Skin-Mimetic Surface Engineering: Synergistically Enhancing the Gas Barrier and Tuning Biodegradability of Bamboo Biomass Films

Lignocellulosic biomass films are promising green alternatives to petroleum-derived packaging. However, their high hydrophilicity and poor barrier properties remain critical challenges for commercialization. To address these critical challenges, herein, we propose a skin-mimetic surface engineering strategy to synergistically enhance the hydrophobicity and gas barrier properties of regenerated whole-component bamboo biomass films while feasibly regulating their biodegradability. Specifically, we constructed the skin-mimetic surface via an in situ ring-opening polymerization of epoxidized soybean oil (ESO), which was adsorbed onto the regenerated biomass film through soaking in an ESO solution. This skin-mimetic architecture endows the films with exceptional hydrophobicity, as reflected by a water contact angle of 115° and an 89% reduction in water absorption compared with that of the control sample. Furthermore, the skin-mimetic bamboo films exhibited enhanced barrier properties, showing 37–97% reductions in both oxygen transmission rate (OTR) and water vapor transmission rate (WVTR). The optimal barrier performance was observed at an epidermal thickness of 15 μm, with a WVTR of 63.4 g/m2·24 h and an OTR of 0.32 cm3/(m2·24 h·0.1 MPa). Besides, the epidermal layers allowed the modulation of the biodegradation rate under soil burial, with the film stability ranging from 10 to 150 days depending on the epidermal thickness. This work provides an efficient method to develop a high-performance, biodegradable bamboo-based packaging material.