Cage aquaculture has gained significant attention in recent years in India to address nutritional security of the growing population. A major issue in cage aquaculture is biofouling, and its management accounts 10 to 25% of the total project cost. Non-polar polymeric materials, such as polyalkenes (polyethylene/ polypropylene) , are commonly used for cage construction. The current strategy to combat biofouling in aquaculture cage nets involves coating with binders or polymeric adhesives containing biocide s. These methods are disadvantageous due to excessive use of biocides, its leaching to the environment, increased weight of the cage net, and disposal after the culture. Nano technology offers efficient solutions to mitigate the biofouling issue in aquaculture cage nets. Aquaculture cage nets mainly fabricated polyethylene, which is a non-polar polymer . The surface of the polyethylene is need to be modified to incorporate nano biocides to combat biofouling. ICAR CIFT developed two methods to modify the polyalkene surfaces using conducting polymers like polyethylene and organo silane molecule ((3-glycidyloxypropyl)trimethoxysilane) (silane ) [1, 2]. Successfully embedded varied nano biocides like nano copper oxide, nano copper oxide – titanium oxide, nano carbondot - graphene, nano carbondot - titanium oxide, nano carbon dot –(CuO:TiO2) etc , over polyethylene surface modified with polyaniline / organosilane . These biocides were effective to contain the accumulation of biofoulers in the aquaculture cage nets. The study aimed to evaluate the biofouling inhibition efficiency of coating of nano copper oxide and oleamide o ver both polyaniline and organosilane coated over polyethylene. Nano CuO and oleamide treated sequentially over PANI and silane surface modified polyethylene aquaculture cagenets (PE-PANI, PE-Silane) . The CuO and oleamide respectively interacted with Si-O and C-O-C bonds through amide N-H in the silane- PE and in the case of PANI- PE both biocide strongly interacted through quinoid moiety of PANI . Surface morphologies of treated surfaces also showed uniform coatings and the introduction of oleamide made the surface of aquaculture cagenet more hydrophobic. Nano CuO (0.02%) : oleamide (0.04%) coated over PE-silane and / PE-PANI aquaculture cagenet exposed in the estuarine environment showed good biofouling resistance. The oleamide and nano CuO synergistically influenced to deter the micro and macro foulers.
Key words: Biofouling, aquaculture cage net, Copper oxide, oleamide .