Robust and fibrous silicone/phenolic hybrid aerogels with devitrification resistance at elevated temperature

The fragility of aerogel is inherited from the bead-like structure, where the fine interconnections between these spheres act as weak points under load. Herein, aerogels with tailored fibrous structures were proposed to offer mechanical properties that surpass those of raw material by order of magnitude. Wherein, sodium alginate derived nanoribbons and fibrous template were progressively exfoliated in the wake of hydrogen bonding self-assembly and solvent-induced differentiation respectively. Interconnected nanofibrous architecture, which enabling efficient load transfer and stress distribution, endowed the silicone/phenolic (SiR/PR) aerogels with ultra-high compressive strength. Given facile ambient pressure drying technology and exceptional compressive strength (9.2 MPa), fibrous SiR/PR aerogels performed superior among reported ablative aerogels. Additionally, considering the uniform distribution of phenolic pyrolyzed carbon within the matrix, aerogel escaped from devitrification up to 1400 °C, thereby preserving fibrous morphology and larger specific surface area after annealing. This strategy for constructing microfibrous aerogels will pave the way for the robust fibrous aerogel with devitrification resistance.