Nonlinear Optical Behavior of Transparent Nanohybrids of Nanocrystalline TiO2 in Poly(methyl methacrylate) Prepared by In Situ Sol-Gel Polymerization Technique
Nanohybrid thin films consisting of nanocrystalline TiO2 particles in poly(methyl methacrylate)(PMMA) were successfully synthesized by in-situ sol-gel and polymerization assisted by spin coating. Using titanium isoproproxide (Ti-iP), methyl methacrylate (MMA) and 3-(trimethoxysily)propyl methacrylate (MSMA) as the starting materials, nanohybrids containing up to 60% Ti-iP in PMMA were realized. The resulting nanohybrid thin films coated on quartz substrates are optically transparent and demonstrate nonlinear optical behaviour, where their nonlinear absorption increases with the loading of Ti-iP in PMMA, as confirmed by Z-scan measurements. Using pump-probe technique, these thin films are shown to exhibit an ultrafast relaxation time of ~1.5 picosecond.
M. Gupta and Christina Y.H. Lim
A.H. Yuwono et al., "Nonlinear Optical Behavior of Transparent Nanohybrids of Nanocrystalline TiO2 in Poly(methyl methacrylate) Prepared by In Situ Sol-Gel Polymerization Technique", Journal of Metastable and Nanocrystalline Materials, Vol. 23, pp. 367-370, 2005