IMPROVEMENT OF OPTICAL PROPERTIES OF ZnO-SILICONE NANOCOMPOSITES BY CHEMICAL GRAFTING
化学接枝改进ZnO-有机硅纳米复合材料的光学性能

N-(3-Trimethoxysilylpropyl)-4-azido-2,3,5,6-tetrafluorobenzamide (PFPA-silane) was used to modify zinc oxide (ZnO) nanoparticles.Then,the modified ZnO particles were grafted on silicone chains by PFPA-silane.There are two different reactive groups in PFPA-silane molecules,one reacts with hydroxyl on the surface of ZnO and the other one reacts with silicone chains by grafting reaction.Group variation during reaction was characterized by infrared spectroscopy (IR),and improvement of transparency of the composite after grafting reaction was recorded with ultraviolet-visible spectroscopy (UV-Vis).Change of refractive index was recorded with an Abbe refractometer.The influence of grafting reaction on transparency of the composite is analyzed with relationship between refractive index and light transmittance of composites.It can be concluded that refractive index of the nanocomposite is changed and the refractive index mismatch between ZnO nanoparticles and silicone matrix is reduced through grafting reaction,which benefits to decrease light scattering of ZnO nanoparticles and increase transparency of the composite.The maximal increase amount of light transmittance is 50% in this experiment.The result shows that the match between inorganic fillers and polymer matrix in refractive index can be adjusted by grafting reaction of coupling agent to polymer.The chemical grafting process is useful in preparation of high transparency inorganics-polymer nanocomposites.