Preparation Of Superhydrophobic Ship Steel Surface And Its Antifouling Of Halobios Adhesion

Ship is the most important tool when human develop and use the ocean. However, people inevitably suffer the serious problem that marine organisms may adhere to the ship. People are used to use anti-adhesion coating to eliminate fouling organisms since it can release toxic heavy metal ions, which, surely, can seriously pollute the environment. Bionics research found that most organisms in the ocean can resist a variety of marine organisms’adhesion with its special surface topography."Shark skin" effect breaks people’s traditional view that the rough surface does not have anti-adhesion properties, laying the foundation for the use of superhydrophobic surface in anti-adhesion fields. This method, based on the theory of biological anti-adhesion, won’t release toxic substances and is efficient.This thesis is about the study of the most commonly used ship material Q235A ship steel. We combine laser processing with nanoparticles coating to build a superhydrophobic surface with biomimetic micro-nano structure. We use static immersion experiments and dynamic erosion experiments to test its performance of anti-adhesion of marine organisms. The main study results are as follows:1. Taking Q235A marine steel as base material, we built three kinds of micro-structure—Dot, line, grid—using laser processing, and paint the antirust coating. We use orthogonal experiment to study the effect different dilution ratio, spraying distance and spraying time have on antirust thickness. The results showed that when the spraying distance was60mm, spraying time was3s and the dilution ratio is4:3, the film thickness reach31μ.2. Under the same pitch, the contact angle of the sample grid is maximum, followed by the straight linear sample and the contact angle of the matrix sample. As the spacing increases, the contact angle of the sample matrix is gradually reduced and the roll angle increases; however, the contact angle of the grid and linear samples both increases first and then decreases, while the roll angle decreases first and then increases. The contact angle of the sample grid that have a spacing of200μm is up to156.2°, while its roll angle is only3.55°. 3. Through the laboratory culture of algae fluid, put the sample into the algae fluid and test. Take out the sample after15days, use layer separation technology of photoshop to calculate the attachment area of chlorella. We find that under the same spacing, grid sample has the least attachment area, followed by linear sample and the matrix sample. The stronger the hydrophobicity of the sample surface is, the smaller amount of the adhesion is.4. Fix the sample on the stirrer and place it in seawater, then stir it at a linear velocity of10knots, then test the adhesion strength of Chlorella of the sample surface. The results showed that the sample with a micro-structured surface has significant lower adhesion strength than the sample with polishing surface. What’s more, with the decrease of the roll angle of the surface, the desorption proportion increases. Therefore, we can draw the conclusion that preparing a surface of smaller the roll angle is helpful to the desorption of attached Chlorella and improve the anti-adhesion properties of the surface.This study shows that Cassie model superhydrophobic surfaces have stronger anti-adhesion properties than Wenzel model superhydrophobic surfaces. This study provides the ship’s anti-adhesion of marine organisms with new methods and technical support.