Self-assembly of ultrathin composite TiO_2/polymer films

摘要

A wet layer-by-layer self-assembly of composite TiO_2/polymer films on Si and Al_2O_3/Al, substrates has been studied by AFM, STM, and ellipsometry techniques. The quality of the first adsorbed TiO_2 layer has been found to be the governing factor in multilayer film growth. The first layer consists of single particles and particle agglomerates 30-120 nm wide The surface coverage in the layer is determined by the chemical composition of the substrate surface and water pH in post-adsorption rinsing procedure. Well-packed TiO_2/polymer film completely covering the surface has been prepared in five adsorption cycle on Al_2O_3/Al substrate. The film remained crack-free after heat treatment at 300 °C. I-V curves measurement reveals high resistivity (R ～ 10~(10) O in the voltage range from -2 to +3 V) of TiO_2/polymer films prepared in ten adsorption cycles.