Impacts Of Tourmaline On The Activity Of Marine Biology

To prevent the settlement and growth of marine organisms on submerged structures, such as oil rig supports, ship's hulls, antifouling coating is the most mature, economical and widely used method among all the solutions proposed throughout the history of navigation.Among all the different solutions proposed throughout the history of navigation, tributyltin self-polishing copolymer paints (TBT-SPC paints) have been the most successful in combating biofouling on ships. The widespread use of these paints has led to important economic benefits for many years. Unfortunately, the TBT-SPC systems affect adversely the environment. Furthermore, after an International Convention held on 5^th October 2001, parties to the convention are required to ban the application of TBT-based antifouling paints from 1 January 2003, and the presence of such paints on the surface of the vessel from 1 January 2008. Thus, the paint industry has been urged to develop TBT-free products able to replace the TBT-based ones but yield the same economic benefits and cause less harmful effects on the environment.So far, tourmaline mineral materials, depending on its special properties such as spontaneous polarization effect, have been regarded by many scientists all over the world. The aim of this thesis is to find out the impacts of tourmaline on the activity of marine biology in seawater and the adhesion characteristic of marine biology on antifouling coatings including tourmaline by a series of experiments, to prove the possibility of using tourmaline in antifouling paint.Though measuring the properties of tourmaline such as granularity, Zeta potential, negative ions release rate, choosing benthic diatom and bacterium as biofouling target, utilizing separately spectrophotometry and slab bacteria counting testing Chlorophyll a of benthic diatom and the gross of bacterial colony, evaluating the impacts of tourmaline mineral materials on activity of target and effect law, finally this thesis put forward effect mechanism model.The results indicate that tourmaline can restrain the growth of benthic diatom and bacterium, antifouling paint including tourmaline can also restrain their adhesion. This effect is more obvious with the increase of tourmaline content and the decrease of its granularity. Based on all of the experimental results, it could be deduced, when negative ions release rate of the coating including tourmaline reach 275ion/cm³, benthic diatom will not accrete any more on it.The author put forward three models to explain the mechanism of tourmaline restraining marine biofouling in this paper: surface electric field model, negative ions releasing model, dissolved oxygen model.