Designing biodegradable and antibacterial cellulose-based superhydrophobic packaging materials via large-scale self-assembly

Unbiodegradable petroleum-based packaging materials have posed a significant threat to the environment and human health, forcing the exploration of alternatives. Inspired by the charge-secreting layer of Sandcastle worm and the asymmetric wettability of lotus leaf, we successfully developed a dual biomimetic cellulose-based packaging material (CW@(CT)₁₀). This material was achieved through an electrically charge-controlled layer-by-layer self-assembly of chitosan and titanium dioxide nanoparticles (TiO₂ NPs), followed by functionalization with carnauba wax (CW). The material achieved commendable mechanical properties and abrasion resistance, rendering it highly stable and durable. Benefitting from the rough surface with nanostructures and low surface energy, the CW@(CT)₁₀ showed a high water contact angle of 152.14°. The superhydrophobic surface reduced the bacterial adhesion, which integrated with the electropositivity of chitosan, endowing the materials with a 100% antibacterial ability to Staphylococcus aureus and Escherichia coli. Fruit antimicrobial tests and degradation studies in the natural environment demonstrated that CW@(CT)₁₀ kept fruit bacteria-free for 5 days and were completely biodegraded within 100 days. Notably, this work introduced a facile strategy for scalable production of a sustainable, inexpensive, durable, and environmentally friendly material, showcasing immense potential applications in food packaging.

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