Abstract: The surface modification on the nano-ZnO particles was made by using coupling agent of KH550, and the thin film of PMMA/nano-ZnO was prepared by spin-coating method, and the ultraviolet shielding properties of thin films was studied in this article, the results show that the modified nano-ZnO have no sediment in water and toluene, and the solubility of particles improve obviously; a new absorption peak is found at 877 cm -1 in the FTIR spectrum of modified nano-ZnO, which confirm that the particle surfaces have been modified by the coupling agent; optical microscope and AFM show that the agglomeration of modified nano-ZnO decrease remarkably in the PMMA film, and dispersity of the particles improve; when the concentration of PMMA in toluene was 0.04 g/mL, and the weight content of nano-ZnO in PMMA was 10%, the film has a best ultraviolet shielding properties, and the transmission rate of ultraviolet is 0.66, compared with the film above, the ultraviolet shielding properties of the film with the same content of modified nano-ZnO improve distinctly, and the transmission rate of ultraviolet is 0.53.

Key words: polymethylmethacrylate, nano-zinc oxide, thin film, ultraviolet shielding