Bioinspired robust yet regenerable nanofibrous polymer brushes for broad-spectrum antifouling

Abstract

Polymer brushes with mechanical robustness, strong substrate adhesion, regenerable (self-healing) properties and antifouling performance are highly desirable for preventing engineering alloy surfaces from long-lasting biofouling in broad applications from biomedical facilities to marine industries. However, it remains challenging to simultaneously satisfy the above requirements through a simple strategy. Herein, we report a class of coral-like nanofibrous zwitterionic polymer brushes with a uniform monodisperse size distribution via a simple radical polymerization confined in nanoporous alloy substrates based on a simple combined hard/soft strategy. The hard nanoporous substrates shield the soft polymer brushes from being peeled off. Despite removing the superficial polymer brushes, the nanoporous substrates can regenerate fresh polymer brushes under the swelling effect. The polymer brushes consist of cellulose nanofibrils (CNF) and zwitterionic sulfobetaine methacrylate (SBMA), where the former improves mechanical properties by almost three times and mechanical stability in water shearing environments while the latter enhances antifouling performance. The hydrogen-bonded interfacial water film confined in zwitterionic polymer brushes enables the low adhesion force and formation of energy and physical barriers, showing excellent broad-spectrum antifouling action (above 98%) towards various bio-foulants, including proteins, bacteria, and cells. Our findings offer a new sight into the chemical and physical mechanisms of underlying foulants prevention. This study provides a simple strategy for the simultaneous realization of antifouling, mechanical robustness, strong substrate adhesion, and self-healing of polymer brush coatings on engineering metal surfaces, making it envisioned for prospective applications.