Research progress and current applications of biomass-based chitosan superhydrophobic composites

With the advancement of modern industry, the superhydrophobic properties of materials have found significant applications across medicine, energy, aerospace, and industrial manufacturing. Chitosan (CS), as a widely sourced and renewable biomass material, exhibits excellent biodegradability and biocompatibility. Its molecular chains contain numerous highly reactive functional groups, such as amino (—NH₂) and hydroxyl (—OH) groups, making it readily amenable to modification for the preparation of functionalised derivatives tailored to specific requirements. Superhydrophobic materials constructed from CS derivatives have garnered extensive attention in recent years due to their outstanding superhydrophobic properties and environmental friendliness. The characteristics of CS are introduced, the research progress in preparing superhydrophobic materials using CS derivatives as substrates via techniques such as surface cross-linking/grafting modification, sol-gel method, and dip-coating technique is systematically elaborated, and the application status of superhydrophobic materials in fields including self-cleaning, corrosion protection, oil-water separation, biomedicine, food, agriculture and industry is summarized. Building upon this foundation, the key issues existing in the current research field of CS-based hydrophobic materials are analyzed, and future research directions are identified, aiming to facilitate the scalable development and sustainable application of CS-based superhydrophobic materials.