Dattatreya M. Kadam, Mahendra Thunga, Gowrishanker Srinivasan, Micheal R. Kessler, David Grewell, Buddhi Lamsal, and Chenxu Yu
Iowa State University
Biodegradable corn zein protein (CZP) and whey protein isolate (WPI) films with TiO2@@SiO2 nanoparticles were prepared by solution casting technique. CZP and WPI solution with 1.5% of TiO2@@SiO2 was subjected different levels sonication (0, 10, 50 and 100%) to improve the mechanical properties and uniform distribution of nano particles in the films prior to casting. Mechanical and microstructural properties of nano functionalized films were determined by tensile testing and TEM, respectively. The results presented in this study show the feasibility of using bio-nanocomposite technology to improve the properties of CZP and WPI biopolymer films. The influence of blending TiO2@@SiO2 and sonication was systematically investigated. Films with nanoparticles showed better mechanical properties than films without nanoparticles but almost 50% reduction in elongation (tensile strain, %) was observed. Films without nanoparticle had lower tensile strength and higher percentage of elongation. Level of sonication and thickness of films has significant effect on tensile properties of CZP and WPI films with or without nanoparticles. TEM shows the distribution of TiO2@@SiO2 in the films. CZP sheet is also prepared using extrusion. First, pellets were made by dry extrusion and then subjected to extrusion through slit die to produce sheet/film whereas, CZP dissolved in ethanol and precipitate extrusion failed to yield any results.