IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Tuesday Sessions
       Session BI-TuP

Paper BI-TuP2
Short-term Oxidation of Polymer Films Deposited from Pulsed Radiofrequency Allylamine Plasmas

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Surface Characterization and Non-Fouling Surfaces Poster Session
Presenter: J.D. Whittle, University of Texas at Arlington
Authors: J.D. Whittle, University of Texas at Arlington
G.R. Kinsel, University of Texas at Arlington
R.B. Timmons, University of Texas at Arlington
Correspondent: Click to Email
Plasma deposited films are seen as a promising route to the synthesis of novel functional coatings for a large number of potential applications. Allylamine deposited films in particular are of great interest in the biomaterials field as surfaces for protein adsorption. Studies of the long-term aging of these plasma polymers have shown that the oxygen content of the films changes over extended periods of time. Earlier work has shown that the oxygen content of allylamine films deposited from continuous wave plasmas increased from around 2% for a fresh sample, to around 10% after a year of aging in the laboratory, with the greatest change in composition being within the first 48h. In addition, some loss of nitrogen from the films has also been observed. In this study, we concentrate on the changes in chemistry over the first few days, and in particular the first 12 hours following deposition. The surface chemistry is investigated by X-ray photoelectron spectroscopy (XPS) and Matrix Assisted Laser Desorption/Ionization Mass spectrometry (MALDI-MS). Using XPS we investigate the stability of the plasma polymer surfaces in the UHV environment using different substrates for deposition to determine what the source of the oxidative species may be. A small amount of oxygen is always present in these plasma polymers, which may be due to the unavoidable exposure to the atmosphere between completing the deposition, and insertion of the sample into the spectrometer. Further, by analyzing samples exposed to the laboratory atmosphere for specific lengths of time, we show how the surface chemistry evolves in the first few hours following deposition. We also examine the effect of plasma power and pulsing duty cycle on the post-deposition properties of the films.