Creating stable dispersion of boron nitride nanotubes (BNNTs) is vital to effectively translate their superior thermal, chemical, and mechanical properties to macroscopic assemblies. These properties are desirable for a variety of applications, including fabricating robust films and fibers for effective heat management.  Cellulose nanocrystal (CNC)-templated BNNTs are essential to obtain chiral nematic liquid crystals of BNNTs for producing aligned films and fibers.  In this study, we demonstrate that pectin, a polysaccharide naturally found within the cell walls of plants, is effective in stabilizing BNNTs in water.  This is achieved through the hydrophobic and π-π interactions, and the steric stabilization of BNNTs by pectin.  Particularly, we determined an optimum mass ratio of BNNTs:pectin = 1:2 in creating stable aqueous dispersions of BNNTs.  We characterized the dispersion quality and yield of BNNTs through UV-vis absorbance measurements.  The colloidal stability of BNNT dispersions was evidenced by the light scattering effects as defined by the Tyndall effect.  The phase behavior of chiral nematic liquid crystals of BNNTs/CNC dispersions was characterized through rheology and optical microscopy.  Additionally, scanning electron microscopy was utilized to evaluate the morphology of BNNTs/CNC films.  This work lays the foundation for our future studies in manufacturing thermally conductive films and fibers through liquid phase processing for a variety of situations where thermal management is essential, such as electronics, protective coatings, and fabrics.

Dispersion, liquid crystalline phase behavior, and assembly of pectin-wrapped boron nitride nanotubes in cellulose nanocrystal suspensions

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.