Interfacial Regulation and Phosphate‐Siloxane Hybrid Networks Enable Regenerated Cellulose Aerogels for Multi‐Scenario Transport Packaging

A large barrier to replacing petroleum‐derived foams in transport packaging is the difficulty of simultaneously achieving high mechanical resilience, fire safety, and environmental durability in sustainable aerogels. Here, a regenerated cellulose (RC) aerogel is designed via interfacial regulation and hybrid crosslinking: phytic acid (PA) enables phosphate‐assisted crosslinking between RC and polyvinyl alcohol (PVA), while sodium lignosulfonate (SLS) stabilizes the foamed precursor. Subsequent hexadecyltrimethoxysilane (HTMS) chemical vapor deposition constructs a robust hydrophobic siloxane‐containing surface layer, yielding the silanized aerogel (S‐RPPS). S‐RPPS exhibits durable hydrophobicity with water contact angles of 140.7° (outer surface) and 137.2° (cross‐section), enabling rapid underwater compression‐rebound cycling without structural disintegration. It also delivers strong fire safety and thermal insulation, showing no ignition under a 600°C open flame and maintaining a surface temperature below 143.2°C within 3 min. Mechanically, S‐RPPS remains stable after 500 compression cycles at 80% strain (stress loss rate ≈ 6.6% and strain loss rate ≈ 8.1%), retains > 90% oil sorption capacity after 100 squeeze‐regeneration cycles, and maintains performance after one‐month exposure to harsh media. Overall, this work establishes a scalable strategy for multifunctional biomass aerogels targeting flame‐retardant thermal insulation and pollutant adsorption, aiming to mitigate fire hazards and leakage‐induced contamination during transport packaging.