Study On Preparation And Photoelectric Properties Of Composite Nanoparticles

In this paper,SiO₂ NPs were synthesized from TEOS by Sol-Gel method and was modified with surface C=C groups by using KH570.Through the dispersion polymerization,plystyrene was coated to SiO₂ NPs to form the core-shell structure.The effects of reaction conditions on the preparation process were discussed.The results showed that the core-shell composite nanoparticles with controllable particle size,uniform size distribution,and stable ratio of core and shell can be obtained.Fe₃O₄ NPs were synthesized by hydrothermal method using FeCl₃·6H₂O as raw material,and Fe₃O₄ NPs linked together with the SiO₂ layer by Sol-gel method to produce the core layer Fe₃O₄/SiO₂ NPs.The-OH groups on Fe₃O₄/SiO₂ NPs surface were modified with KH570,and C=C groups were bonded to the outer surface of Fe₃O₄/SiO₂ NPs.Through the dispersion polymerization of styrene on Fe₃O₄/SiO₂NPs,the core-layer-shell composite nanoparticles Fe₃O₄/SiO₂/PS NPs were obtained.The effects of reaction conditions on the morphology and particle size of Fe₃O₄ NPs and Fe₃O₄/SiO₂ NPs were discussed.The core-layer-shell composite nanoparticles with controllable particle size,uniform size distribution and stable three layer ratio can be successfully prepared in certain range of reaction conditions.Photonic crystals were prepared by using core-shell SiO₂/PS NPs and core-layer-shell Fe₃O₄/SiO₂/PS NPs.The structure of photonic crystal was characterized by SEM.The position of photonic band gap was characterized by UV-Vis.The experimental values of the band gap of the photonic crystal were compared with the theoretical values by the self-compiled plane wave expansion method.The effect of pressure on the band gap of photonic crystal was discussed.The results show that the experimental values and the theoretical values are basically mached with each other.The designed SiO₂/PS NPs and Fe₃O₄/SiO₂/PS NPs with hard core and soft shell presented the property of reversible pressure deformation,which afforded mechanical response property to the photonic crystal.Electrophoresis particles were synthesized via atom transfer radical polymerization?ATRP?in methanol and quaternization in acetonitrile.The two kinds of electrophoretic particles have good dispersity,and the surface charge densities were far greater than the cationic polymer-uncoated nanoparticles.Considering the Zeta potential,response time and structure of electrophoretic particles,TiO₂/SiO₂-CH NPs with the molar ratio of TiO₂/TEOS/DEGDMA/DMAEMA=1/0.2/0.015/0.6and 1/0.4/0.015/0.6,and Fe₂O₃/SiO₂-CH NPs with the ratio of Fe₂O₃/TEOS/HMA/PMDETA=1/0.2/0.01/0.06 and 1/0.5/0.01/0.06 were more suitable electrophoretic particles for the preparation of electronic inks.