This paper describes a novel chemical method for preparing SiO_2/TiO_2 Janus particles.First,polystyrene(PSt)/SiO_2 particles with a raspberry-like structure are prepared by electrostatic assembly.The influences of the reaction time of sulfonation and the treatment times of polyelectrolyte solutions(PDADMAC,PSS)on PSt and SiO_2 are investigated with respect to the surface charge density of the particles.SiO_2/TiO_2 Janus particles are then obtained by hydrolysis of butyl titanate on the surface of PSt/SiO_2 particles followed by a calcination process.Particle size analyzer,Zeta potential instrument,FTIR,TEM and SEM are used to characterize the particle size,the amount of charge on the surface of PSt and SiO_2 particles and the compositions and morphologies of PSt/SiO_2,SiO_2/TiO_2 and PSt/SiO_2/TiO_2.The diameters of the PSt,SiO_2,PSt/SiO_2 and SiO_2/TiO_2 particles are 2.0 μm,303 nm,2.7 μm and 330nm,respectively.
Baoliang ZhangQiuyu ZhangHepeng ZhangXinlong FanDezhong YinXiangjie LiWei Li
This article presents a facile approach to preparation of polystyrene/silver(PS/Ag) asymmetric hybrid particles.In this method,polystyrene/polyglycidyl methacrylate(PS/PGMA)Janus particles were synthesized via internal phase separation triggered by evaporation of dichloromethane(DCM) from PS/PGMA/DCMin water emulsion droplets.Then,the Janus particles were aminated and sequentially carboxylated to obtain PS/PCMA-NHO_2 and PS/PCMA-COOH particles.Ag*self-assembled on the surface of PGMA hemisphere of the functionalized PS/PCMA particles by coordinating with amine/carboxyl.PS/Ag asymmetric hybrid particles with 7.29 wt%of Ag were obtained by reduction of Ag^+.Scanning electron microscopy,energy-dispersive X-ray spectroscopy and transmission electron microscopy results confirmed that Ag was asymmetrically distributed on the surface of polymer particles.
Xinlong FanQiuyu ZhangHepeng ZhangBaoliang ZhangChunmei LiXiangjie LiXingfeng Lei
