Modification of surface properties of bell metal by radiofrequency plasma polymerization

Radiofrequency (RF) plasma polymerization is a convenient thin film deposition process as it facilitates the synthesisof polymer films with stable physico-chemical properties suitable for various applications in microelectronic, optical,and biomedical fields. The unique properties of these plasma polymerized films as compared to the conventionalones are strongly related to the proper adjustment of the external plasma discharge parameters and selection ofsuitable monomer. It is also important to study the fundamental chemistry of RF plasma polymerization process, sothat one can successfully correlate the internal features of the discharge with the film properties and explore theirpossible technological applications. The possibility of using styrene-based plasma polymer (SPP) films on bell metalas protective coatings is explored in this work. Depositions of the films are carried out in RF Ar/styrene discharge atworking pressure of 1.2 × 10(−1) mbar and at the RF power range of 20 to 110 W. Optical emission spectroscopy(OES) is used to study the active species generated during plasma polymerization, while Fourier transform infrared(FT-IR) and X-ray photoelectron spectroscopy (XPS) are used to analyze the internal chemical structures of the films.The protective performances of the SPP films are attempted to correlate with the results obtained from OES, FT-IR,and XPS analyses.

Keywords:

Radiofrequency glow discharge , Styrene-based plasma polymer films , Optical emission spectroscopy , Water repellency , Protective coating