Load-Bearing Structure Inspired Cellulose-Based Aerogel With High Resilience and Water Tolerance

Cellulose-based aerogels possess satisfactory sustainability, porosity, and resilience, which are promising materials to replace traditional petroleum-based foams. However, the viscous aggregation formed between hydrophilic fibers and the pore collapse caused by weak support force pose challenges for their further applications. Here, a load-bearing structure-inspired cellulose-based aerogel is innovatively developed with excellent elasticity and water tolerance through surface-interface modulation. Specifically, cellulose and polyvinyl alcohol (PVA) form interwoven skeletons by non-directional freeze drying. Crucially, the rhamnolipid surfactant assists in forming stable and uniform bubbles, and drives the regularization of frame structure during the freezing process, promoting the construction of refined mechanical structures. Besides, the interfacial enhancement by esterification reaction of citric acid and the encapsulation by hydrophobic silane via chemical vapor deposition endow aerogels with better resilience and water tolerance. The as-prepared aerogels can withstand intensive compression cycle tests and possess the ability to rebound over 10 times underwater. Even after 12 h wet treatment, the strain and stress loss respectively decrease by ≈55.5% and ≈14% compare with the initial unregulated aerogels after 500 cycles of 80% compression. Surprisingly, they have excellent cushioning performance beyond expanded polystyrene (EPS) and expanded polyethylene (EPE) in simulated road transportation packaging applications, indicating their potential in new-generation cushioning materials.