Analysis of Self-Polishing Antifouling Paints Using Rotary Experiments and Mathematical Modeling

Abstract

A detailed mathematical model for a self-polishing antifouling paint has been developed. The important rate-influencing steps, dissolution of pigment particles, hydrolysis and erosion of the active polymer binder, effective diffusion in the leached layer, and external mass transport of relevant species, were all included. The aims have been to produce a tool for estimating paint lifetimes at various seawater conditions and paint compositions, for possible product optimizations, and for supporting the development of novel and environmentally friendly antifouling paints. Experimental data for model verification, such as polishing rates and extent of pigment leaching, were obtained using a laboratory rotor. Simulations performed for different rotary speeds and temperatures matched experimental data for two of the three paints investigated. In the last case, the disagreement between model and experiment was explained by significant water swelling of the hydrolyzed polymer. The modeling tools developed are applicable to other types of self-polishing antifouling paints than the ones investigated here.

Release and detection of nanosized copper from a commercial antifouling paint

“…Release of biocides from surfaces painted with antifouling paints is controlled by biocide chemistry, hydrodynamics, temperature, salinity, pH, microbial biofilm (Kiil et al, 2001(Kiil et al, , 2002Valkirs et al, 2003), and as shown here, painted material. When the mini-bars were removed from waters for sampling, we observed slight swelling of wood mini-bars.…”

“…(3) and (4)) (Ferry and Carritt, 1946;Kiil et al, 2001;Singh and Turner, 2009). In oxygenated water, Cu þ may be rapidly converted to cupric ion (Cu 2þ ) Kiil et al, 2001;Valkirs et al, 2003).…”

“…Fouling organisms are undesirable on hulls of ships and boats because they increase drag, and thus reduce fuel economy, and speed, and maneuverability of vessels (Kiil et al, 2001;Valkirs et al, 2003). Inorganic and organic copper (Cu) compounds have long been employed as biocidal agents, and have found use in antifouling (or bottom) paints to prevent colonization of vessel hulls by fouling organisms such as barnacles, tube worms, and algae (Omae, 2003;Turner, 2010).…”

Progress of marine biofouling and antifouling technologies

“…This results in cleavage of the TBT portion from the copolymer, and releases the biocides into the water [74]. Once many TBT portions have been cleaved, the partially reacted brittle polymer backbone can be easily washed off by the moving seawater, which exposes a fresh coating surface (Figure 7(a),(b)) [74,78]. The hydrolysis process provides a low hull roughness (about 100 μm), so as not to increase the resistance of the ship's hull [1].…”

Designing biomimetic antifouling surfaces

“…Rotor testing, in which paint samples are attached to a cylinder that is rotated at high speed in sea water, is commonly used for testing AF paints. The total run time of such tests is at least two months, but typically three to four months (Kiil et al 2001). Trentin et al (2001) have compared the results of rotor testing with extended exposure testing for conventional and selfpolishing paints containing cuprous oxide as biocide and found that laboratory tests proved to be significantly shorter, with a reduction in time from several years for field tests to just a few months and days for laboratory tests.…”