Anisotropically Thermal-Protective Porous Ceramics Enabled by Nacre-Like Framework

Abstract

Ever more severe energy dilemma and unfulfilled demands for thermal protection applications have drawn a great interest in developing thermal protective materials. Though great progress is achieved by implementing several advanced micro-architectures, the conflict between thermal insulation and mechanical properties, along with the complex manufacturing process, remains the main obstacles for fabricating ideal integrated thermal insulation materials. Here, a scalable nacre-like porous ceramic is reported with a good combination of thermal insulation and mechanical strength (≈0.058 W m⁻¹ K⁻¹, 22 MPa) via a bottom-up film-to-bulk assembly. The well-aligned microplatelets constructed the nacre-like framework and produced porosity in between for thermal insulation while the mineral bridges between microplatelets connected and strengthened the whole framework. Besides, the structure-induced anisotropy of thermal conductivity on out-plane and in-plane directions provides the possibilities for heat management. Moreover, this material shows an excellent fire-resistance and maintained performance after fire. These structure-induced integrated superiorities made this material good candidate for complex thermal protection applications.