Preparation of a superhydrophobic coating with antibacterial and fresh-keeping properties using curcumin and chitosan

Surface fouling and bacterial contamination present significant challenges to daily life and industrial production, motivating the development of multifunctional surfaces with antifouling and antimicrobial properties. In this context, the development of multifunctional surfaces based on environmentally friendly green materials, which possess both superhydrophobic anti-fouling and highly efficient antibacterial properties, has become one of the approaches to address the aforementioned issues. In this study, superhydrophobic antimicrobial multifunctional coatings were successfully prepared by using environmentally friendly materials chitosan (CS) and curcumin (Cur) as antimicrobial agents, shellac and rosin instead of the traditional fluoride as low surface energy substances and adhesives, and nano‑calcium carbonate (Nano-CaCO₃) as hydrophobic particles. The multifunctional coating exhibits a contact angle exceeding 150° for both water and other liquids, demonstrating exceptional liquid-repellent properties and superior antifouling performance. Under an 80 g load, the coating withstands 45 cycles of sandpaper abrasion testing and 50 cycles of adhesive tape peeling testing. Furthermore, the composite coating samples show a 28% increase in tear strength and a 24% enhancement in puncture resistance compared to the pristine counterpart. The coating exhibits significant antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), achieving antibacterial efficiency rates of 99.1% and 99.3%, respectively. In strawberry preservation tests, the shelf life of the samples was extended to the sixth day. Composed of non-toxic and sustainable chemicals, the coating integrates superhydrophobicity, antifouling properties, and antimicrobial functionalities, thereby demonstrating broad applicability across diverse sectors, including paper protection, packaging, biomedical applications, and the food industry.