Anti-cracking coating with wrinkled morphology for enhancing oxidation resistance of carbon-based fiber aerogel

Abstract

In our previous work, ceramic precursor coating with wrinkled morphology was obtained by cross-linking gradient generated from ultraviolet and cross-linking agent to improve the anti-cracking of the coating in the pyrolysis. However, the cross-linking gradient was difficult to control with ultraviolet and cross-linking agent. Herein, a simple method was proposed to form the wrinkled morphology of the coating by the steady-state temperature gradient field generated from constant temperature pre-treatment. Composite aerogels were prepared by pyrolysis at high temperature. The thermal insulation and oxidation resistance of the composite aerogels were explored. The heat transfer behavior within the composite aerogels was analyzed by simulation. The results showed that the stored strain of wrinkled morphology counteracted the shrinkage of ceramic precursor polymer during the pyrolysis, which prevented the cracking of the coating. Compared with the aerogels of our previous work, the composite aerogels of this work demonstrated improved thermal insulation and oxidation resistance.