Glen C. Irvin

ZnO/PMMA Thin Film Nanocomposites for Optical Coatings

The optical properties of nano-scale zinc oxide/PMMA composites were investigated. Films were produced by spin coating and cast coating dispersions of nanoparticle/PMMA organic solutions. This allows for the preparation of nanocomposite films with controlled thickness containing up to 22 vol. % homogeneously dispersed nanofillers. It was found that the refractive index of the composite films scaled linearly with volume fraction of nanofillers. The films were transparent in the visible light range and strongly absorbing in the UV range. When the films were loaded with a high content of such semiconductor nanoparticles, the surface resistivity decreased enough for the coatings to be used for antistatic applications.

Enhanced Scratch Resistance of Nanocomposite Gelatin Films

Nanocomposites were made using deionized gelatin filled with well-dispersed nanoscale alumina particles. Scratch tests on the nanocomposite films showed substantially improved scratch resistance. Tensile tests revealed increases in both modulus and tensile strength of the nano-filled gelatin films accompanied by a decrease in strain-to-failure. The increase in modulus and strength reduced the degree of plastic deformation during scratch testing, but the onset of periodic cracking in the scratch track was unaffected. Optical transmittance measurements of the gelatin composite showed that the films retained transparency in the visible light range.