Chemical Structure and Properties of Plasma-Polymerized Maleic Anhydride Films

Plasma-assisted polymerization of maleic anhydride has been investigated under different experimental conditions. Significant variations in the film chemical structure and the film properties were obtained using pulsed plasma depositions operated at different duty cycles. The film chemical structures were obtained using X-ray photoelectron spectroscopy (XPS) and Fourier transform infra red spectroscopy (FT-IR). Surface derivatization reactions using decylamine and benzylamine were used to demonstrate their surface reactivity toward nucleophilic moieties and to change the surface free energy of the plasma polymer films, all of which are of particular interest for future applications in the attachment of biological molecules and cells. A method of substrate pretreatment was developed to ensure reliable binding between the substrate and the plasma polymer film in aqueous solution. Impedance spectroscopy was used to monitor polymer film changes in aqueous media. The hydrated films showed some resemblance to polyelectrolyte films and a clear correlation could be observed between the density of anhydride groups and the behavior of the films in solution.