Synthesis of TiO 2 nanoparticles using amphiphilic POEM- b-PS- b-POEM triblock copolymer template film

Abstract

A novel ABA-type triblock copolymer, i.e. poly(oxyethylene methacrylate)- b-polystyrene- b-poly(oxyethylene methacrylate) (POEM- b-PS- b-POEM) was synthesized via atom transfer radical polymerization (ATRP). This amphiphilic triblock copolymer was used to template the growth of TiO 2 from a titanium isopropoxide through sol–gel process in the solid state film. The hydrophilic titania precursor was selectively incorporated into hydrophilic POEM domains and formed TiO 2 nanoparticle arrays, mostly due to microphase separation between the PS domains and the POEM/TiO 2 domains. High-density arrays of TiO 2 nanoparticles with 30–40 nm size after calcinations at 550 °C were confirmed by X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, wide angle X-ray scattering (WAXS) and transmission electron microscopy (TEM). The resultant TiO 2 nanoparticles showed high photocatalytic activity on the photodegradation of humic acid.