Pure boron nitride nanotube thread-based woven textile for thermal neutron shielding with extreme thermal stability

Abstract

Long-distance space missions encounter a significant hurdle in the form of space radiation, which calls for effective radiation shielding materials to protect astronauts and critical equipment. It is in response to this challenge that we developed the first-ever example of pure boron nitride nanotube (BNNT) woven textiles. For this, we prepared wet-spun aromatic amide polymer (AAP) and BNNT (AB) composite threads using the lyotropic molecular self-assembly (LMSA) method. The 1D AB threads provide the necessary continuity and pliability to easily fabricate macroscopic 2D woven textiles. Finally, we successfully developed 2D BNNT woven textiles by applying the soft domain selective degradation (SDSD) process, which selectively removes only the thermally labile organic domain of AAP. This process ensures the retention of the 1D fibrous structure of the thermally stable inorganic domain of BNNT. The resulting pure BNNT woven textile exhibits thermal neutron shielding performance (0.48 mm？1) and outstanding thermal resistance (1350 °C), making it a promising material for space applications.