Authors: F. Villafiorita Monteleone
Affilation: Center for Biomolecular Nanotechnologies @ UNILE, IIT, Italy
Pages: 616 - 619
Keywords: wettability control, TiO2/PS nanocomposites, layer-by-layer deposition, thin films
We propose an original method to modify and control the surface wettability properties of a specific material, by creating nanocomposite films on substrates with different surface properties, where the number of the deposited layers defines the final hydrophilicity of the coating. In particular, we prepared samples with one, two, or more successive layers of photopolymerized nanocomposite films containing TiO2 NRs as nanofillers and polystyrene as polymeric matrix, while the substrates used were glass slides and silicon wafers. The chosen substrates exhibit different chemical affinity with the NRs affecting their distribution in the matrix, and thus, the surface properties of the resulting material. In this scenario, the hydrophilic glass substrates attract the hydrophilic nanofillers, leading to a decreased number of NRs exposed onto the surface, and thus, to a quite hydrophobic surface. On the other hand, the more hydrophobic silicon surfaces show better affinity with the monomer, leading to samples with exposed NRs onto their surfaces, and thus with a higher degree of hydrophilicity.Adding one more layer of the same nanocomposite, the produced films show opposite characteristics. With each added layer the wetting characteristics of the samples swop.