Biofouling is the process by which objects placed in the marine environment are populated by marine animals as soon as they are placed in the ocean. It is costly to remove and also can greatly affect the operation of equipment such as buoys and seismic sensors as the level of biofouling increases. There are commercial products available to eliminate bio-fouling but these are very toxic to the environment and require re-application over the life of the object.
CSIRO have developed a process (cold spraying) which produces an anti-biofouling coating (copper oxide particles) on polymer sleeves which can be used to cover sensors, cables chains etc. and reduce the problem dramatically. The process involves the dispersal of metallic particles onto the surface of the polymer. Trials on the polymer (polyurethane) used in seismic streamers (sensors used in geophysical exploration for oil and gas) have shown this product to be very effective, keeping the biofouling load to less than 5% of an untreated material The testing periods were in excess of 12 months. Given that many buoys and channel markers have to be removed on an annual basis to be cleaned, the cost savings, over the life of these devices could be enormous.
In this work we look at the distribution of the copper oxide particles on and into the polymer surface. Secondary and backscattered imaging is used to characterise the surface. A combination of optical microscopy as well as secondary and backscattered imaging combined with EDS and EDS mapping is used to characterise the depth profile of the copper oxide into the polymer. Although the copper oxide particles only embed into the sample approximately 10 – 20 µm into the sample EDS analysis shows copper present to a depth of approximately 1 mm.