(107c) Hybrid Colloid-Nanowire Structure and Assembly

A novel type of composite particles, microsphere-nanowire hybrid colloids, has been fabricated using self-assembly coupled particle formation process. Metallic nanowires are synthesized using electrodeposition in nanoporous templates, and the size of the nanowires ranges from 30-200 nm in diameter and micron-meters in length. Either polystyrene or silica particles are used as colloidal seeds. Polystyrene particles are synthesized by emulsion polymerization, while silica particles by sol-gel process. During colloidal formation, nanowires are added into the emulsions to initiate self-assembly to obtain colloid-nanowire structures. Results have been compared for using ionic vs. nonionic surfactants. Surface coverage of nanowires on colloids and the morphology of hybrid structures can be controlled by changing the relative concentrations between the colloids and nanowires, surfactant type, nanowire addition time, and the length of the nanowires. The network of the assembled structure can be obtained by sintering the hybrid colloids at high temperature or by the utilization of an external field (magnetic or electric).