Fabrication and characterization of TiO2/whey protein isolate nanocomposite film

Composite films of whey protein isolate and TiO2 are formed through three simultaneous processes, i.e., the self-assembly of proteineprotein, TiO2-TiO2, and the association of protein-TiO2. All the processes could be controlled by adjusting TiO2 concentration in the blended system. The self-assembly of proteineprotein molecules constituted the main network of the composite film. A low TiO2 concentration (<0.25%) dispersed the TiO2 nanoparticles in the protein matrix, reinforced the association of protein-TiO2, reduced the ability of UVC absorption, and promoted the fluorescence and tensile strength of the composite films. In contrast, a high TiO2 concentration (>0.25%) enhanced the self-assembly of TiO2-TiO2 nanoparticles, brought fluorescent quenching, and produced a decline of the tensile strength and water vapor permeability. The transmittance of the visible, UVA, and UVB lights showed a first order exponential decay relative to the TiO2 concentration. (C) 2010 Elsevier Ltd. All rights reserved.