Coral biomimetic PDMS marine antifouling coating based on the intrinsic antibacterial and fluorescent response synergistic strategies

The applicability of polydimethylsiloxane (PDMS)-based marine antifouling coatings is restricted by their limited mechanical properties and static antifouling capabilities. In this study, we have developed a coral biomimetic PDMS marine antifouling coating, designated as PDMS-DAF-x-AMC, which employs synergistic antifouling strategies based on intrinsic antibacterial and fluorescent response mechanisms. Here, ‘x’ represents the amount of 3,4-diaminofurazan (DAF) incorporated into the formulation. Hydroxyl-terminated polydimethylsiloxane was employed as the primary matrix with DAF serving as chain extenders, 7-amino-4-methylcoumarin (AMC) acting as the end-capping agent and zinc ions as the coordinating metal. The dosages of DAF are 0.0, 0.1, 0.2, and 0.3 g, respectively, while the dosage of AMC is consistently maintained at 0.03 g. The supramolecular interactions, including hydrogen bonds and coordination bonds within the PDMS network enhance the mechanical properties, adhesion strength, and self-healing capabilities. Furthermore, the inherent antibacterial activity of DAF, combined with the fluorescence response of AMC synergistically imparts the coating with superior fouling-resistant properties with a bacteriostatic efficiency exceeding 99 % and maintaining a minimum diatom density of 18 ± 11 diatoms mm⁻². Also, the low surface energy ranging from 21.11 to 24.86 mJ·m⁻² gave the coating excellent self-cleaning properties and promoted the fouling-release performance. This study aims to introduce an innovative design concept for the advancement of high-performance PDMS antifouling coatings through the incorporation of various environmentally sustainable biomimetic antifouling strategies.