Ultralight and Elastic Polyimide Microtube Aerogel via Airflow-Induced Spinning.

Flexible thermal protection is of great significance in fields facing various environments such as aerospace and electric vehicles. Elastic aerogels with micro-nanofibers as the base unit effectively solve the force-thermal compatibility, optimized the contradiction between mechanical strength and thermal insulation performance, and solves the risk of fragile aerogel. In order to develop elastic aerogels with lower density and better thermal insulation properties. Here, the first one-step preparation of ultralight polyimide microtube aerogel sponges (PMAS) using airflow-induced spinning is reported. PMAS consists of a large number of structurally controllable microtube, resulting in ultralight density (≈50 mg cm), ultralow thermal conductivity (37 mW m·K at 25 °C), and excellent elasticity and fatigue resistance, with no significant attenuation of the maximum stress after 1000 cycles of compression at 80% strain. In addition, PMAS has temperature-invariant dynamic mechanical stability and an operating temperature range from 77 to 573 K. These superior properties enable PMAS to be ideal choice for thermal insulation in extreme environments, thermal runaway in batteries, adsorption and gas filling. Airflow-induced spinning fills the gap in the industrial-scale preparation and material compatibility of microtube, while also providing a promising solution for the universal preparation of microtube structures.