Synthesis of TiO2 nanoparticles using amphiphilic POEM-b-PS-b-POEM triblock copolymer template film

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 TiO2 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 TiO2 nanoparticle arrays, mostly due to microphase separation between the PS domains and the POEM/TiO2 domains. High-density arrays of TiO2 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 TiO2 nanoparticles showed high photocatalytic activity on the photodegradation of humic acid.