A robust and low-adhesion superhydrophobic quaternized chitosan-based film with hierarchical micro/nano structures

Maocheng Ji , Fangyi Li , Jianyong Li , Yinghua Qiu , Chuanwei Zhang , Sixian Peng , Jianfeng Li , Jia Man

School of Mechanical Engineering, Shandong University

Journal：《PROGRESS IN ORGANIC COATINGS》

Abstract：

Quaternized chitosan (QCS)-based films are garnering considerable attention owing to their multifunctional properties; however, their inherent hydrophilicity limits their application. In this study, a fluorine-free superhydrophobic surface for QCS-based film was fabricated using an easy and effective method. The film with hierarchical micro/nano structures (MN-surface) was fabricated by combining the template and spray methods. After modification with polydimethylsiloxane, the MN-surface showed excellent superhydrophobicity, with a water contact angle of 165.7° and a sliding angle of 4.2°. The air cushions captured by the hierarchical micro/nano structures reduced the contact area between water droplets and the MN-surface, giving it excellent self-cleaning ability. Additionally, the microstructures acted as a protective layer for the nanostructures, protecting them against damage during mechanical wear. Thus, the MN-surface exhibited remarkable mechanical robustness against sandpaper abrasion, tape peel-off, bending, stretching, and water flow impact. More importantly, it showed an excellent anti-adhesion effect on bacteria, thereby further lowering the risk of bacterial invasion. Consequently, the superhydrophobic QCS-based film opens up new possibilities for its application in diverse fields.

Keywords: Quaternized chitosan film ;Superhydrophobic surface ;Hierarchical structure ;Low-adhesion ;Mechanical robustness

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