Relevance between Marine Biofouling and Physical Properties of Porous Ceramics Coated with Oxide Powders

Abstract

Recently, the eliminating methods of red tide organisms has been at- tempted by filtering method using the porous ceramic bodies. The marine bio- fouling, however, can be developed on the outer surfaces of porous ceramic body after use for long period of time, decreasing the function of the porous bodies. In this paper, the effect of ceramic coating to porous ceramic body upon inhibiting marine bio-fouling has been examined. The ceramic powders tried as coating materials were Al2O3, TiO2, and ZrO2. In the primary stage about for one month, the amount of bio-fouling decreased with increased water absorp- tion rate of specimens. During the early stage, the bio-fouling was caused by mostly from light-weight organisms such as red algae or microbes. After two months later, however, the amount of bio-fouling increased with decreased sur- face roughness of the specimen due to larger fouling organisms such as barna- cle. The Al2O3 proved as the optimum coating materials among three ceramic powders to prevent the marine bio-fouling owing to offering lower water ab- sorption and higher surface roughness to the specimens. It was confirmed that the amount of bio-fouling could be reduced by controlling the water absorption and the surface roughness of the porous ceramic through the oxide coating without using the environmentally hazardous materials.