Silicone-Based Lubricant-Infused Slippery Coating Covalently Bound to Aluminum Substrates for Underwater Applications

Abstract

Wetting of solid surfaces is crucial for biological and industrial processes but is also associated with several harmful phenomena such as biofouling and corrosion that limit the effectiveness of various technologies in aquatic environments. Despite extensive research, these challenges remain critical today. Recently, we have developed a facile UVgrafting technique to covalently attach silicone-based coatings to solid substrates. In this study, the grafting process was evaluated as a function of UV exposure time on aluminum substrates. While short-time exposure to UV light results in the formation of lubricantinfused slippery surfaces (LISS), a flat, nonporous variant of slippery liquid-infused porous surfaces, longer exposure leads to the formation of semi-rigid cross-linked polydimethylsiloxane (PDMS) coatings, both covalently bound to the substrate. These coatings were exposed to aquatic media to evaluate their resistance to corrosion and biofouling. While the UV-grafted cross-linked PDMS coating effectively inhibits aluminum corrosion in aquatic environments and allows organisms to grow on the surface, the LISS coating demonstrates improved corrosion resistance but inhibits biofilm adhesion. The synergy between facile and low-cost fabrication, rapid binding kinetics, eco-friendliness, and nontoxicity of the applied materials to aquatic life combined with excellent wetting-repellent characteristics make this technology applicable for implementation in aquatic environments.

Performance of environmentally friendly, liquid-infused coatings against biofouling: evaluation of macrofouling and microbially induced corrosion in freshwater environments

“…In both cases, defects within the coatings may also serve as attacking sites for chloride ions and the onset of pitting corrosion. As iUV-PDMS successfully prevented corrosion in previous studies 49,60,61 we suspect that the lower amount of surface hydroxy groups on carbon steel may prevent a thorough anchoring of the PDMS chains in the process, compromising the quality of this type of coating on steel. Noteworthily, all other coated samples showed a reduced current density compared to the uncoated reference throughout the entire potential range probed in the experiment.…”