Surface energy of the plasma treated Si incorporated diamond-like carbon films

Abstract

Surface energy and surface chemical bonds of the plasma treated Si incorporated diamond-like carbon films (Si-DLC) were investigated. The Si-DLC films were prepared by r.f plasma assisted chemical vapor deposition using benzene and diluted silane (SiH4/H-2=10:90) as the precursor gases. The Si-DLC films were subjected to plasma treatment using various gases like N-2, O-2, H-2 and CF4. The plasma treated Si-DLC films showed a wide range of water contact angles from 13.4 degrees to 92.1 degrees. The surface energies of the plasma treated Si-DLC films revealed a high polar component for O-2 plasma treated Si-DLC films and a low polar component for CF4 plasma treated Si-DLC films. The CF4 plasma treated Si-DLC films indicated the minimum surface energy. X-ray photoelectron spectroscopy (XPS) revealed that the polarizability of the bonds present on the surface explains the hydrophilicity and hydrophobicity of the plasma treated Si-DLC films. We also suggest that the 0, plasma treated surface can provide an excellent hemocompatible surface from the estimated interfacial energy between the plasma treated Si-DLC surface and human blood. (c) 2007 Elsevier B.V All rights reserved.