Depth Profile Assignments of nm and μm Orders by Quantum Chemical Calculations for Chitosan Films Modified by Kr + Beam Bombardment

Valence X-ray photoelectron and Raman spectra of a chitosan film modified by Kr+ion beam bombardment were analyzed from quantum chemical calculations. Experimental Raman spectra of the carbonized film with Kr+ion bombardment were found to be due to four component contributions of chitosan (Chito), diamond-like carbon (DLC), graphite (GP), and amorphous carbon (AC). By considering the four components contribution, we performed depth profile assignments in nm and μm ranges of the chitosan film in valence X-ray photoelectron spectroscopy and Raman shift experiments from calculations of the statistical average of orbital potential (SAOP) method of Amsterdam density functional (ADF) program, and B3LYP/6-31G(d, p) level in GAUSSIAN 09 software, respectively, using the model molecules. Carbonizations of the film by Kr+irradiation were obtained as Chito: DLC: AC: GP = 2:1:0.5:0.375 in the μm range from Raman shift analysis, while they were determined as Chito: DLC: AC: GP = 2:1:1:2 in the nm range from valence X-ray photoelectron spectral analysis.