(620d) Phase Behavior and Aligned Assemblies of Lyotropic Liquid Crystals of Cellulose Nanocrystal-Templated Boron Nitride Nanotubes

Utilizing liquid crystals of one-dimensional (1D) boron nitride nanotubes (BNNTs) is a promising approach to manufacture strong, multifunctional films and fibers with improved alignment and properties. Cellulose nanocrystals (CNCs) are renewable, rodlike nanomaterials that are known to form lyotropic liquid crystals. In this work, aqueous dispersions of BNNTs were stabilized by carboxymethyl cellulose nanofibers (CM-CNF) via noncovalent complexation. The individually dispersed BNNTs were then incorporated into aqueous dispersions of CNCs and the phase transitions of BNNT/CNC mixtures with increasing concentrations of nanorods were studied using polarized light optical microscopy and rheology. Additionally, we utilized the wet spinning method to obtain solid fibers from BNNT/CNC mixtures and measured the resulting mechanical properties. Fiber spinning from liquid crystals of BNNT/CNC mixtures can potentially better translate the alignment and properties of nanorods to solid assemblies, which will lead to developing BNNT-based applications in many areas ranging from thermal management materials to multifunctional textiles.