Thin Film Plasma Deposition of Allylamine; Effects of Solvent Treatment

Abstract

AbstractAmine-functionalized thin films were prepared by plasma induced deposition of allylamine. Radio frequency (rf) plasma polymerization was carried out under both continuous wave (CW) and pulsed plasma conditions to control the film chemistry, all other process variables being held constant. Using plasma polymerized films for subsequent grafting reactions or for direct biomedical applications usually involves exposure of the films to a solvent environment. It was the major focus of this work to investigate both the chemical and physical effects of solvents on plasma polymerized allylamine films. Film properties were determined using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Waveguide Mode Spectroscopy (WaMS) and Surface Plasmon Spectroscopy (SPS). WaMS provided an ideal opportunity to study the complex swelling and drying behaviour of these films by allowing a simultaneous study of the changes in film thickness and refractive index. Although the amine groups of the monomer were increasingly retained in the films as the RF duty cycle was lowered, a larger amount of oxygen was also found to be incorporated upon exposure to air. Extraction in ethanol led to a decrease in film thickness, especially for the films produced at low duty cycles, but appeared to have little effect on the film composition, as measured by XPS and FTIR.