Transparent cellulose films: Preparation, functionalization, and applications in food packaging

As the food packaging industry advances towards green and low-carbon solutions, developing sustainable, high-performance materials is essential to mitigate white pollution and enhance food safety monitoring. This review systematically summarizes the preparation strategies for transparent cellulose films, covering physical methods, chemical modification, and green dissolution-regeneration systems. It focuses on analyzing the regulatory mechanisms of different preparation routes with respect to transparency, mechanical properties, and functional characteristics. Building on this basis, this paper proposes the research concept of physicochemical structural regulation of cellulose, which emphasizes the precise optimization of cellulose's aggregated-state structure, surface chemistry, and interfacial properties. This approach aims to enhance the comprehensive performance of film materials, constructing a new generation of "efficient, stable, and multi-scenario adaptable" intelligent packaging. Furthermore, functionalization strategies such as in situ growth, composite loading, electrospinning, and layer-by-layer self-assembly are elaborated, and their mechanisms for endowing films with antibacterial, antioxidant, UV-shielding, and intelligent response properties are discussed. Despite their advantages, challenges regarding wet stability, the trade-off between transparency and functionalization, and large-scale production bottlenecks remain. Finally, the review outlines future directions-including green processing, multifunctional integration, and industrial scalability-to accelerate the transition of cellulose-based intelligent packaging from laboratory research to commercial application.