in the C2F6-H-2 gas feed, power input and pressure was completed using Xray Photoelectron Spectroscopy and water contact angle measurements to characterize the various coatings. The surface analysis results were further correlated to the existing ionactivated growth model. XPS results indicated that the coatings which had the maximum fluorine incorporation, as determined by the F/C ratio, or CFx, functional groups, had the highest surface hydrophobicity. The parameters that were determined to yield the maximum contact angle (104 degrees) in the continuous power, RF regime were a high C2F6 percentage (80%) in the C2F6-H-2 gas feed and the mid-range power input and pressure values tested (30 W and 0.4 mbar).