Microfluidic Exploitation of Liquid Crystal Properties of Boron Nitride Nanotubes and Enhancing Neutron Shielding with Aligned Structure

Boron nitride nanotubes (BNNTs) are cylindrical nanostructures characterized by alternating boron and nitrogen atoms. Unlike carbon nanotubes (CNT), BNNTs are electrically insulating and exhibit high thermal stability and neutron shielding capabilities. Their unique tubular structure enables the formation of 1D arrays, which can achieve a nematic liquid crystal phase, ideal for fabricating high‐density structures. However, the widespread application of BNNTs has been hindered by challenges in purifying and dispersing high‐purity BNNTs. This study aims to exploit the liquid crystal properties of BNNTs by generating high‐purity BNNT dispersions through a series of dispersion and purification processes. Furthermore, this study utilizes microfluidics technology to encapsulate the BNNT dispersions. Using this approach, the transition of liquid crystal phases in relation to BNNT concentration is efficiently examined. This process results in the production of high‐density BNNT films characterized by pronounced anisotropy, which in turn provides significant thermal neutron shielding effects. Liquid crystal phases of boron nitride nanotubes (BNNTs) are discovered using a microfluidic device to create double emulsions, increasing core concentration to observe phase transitions. This approach highlights BNNT's orientation on spherical surfaces and facilitates the creation of a high‐density, aligned BNNT film with strong neutron shielding properties, demonstrating its potential as a high‐performance material.