Self-cleaning performance of polycarbonate surfaces coated with titania nanoparticles

The effect of NaOH-etching and UVC-irradiation on the mechanical stability of TiO2 nanoparticles on polycarbonate (PC) slides was investigated. TiO2 nanoparticles were found to adhere more strongly on UVC-treated PC than NaOH-etched PC, caused by the increase in the hydroxyl and carboxyl groups on the UVC-treated PC. Although a mechanically strong TiO2 film was developed on UVC-treated PC, the sheet-like wetting effect and antifogging behaviour were only observed with the film coated on NaOH-etched PC. It was also detected that the film coated onto NaOH-etched PC exhibited a more superior performance in degrading methylene blue than that in the UVC-treated PC system. Evidences from the FTIR and AFM analyses indicated that the performance of TiO2 films was strongly depended on the leaching rate of PEG.