Research Of Shell Surface Topography Based On Ship Green Antifouling

Material surface microtopography has influence on its antifouling property, which is receiving more and more attention. Marine molluscs, as a kind of marine organism, is subject to the threat of settlement of marine fouling organisms inevitably. But the biofouling on shell surfaces of different kinds of molluscs is different. This thesis set out from the research of shell surface topography, established the parameters system of describing shell surface topography characteristics and compared the shell surface topography characteristics of different positions, the shell surface topography characteristics between ridge and groove and the similarities and differences between the shell surfaces of different kinds of molluscs which have different biofouling conditions, with the aim of developing a kind of ship green antifouling method based on antifouling properties of surface topographies..A method of measuring shell surface topographies was proposed. When need to measure a kind of shell surface, firstly, a sampling condition was determined by observing surface topography of this kind of shell with optical microscope; Secondly, surface topography of this kind of shell was measured for many times at the sampling condition determined by first step using contact measuring profilometer; thirdly, surface power spectrum and cumulative power spectrum of measuring results were calculated, judging whether the sampling condition determined by first step is appropriate based on the distribution of power spectrum value in these two spectrums; lastly, if the sampling condition determined by first step is appropriate, surface topography of this kind of shell will be measured at this sampling condition using contact measuring profilometer, if not, a another sampling condition was determined and the second and third step were repeated until obtain a appropriate sampling condition, measuring this shell surface at this sampling condition. The method of judging whether a sampling condition is appropriate was certified. The results showed the sampling condition determined by this method is appropriate.The parameters system of describing shell surface topography characteristics was established based on current researches of the relationship between material surface microtopography and its antifouling property. The shape error of measuring data was removed by separating measuring data with two-dimensional biorthogonal wavelet transform, selecting biorthogonal wavelet bior6.8 as wavelet base and selecting the method of symmetry boundary extension to extend boundary. The presented example validated that more reasonable evaluation results of surface characteristic parameters can be obtained after shape error being removed by two-dimensional biorthogonal wavelet transform. Furthermore, the program of calculating evaluation parameters of shell surface topography was complied.The shell surface topography characteristics of different positions and the shell surface topography characteristics between ridge and groove were compared using univariate method. Also, the similarities and differences between the shell surfaces of different kinds of molluscs which have different biofouling conditions were compared. The comparing results showed that the surface topography characteristics of different positions of one of five kinds of shells selected are not different significantly; for two kinds of shells selected, the surface topography characteristics of Scapharca broughtonii between ridge and groove are different, the surface topography characteristics of Chlamys nobilis between ridge and groove are not different significantly; comparing with the shell surface of Chlamys nobilis which has bad biofouling condition, the shell surfaces of Dosinia japonica,Cyclina sinensi and Ruditapes philippinarum which have good biofouling condition are more smooth and have less amount of pit.