2D nanodot and nanowires arrays of titania and silica with tunable morphologies via self-assembled block copolymers and sol-gel chemistry

Abstract

Hybrid thin films composed of poly(styrene-b-ethylene oxide)(PS-b-PEO) and TiO2 (or SiO2) with controlled morphology were fabricated using cooperative sol-gel chemistry and block copolymer(BCP) self-assembly. The inorganic precursors were selectively incorporated into PEO, and the volume fraction of PEO domain is increased with increasing sol-gel precursor/BCP ratio. The generated films exhibit various surface morphologies ranging from 0D nanodot to 1D nanowire arrays. If the composition of hybrid sol-gel/BCP is symmetric, the resulting film has nanowire morphology, whereas nanodot pattern was obtained from asymmetric composition. Given the same sol-gel precursor /BCP ratio, more uniform arrays of inorganic nanodots were induced when BCP template with asymmetric composition was employed.