Lignocellulosic Films: Preparation, Properties, and Applications

Lignocellulosic films (LCFs) have garnered significant attention due to their unique combination of flexibility, functionality, cost-effectiveness, and eco-friendliness. Defined as thin, compact, and continuous sheets with a typical thickness in the range of 10-100 μm, LCFs have been used in various fields, including packaging, flexible electronics, energy storage and harvesting, sensing, water treatment, and agriculture. Based on preparation strategies and chemical compositions, LCFs can be categorized into cellulose derivative films, regenerated cellulose films, nanocellulose films, hemicellulose films, lignin-based films, and whole lignocellulosic biomass films. While previous reviews often focus on specific types of LCFs, e.g., nanocellulose films, a comprehensive review covering all categories and their recent advancements is still lacking. This review aims to address this gap by providing a thorough overview of the basic structure and chemistry of lignocellulosic biomass, preparation strategies, functionalization methods, and the broad spectrum of applications of LCFs. Additionally, it examines the environmental and economic feasibility of LCFs and identifies strategies to overcome existing challenges, offering valuable insights for advancing the field and supporting future innovation in sustainable material science.