Surface characterization of chitosan film modified by ion beam

Abstract

The surfaces of chitosan film were modified by He+, Ar+, Kr+, N2+ and O2+ beams and were characterized. An ion beam was irradiated at an energy level of 150 keV with fluences of 10^13, 10^14 and 10^15 ions/cm^2. The modified surfaces were characterized by Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurement. The FT-IR measurement demonstrated that the original structure was destroyed and a new functional group was produced. The Raman spectroscopy revealed that an amorphous carbon phase was induced by ion beam. The XPS results indicate that the atomic percentage of carbon increases with ion fluences for each ion species. The average surface roughness (Ra) increased with the ion fluence when compared with the non-irradiated chitosan film surface. With a fluence of 10^15 ions/cm^2 all substrates displayed wettability of 70 to 72°.