Synthesis And Properties Of ZnO @ Polymer Hybrid Composites

In this paper, ZnO@polymer hybrid nanocomposites have been synthesized via two different methods. First, we synthesizd KH-570 surface modified ZnO QDs/PMMA, water-soluble ZnO@poly (AA-co-PEG) by solution polymerization. Then, we prepared different ZnO/PMMA by emulsion polymerization. The structures and optical properties of as-prepared samples were characterized via FT-IR,TG-DTA,SEM,Uv-Vis,PL,TEM and HRTEM,respectively. The details and results are summarized as followed:ZnO QDs/PMMA and KH-570 modified ZnO QDs/PMMA were successfully synthesized via in-situ polymerization, and their reaction mechanism and properties were studied. It was found that the the PL intensity was best when the molar ration of Zn and KH-570 was 3:2 and the modification process didn't alter the crystal structure of ZnO itself. The KH-570 molecules are working as a bridge connecting the ZnO QDs and the PMMA chains through both hydrolyzatioan and polymerization resulting in the good dispersion of ZnO QDs in the PMMA polymers. The photoluminescent properties of KH-570 modified ZnO QDs/PMMA polymer are found to be remarkably similar to the initial pure ZnO QDs and the PL intensity increased slightly; On the contrary, the main emission wavelength of the ZnO QDs/PMMA without KH-570 moved from 490nm to 510nm with a strong UV emission and the PL intensity decreased significantly. KH-570 stabilizer could play an important role in dispersing. So it could be prepared as optically transparent ZnO/PMMA films with strong UV absorption capacity, which may have benifits for the application in Optoelectronics.The ZnO@polymer core-shell nanoparticles with yellow or green emission were fabricated by initiating polymerization on ZnO nanocrystal surface using different zinc salts as precursor. It could effectively protect the ZnO to stable in aqueous solutions. First, we used PEG600 as surfactant, Zn (AA) 2 as zinc salts to prepare the stable aqueous core-shell nanaoparticles with tunable luminescence. Then, we chose Zn (Ac) 2 as zinc salts and NaAA as modifier to synthesis nanaocomposites with tunable luminescence similarly. Compared with tranditional ZnO QDs, the stability of the present ZnO@polymer in aqueous solutions greatly facilitates the application in biomedical labeling.The ZnO/PMMA composite particles were synthesized by emulsion polymerization. Here, we used two different ZnO as inorganic precursors, namely ZnO nanoparticles and ZnO QDs. It could be found that the as prepared ZnO/PMMA hybrids showed high UV-shielding efficiency and spherical morphology via modulating the components. If we embedded ZnO QDs into PMMA matrix, the green emission would move to the orange emission. And the products showed higher thermal stability than PMMA.