(739d) Silver Nanowire Liquid Crystals: Phase Behavior and Aligned Films

Inorganic nanowires have innumerable potential commercial applications in opto-electronic and biomedical devices due to their optical, electrical and, in some cases, antimicrobial properties. Many applications require bottom-up assembly of aligned nanowires over large areas. We report the formation of aligned films from liquid crystalline dispersions of silver nanowires produced by the microwave assisted polyol process. The liquid crystalline phase transitions were dependent on the solvent, the fraction of spherical reaction by-products, and the aspect ratio of the nanowires. The spherical nanoparticles resulting from the reaction were found to facilitate nematic demixing, and shear was found to further separate the nanowires and nanoparticles. The rheological and morphological characteristics of isotropic, biphasic, and liquid crystalline dispersions were studied using a rotational rheometer and an optical microscope equipped with a shear cell. The alignment in the final films, as measured using Raman spectroscopy and scanning electron microscopy, was found to be a function of the shear rate and dispersion concentration.