Abstract

Boron nitride nanotubes (BNNTs) are an emerging nanomaterial with promising properties. Several applications of BNNTs include new flame retardant materials and elevated temperature corrosion protection for aerospace applications. BNNTs have a 1D tubular nanostructure, and are inherently noncytotoxic, mechanically robust, and have extraordinary chemical and thermal stability. The purpose of this project was to rheologically characterize BNNTs in aqueous DNA solution in order to predict their rigid rod behavior at semi-dilute concentrations. Rheology is the study of the flow of matter, and using rheology data to calculate rigid rod behavior can have theoretical liquid crystalline phase behavior implications. Due to BNNTs’ inability to be dispersed in water (as BNNTs are hydrophobic), DNA was selected as an effective stabilizing agent for BNNTs in solution. Three types of DNA-wrapped BNNT dispersions were prepared for rheological analysis, and the excess unbound DNA was removed via a precipitation method. Our rheology results show Newtonian behavior for all three samples (indicating that they were in dilute regimes), where the steady shear viscosity of each type of sample remained constant as a function of shear rate. Future work will focus on the rheology of DNA-BNNT dispersions at varying concentrations in order to determine the distribution of average aspect ratio (length to diameter ratio) of BNNTs in the dilute regime, and also predict the rigid rod behavior of BNNTs in the semi-dilute regime.

How to Cite