(452d) Formation of Carboxylic Acid Nanorods On Oleylamide-Capped Au Nanoparticles

            This paper describes nanorod formation induced by nanoparticle seeds. Carboxylic acids self-assemble on graphite into an epitaxial pattern. However, this persistent pattern is changed into nanorods by nanoparticles. Two control parameters have been identified including nucleus/substrate contact angle and seed to critical nucleus size ratio. Effective carboxylic chain length and nanoparticle size range are identified, which can be related to the seed size effect. Some nanorods are detached when methyl-terminated nanoparticles are used and the percentage of detached nanorods increases with increasing carbon chain length. In contrast, the nanorods do not detach from carboxyl-terminated nanoparticles. This study offers direct experimental evidence to molecular simulation prediction that nuclei display a confined morphology on a highly curved seed surface due to the difficulty of maintaining an unstrained structure and they readily detach from the surface during heterogeneous crystal nucleation. This study contributes a solution-based method for the making of nanorods.