Selenonium-Catalyzed Dynamic Siloxane Exchange for PDMS-Vitrimer Coatings
Marine biofouling imposes substantial operational penalties on maritime assets, yet commercial silicone foul-release coatings rely on static, non-adaptive networks that cannot be reprocessed or repaired. This work introduces selenonium-salt-catalyzed dynamic siloxane exchange as a route to polydimethylsiloxane (PDMS) vitrimer coatings. The authors incorporate A16Se+ organoselenium catalysts into PDMS networks at loadings designated A16Se+xPDMS, enabling thermally activated siloxane bond exchange that confers vitrimeric stress relaxation, reprocessability, and high-temperature self-healing. Antibiofouling performance is benchmarked against pristine PDMS using colony morphology assays for Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, SEM imaging of bacterial adhesion after 3 h, Chlorella fluorescence adhesion quantification, zeta potential measurements, and 3-month seawater immersion panels. Reviewer 1 questioned the direct relevance of recyclability and high-temperature self-healing to marine antifouling and requested that surface elastic modulus and Pseudomonas antibacterial data be elevated to the main text. In response, the authors relocated scratch and self-healing results from Figure 5 to Supporting Information Figures S12 and S13, condensed the main-text discussion, and integrated surface elastic modulus data into Figure 4G and Pseudomonas antibacterial results into Figure 6A. The revised manuscript positions dynamic exchange as supporting evidence of network dynamics rather than as a primary antifouling metric, while foregrounding modulus and antibacterial performance as the application-relevant properties.