Antifouling Polymers with Room-Temperature Self-Healing and pH-Sensitive Controlled Release

Abstract

Polymer-based coatings provide an effective approach for controlling biofouling through low-toxicity mechanisms. Nevertheless, the antifouling performance of conventional coatings remains limited by the initial burst release of antifoulant and mechanical degradation during service. In this work, we develop an antifouling polymer featuring room-temperature self-healing and pH-responsive controlled release. The incorporation of dynamic disulfide bonds imparts an autonomous self-healing behavior, allowing the material to recover 98.8% of its tensile strength. In addition, β-thiopropionate linkages undergo acid-triggered cleavage, enabling the controlled release of capsaicin at the fouling interface. During the initial 6 h, the release remained nearly undetectable at pH 8.5 but was significantly triggered at pH 5, reaching a rate of 122.1 μg cm−2 day−1. Compared with polymers that either lack capsaicin or have capsaicin physically blended into them, the resulting material exhibited superior antifouling activity against marine bacteria. These findings establish a viable design paradigm for next-generation antifouling coatings that combine intrinsic self-healing with environmentally triggered antifoulant release.