Hierarchical interface engineering for advanced nanocellulosic hybrid aerogels with high compressibility and multifunctionality

The hierarchical combination of mineral and biopolymer building blocks is advantageous for the notable properties of structural materials. Integrating silane and cellulose nanofibers into high-performance hybrid aerogels is promising yet remains challenging due to the unsatisfied interface connections. Here, an interfacial engineering strategy is introduced via freeze–drying-induced wetting and mineralization to reinforce the hierarchical porous cellulose network, resulting in mineral-coated nanocellulose hybrid aerogels in a simple and consecutive bottom-up assembly process. With optimized multiscale interfacial engineering between the stiff and soft components, the resulting cellulose-based hybrid aerogels are endowed with lightweight (>0.7 mg cm⁻³), superior enhanced mechanical compressibility (>99% strain) within a wide temperature range, as well as super-hydrophobicity (≈168°) and moisture stability under high humidity (95% relative humidity). Benefiting from these superior characters, the multifunctional hybrid aerogels as effective oil/water absorbents with excellent recyclability, thermal insulators in extreme conditions, and sensitive strain sensors are demonstrated. This assembly approach with optimized interfacial features is scalable and efficient, affording high-performance cellulose-based aerogels for various applications.