Impact of model contaminants on surface active marine coating addtives

Marine coatings are often based on silicone resins, with further additives to inhibit biofouling or enable release of adhered species. The efficiency of additives decreases with time and particularly with exposure to common contaminants, such as oils. We have started to explore this for model PDMS/additive systems by studying changes in surface property via dynamic contact angle. These experiments reveal dramatic changes in surface property upon exposure to hydrocarbon oil and we propose to use NR on simplified models to elucidate the molecular origins of this change in surface property. We postulate that alkane contaminants may promote surfactant leaching from PDMS film either by swelling the matrix (osmotic stress) or by compatibilising the additive, enabling it to diffuse out more easily. NR experiments will isolate these effects, so helping to formulate better marine coatings.