Preparation of SiO2/TiO2 Janus particles by electrostatic assembly, hydrolysis and calcination

This paper describes a novel chemical method for preparing SiO2/TiO2 Janus particles. First, polystyrene (PSt)/SiO2 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 SiO2 are investigated with respect to the surface charge density of the particles. SiO2/TiO2 Janus particles are then obtained by hydrolysis of butyl titanate on the surface of PSt/SiO2 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 SiO2 particles and the compositions and morphologies of PSt/SiO2, SiO2/TiO2 and PSt/SiO2/TiO2. The diameters of the PSt, SiO2, PSt/SiO2 and SiO2/TiO2 particles are 2.0 μm, 303 nm, 2.7 μm and 330 nm, respectively.

.Figure optionsDownload as PowerPoint slideHighlights
► A novel method for preparing Janus particles was proposed.
► PSt/SiO2 particles with raspberry-like structure were obtained via electrostatic assembly.
► SiO2/TiO2 Janus particles were prepared.