Glow-discharge (cold plasma) polymerization for coating the internal surface of a catheter

Glow discharge polymerisation (cold plasma) of hexamethyldisiloxane (HMDSO) monomer was performed for coating the internal surface of a catheter (1 mm internal diameter) with the aim of improving its biocompatibility. The catheter itself is used as a reactor in which an electrical discharge was generated at 13,56 MHz. The optical emission analysis of the plasma shows CH radicals and hydrogen (H and H-2) in the discharge. The films were characterised by electron microscopy and Fourier transform infrared spectroscopy (FTIR) under different monomer pressures (from 1,3 Pa to 13,3 Pa). The FTIR spectra of poly(hexamethyldisiloxane) (pHMDSO) revealed a more cross-linked or branched polymer with long linear chains at 1,3 Pa than at higher pressures (up to about 13 Pa). This original polymerisation set-up has shown remarkably significant deposition rates (up to 60 nm sec-1). (C) 1996 Elsevier Science Ltd