The influence of UV irradiation on surface composition of collagen/PVP blended films

The surface chemical composition and surface properties of collagen/poly(vinyl pyrrolidone) (PVP) blended films before and after UV irradiation (l = 254 nm) were investigated using X-ray Photoelectron Spectroscopy (XPS), FTIR–ATR spectroscopy and Atomic Force Microscopy (AFM). The XPS results showed that collagen is enriched on the surface of the collagen/PVP blend. The surface composition of the collagen film was changed more by UV irradiation than the surface composition of the collagen/PVP blend. FTIR–ATR spectra showed that the positions of the amide bands in collagen are more altered after UV irradiation than those for the collagen/ PVP blends. AFM images showed that the collagen surface is ordered contrary to PVP. The blend surface was similar to the pure collagen surface and confirms that there is more collagen present at the surface (higher concentration of collagen at the surface compared to PVP). UVirradiation caused only the small changes in the surface morphology of the collagen/PVP films. All of the results confirm that the surface of the collagen/PVP blend is more photoresistant than collagen