Recyclable and high-performance metal coordination bonds cross-linked polybenzimidazole aerogels for flame retardancy, thermal insulation and dyes adsorption applications

Aerogels made from high-performance polymers have attracted great interests in recent years. However, traditional chemical crosslinking process is complex, and makes it difficult to adjust the skeleton structure of aerogels and achieve polymer recovery. Herein, polybenzimidazole aerogels with good mechanical property, uniform porous structure, and specific surface area as high as 660.23 m2/g are facilely prepared through metal coordination. The excellent thermal stability, high flame resistance, and low thermal conductivity make the aerogels good candidates for flame-retarding and high-temperature thermal insulating materials. Notably, the reversible metal coordination crosslinking permits the recycling of aerogels, which has not been realized in previous high-performance polymer aerogels yet. Moreover, the aerogels can repeatedly adsorb dyes from wastewater because of their large specific surface area, good chemical resistance, and abundant polar imidazole groups. This work is expected to provide a simple approach to recyclable, high-performance, and multifunctional polymer aerogels.