Barnacle adhesion to silicone fouling release coatings.

摘要

Silicone fouling release coatings are now accepted as a biocide free alternative for controlling biofouling on ship hulls and man-made structures. This research contributed knowledge with respect to an understanding of barnacle adhesion to silicone coatings. The thesis provides a short historic perspective of the material properties that impart fouling release to a surface. It then describes the experimental methods used in this research (static immersion in seawater and hard fouling adhesion strength, atomic force microscopy and high-speed digital video and static digital imagery).; The results are presented in four sections: (1) barnacle adhesion as a function of species, age, and environmental interactions where thickness of the silicone coating was the independent variable, (2) differences in adhesion strength of organisms from different phyla, (3) barnacle adhesion strength to silicone elastomers with different silicone fluid additives (4) high speed video of barnacle detachment showing viscous fingering characteristic of confined viscous fluids and soft solid materials, and the development of a mechanical model of barnacle adhesion to silicone coatings.; Results are discussed in context with the modulus of barnacle adhesive being less than the silicone substrate, the viscous nature of the interface and the dynamic nature of the adhesive protein. This places the adhesive of barnacles on silicones in a category similar to that of marine gastropods, that of a non-Newtonian viscoelastic adhesive gel. The view of barnacle detachment from silicones as a viscoelastic process will help in understanding functional relationships between adhesion and surface characteristics. A simple conceptual model of barnacle adhesion on silicone is presented to provide a basis for appropriate mathematical modeling of detachment.; The results of this research have practical implications to the optimization of fouling release coatings. Factors such as coating thickness and the addition of specific silicone fluids have been shown to affect performance. Possible negative environmental effects of released silicone additives in the marine environment have not been investigated and should be addressed.