Investigation On Antifouling Coatings For Ships And Its Evaluation Of The Effect Of Drag Reduction

When marine fouling organisms attach to a ship, they will accelerate corrosion of the vessel, increase the drag and fuel consumption. The traditional poison-release coating affect adversely the environment. Due to low surface energy, environment friendly, smooth surface and drag reduction performance, the fouling-release coating has the attention of scientists.In order to develop high drag reduction properties of the silicone fouling-release coatings, the research group designs the torque test device to study the relationship between structure of fouling-release coatings and its drag reduction properties. Self-polishing co-polymer(SPC),CDP and silicone fouling-release(FR) antifouling coatings are selected to evaluate the properties.11kinds of the silicone fouling-release coatings which are modified by powders are prepared and tested the properties.The results show that, compared with other two kinds of coatings, the surface of silicone fouling-release antifouling coating has low surface energy and high water contact angle. Besides, It provides a low-friction, ultra-smooth surface. The result of the single disk test shows the average drag reduction rate of FR with respect to S-7(SPC) is13.50%,and the result of double cylinder test is22.07%. The high drag reduction properties of FR is because of its high hydrophobicity and smooth surface. The results of testing panels in the sea show antifouling property of FR is worse than the other two kinds of coatings, but its foul-release property is better.The tests of11kinds of modified silicone coating show the powder of glass flake, nano-TiO2, smaller particle size of Al2O3(Al203-4) can improve the hardness of coatings. The powder of carbon nano-tube(CNT) and Al2O3-4will increase water contact angle, enhance the hydrophobicity and reduce the surface energy of the coatings. The powder of iron oxide red, glass flake, TiO2and CNT will reduce biological adhesion factor (Fi) of coatings, Then the testing panels in the sea confirm the results. The powder of CNT and Al2O3-4can enhance the drag reduction properties of silicone coatings because of the strengthen hydrophobicity. With the thickness of coating increasing, the friction torque coefficient of1-A9,2-A4coatings decrease. As a result of incrassation of elastomer in the coating, the strengthen flexibility of coating reduces friction between the coating and seawater, enhances the drag reduction properties.