Abstract: Boron nitride nanotubes (BNNTs) are more thermally and chemically compatible with metal- and ceramic-matrix composites than carbon nanotubes (CNTs). The lack of an abundant supply of defect-free, high-aspect-ratio BNNTs has hindered development as reinforcing agents in structural materials. Recent activities at the National Research Council – Canada (NRC-C) and the University of California – Berkeley (UC-B) have resulted in bulk synthesis of few-walled, small diameter BNNTs. Both processes em…