Thermodynamic and kinetic analysis of silicone oil enhanced antifouling performance of poly(dimethyl-methylphenyl-methyltrifluoropropyl)siloxane coating

This paper presents an efficient and environmentally friendly antifouling coating that does not release toxic substances or damage marine ecology. In previous work, a novel of poly(dimethyl-methylphenyl-methyltrifluoropropyl)siloxane (PDPFS) was prepared. The excellent antifouling performance of PDPFS coating relies entirely on the wash of water flow, thus its static antifouling ability is limited. Silicone oil (SO) is introduced into PDPFS coating to further enhance its antifouling ability. Three SOs with the same viscosity are selected, namely methyl silicone oil (MSO), fluorosilicone oil (FSO) and phenyl silicone oil (PSO). According to thermodynamic analysis, none of three SOs are compatible with PDPFS, which is the basis for SOs to leach out from the PDPFS coating. Through kinetic analysis, SO can undergo phase separation and aggregation within the cured PDPFS coating. Then, three SOs are leached to the coating surface through interface gaps between cross-linked bodies by capillarity. Due to the different wettability of SOs on PDPFS coating, MSO and PSO leach upwards while FSO leaches downwards. The upward leaching of SO forms an oil film that prevents marine fouling organisms from firmly adhering, and even if they adhere, they can easily be removed from the surface together with SO under external forces. According to the antifouling performance test results, the antifouling efficiency of PSO/PDPFS coating is superior to that of MSO/PDPFS and FSO/PDPFS coating, and it increases from 23.39 % to 84.89 % with increasing O/P.