A superhydrophobic textile inspired by polar bear hair for both in air and underwater thermal insulation

Polar bears have special hairs with porous microstructure and hydrophobic surface, which help them keep warm in both cold air and water. Due to the large difference in temperature and heat transfer process of aquatic and terrestrial environments, it is quite difficult for typical thermal insulating materials to maintain ideal insulation in air and underwater at the same time. To tackle this problem, we report here a superhydrophobic porous textile mimicking the outstanding thermal insulating properties of polar bear hairs. Fibers used to weave this textile are fabricated by a freeze-spinning method, providing them aligned porous microstructure. After a superhydrophobic surface treatment, the obtained textile with porous microstructure and superhydrophobic surface is capable of capturing air in its multi-scale porous structure, promising an excellent thermal insulating ability in both air and water environments. Our study paves a way for the bioinspired engineering of thermal insulation textiles both in air and underwater.