AVS 49th International Symposium
    Plasma Science Wednesday Sessions
       Session PS+BI-WeA

Paper PS+BI-WeA9
Acrylic Acid Films Deposition by RF PACVD: Relation between Monomer Fragmentation and Surface Properties

Wednesday, November 6, 2002, 4:40 pm, Room C-103

Session: Plasma Processing for Biocompatible Surfaces
Presenter: F. Rossi, European Commission, Joint Research Centre, Italy
Authors: P. Rossini, European Commission, Joint Research Centre, Italy
G. Ceccone, European Commission, Joint Research Centre, Italy
K. Jandt, University Jena, Italy
F. Rossi, European Commission, Joint Research Centre, Italy
Correspondent: Click to Email
The present study deals with the deposition of acrylic acid thin films by radio frequency plasma assisted chemical vapour deposition. The experiments have been carried out in a cylindrical capacitively coupled plasma reactor at different electrical powers (5-60 Watt), in order to optimise the precursors fragmentation and to tune selectivity and stability of the deposited polymers. In situ diagnostics (Mass Spectrometry and Optical Emission Spectroscopy) have been used in order to control the deposition processes and analyse the fragmentation steps. The films have been characterised with X-Ray Photoemission Spectroscopy (XPS) and Fourier Transformed Infrared Spectroscopy (FTIR). Surface energy of the coatings has been determined by contact angle measurement. The protein adsorption kinetics has been evaluated with the Quartz Crystal Microbalance (QCM-D) with HSA. The results demonstrate a strong link between monomer fragmentation in the plasma and functional groups retention in the films. By increasing the RF power, the COOH concentration in the films (XPS and FTIR) as well as hydrophylicity, hydrogen bondings and acid-base character decrease while the CO concentration in the plasma phase (MS and OES) increases. At the same time, the dispersive and the polar components of the surface free energy increase. These surface properties have a strong influence on the protein attachment kinetics, as determined by QCM measurements.