Freeze-align and heat-fuse: Microwires and networks from nanoparticle suspensions

Abstract

Staying in line: Aqueous colloids (particle diameter 10-500 nm) are directionally frozen and freeze-dried to produce aligned microwires, which can be fused together by heat treatment with complete retention of the morphology. The method is generic: by controlling surface charge, the approach can be applied to metals, metal oxides, and organic polymers. A single microwire formed by the assembly of polystyrene colloids is shown. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.