Super-slippery silicone-based gel coating with a regenerative oil layer for long-term prevention of surface contamination

Polymer-based gel-type coatings, in which oil molecules are absorbed within polymer networks, have drawn attention as functional coatings to address fouling problems. However, surface drought caused by lubricant depletion limits the longevity of conventional gel-type coatings. In this study, a super-slippery long-chain entangled polydimethylsiloxane (LEP) gel that can self-regenerate a low-viscosity oil layer is proposed to enhance its long-term anti-fouling performance in both indoor and marine habitats. The proposed LEP gel coating can effectively prevent contamination from numerous liquids and protect aluminum surfaces from corrosion in seawater. Even when it was incubated with Porphyridium purpureum, marine red algae that readily stick to the surface, no biofilm was formed on the coated samples for 37 weeks. In field tests, no biological adhesion was observed on the coating surface which was applied to port structures and left for two summer months. This enhanced anti-contamination performance is mainly attributed to the dual protective barrier comprising the underlying polymer layer and regenerative oil layer. Due to special property of continuous self-regeneration of oil layer, the proposed LEP gel surface demonstrates much enhanced sustainability, compared to conventional gel-type coatings. Consequently, the long-term anti-contamination performance of the super-slippery LEP gel coating would pave the way for novel approach to its practical applications.