Super-flexible, thermostable and superhydrophobic polyimide/silicone interpenetrating aerogels for conformal thermal insulating and strain sensing applications

Soft and thermostable materials are crucial to applications in the fields of aerospace, wearable materials, and artificial intelligence (AI) in harsh environments. However, decided by the molecular structures, most soft materials are easy to pyrolyze at 100-200 degrees C, hindering developments in the critical technologies for such applications. In this work, through a rational slice/sphere dual-morphology microstructure design, a hydrogen-bonded polyimide/silicone aerogel is obtained with a two-step-gelling process. As rationally discussed with evidence, the recoverable air compression and the silicone sphere deformation contribute to the super-flexibility, with the low elastic modulus (0.155 kPa), high cyclic compressive strain (90%), and good fatigue-resistance (600 cycles at 50% strain). Additionally, the structure and components together endow the composite with light weight (0.14-0.16 g cm(-3)), low bulk shrinkage (less than5%), superhydrophobicity (water contact angle of 150.1 degrees), prominent thermostability (weight remains 90% at 474 degrees C), promising thermal insulating performance below 600 degrees C, and stable sensing ability at 300 degrees C. The efficient thermal insulation, sensible pizeopermittivity and endurance in a wide temperature window ( 196-400 degrees C) make it feasible for conformal thermal protection and strain sensors for aerospace, and AI applications under harsh conditions.

Automated summary

Soft and thermostable materials are crucial for applications in aerospace, wearable materials, and artificial intelligence in harsh environments. In this study, a hydrogen-bonded polyimide/silicone aerogel was obtained with a rational microstructure design, exhibiting super-flexibility, low density, low shrinkage, superhydrophobicity, and excellent thermal stability.