Pickering Inverse Miniemulsion Self-assembled Hybrid Nanomaterials To Form Nanospheres And Their Properties

The nanomaterials can be self-assembled by inverse Pickering miniemulsion.In the present research,the nanospheres with different structures were self-assembled by inverse Pickering miniemulsion,using modified zinc oxide(ZnO),cadmium oxide(CdO)and copper oxide(CuO)crystals as solid stabilizers.They were composed of organic-inorganic hybrids nanomaterials or inorganic-inorganic hybrid oxide nanocrystals.The main research contents are as follows:Firstly,the sol-gel method was used to synthesize ZnO nanocrystals;the hydrothermal method and calcination method were used to prepare CdO nanocrystals;and the precipitation method and calcination method were applied to synthesize CuO nanocrystals;and then the surface of the oxides nanocrystals was modified by 3-(methacryloxy)propyltrimethoxy-silane(MPS).The influence of crystallization temperature on the morphology and particle size of oxide nanocrystals were researched;and then the influence of the amount of MPS on three-phase contact angle were investigated.Through controlling the crystallization temperature,the ZnO,CdO and CuO nanocrystals were successfully prepared with the controllable morphology and particle size.The results show that the increase of the crystallization temperature resulted in the increase of the nanocrystals size of ZnO and CdO nanocrystals,and the disassemble of CuO nanocrystals from layer strips to scattered particles.With the increase of the amount of MPS,the three-phase contact angle of three kinds of nanocrystals increased.Secondly,the modified ZnO,CdO and CuO nanocrystals were used as solid stabilizers in inverse Pickering miniemulsion.The effects of the factors such as the type of nanocrystals,the dosage and the three-phase contact angle,the oil-water volume ratio and the Na Cl concentration on the stability and droplet size of inverse Pickering miniemulsion were investigated.The results show that the modified ZnO,CdO and CuO nanocrystals well-stabilized the inverse Pickering miniemulsion individually.The dosage and the three-phase contact angle of modified nanocrystals,oil-water volume ratio and Na Cl concentration had significant effects on the stability of inverse Pickering miniemulsion.Thirdly,the nanospheres with double-layer structure(ZnO@polyisopropylacrylamide(PNIPAM),ZnO@PNIPAM)were self-assembled by inverse Pickering miniemulsion,which the modified ZnO nanocrystals had attached on the interface-layer of PNIPAM.The self-assembly mechanism of modified ZnO nanocrystals at the oil/water interface was suggested.The successful self-assemble of ZnO@PNIPAM nanospheres were well-proved by comparing the energy spectrum of ZnO@PNIPAM nanospheres before extracting with that after extracting.The extracted ZnO@PNIPAM nanospheres exhibited strong ultraviolet absorption characteristics and luminescence intensity.Finally,by optimizing the dosage ratio,the three-phase contact angles of nanomaterials and setting their initial dispersion positions in inverse Pickering miniemulsion,the hybrid oxide nanocrystals of ZnO,CdO or CuO mixture were self-assemble into four kind structure of nanospheres,namely the nanospheres of core/shell,of double layer,of mixed single layer,and of mixed ZnO-CuO layer at CdO layer(ZnO-CuO@CdO).The results are that ZnO-CuO@CdO nanospheres showed the unique characteristics of optical absorption and charge transfer.In summary,the nanospheres self-assembled by the hybrid nanocrystals were successfully prepared by inverse Pickering miniemulsion.The nanospheres processed the different structures and the perfect morphologies,they provided the good photoelectric performance.