Self-Assembled Superlattices from Colloidal TiO2 Nanorods

The self-assembly of anatase TiO2 nanorods into 1D (ribbon), 2D (smectic, domino, honeycomb) and 3D (lamellar) liquidcrystalline ordered superlattices is a process that depends on the collaboration between evaporation dynamics and directional interactions. Herein, the roles of entropic depletion attractions and energetic dipole-dipole couplings between TiO2 nanorods in self-assembly process are particularly emphasized. Excess oleic acid surfactants act as depletion agents to induce the inter-rod depletion effect, and the origin of electric dipole moment along the longitudinal axes of TiO2 rods is theoretically authenticated by applying the Accelrys Materials Studio as a new strategy combined with Tasker's theory. These nanorod superlattices provided here may have great importance for tailoring new promising structures for photovoltaic application or exploring new inorganic liquid crystal materials.