Preparation And Research On Performance Of Bionic Cooperative Antifouling Coating

From theory and experiment,environment friendly marine anti-fouling coating is investigated.The main content is divided into four parts:Using low surface energy material polydimethylsiloxane(PDMS)as substrate,and combining with biomimetic technology,biomimetic micro-textured marine anti-fouling coating was prepared and it's anti-fouling performance was analyzed.Combining nanoparticles with impermeable anti-fouling agent,nanocomposite impermeable anti-fouling coating was prepared,and the anti-fouling properties and mechanism were investigated.Based on the synergism of anti-fouling principle of low surface energy,nanoparticles,impermeable anti-fouling agent,and biomimetic micro-texture,biomimetic synergistic anti-fouling coatings were prepared,and theirs anti-fouling properties and mechanism were disclosed.Adhesion behavior of bacterial particles on different walls was explored based on EDEM-FLUENT coupling calculation.Firstly,anti-fouling coating with cylindrical,cross,rib and groove biomimetic micro-texture on surface was prepared by photolithography and inverted-mode curing process,using low surface energy PDMS as main film-forming material.The effect of micro-texture on the apparent and anti-fouling properties of coatings was observed and investigated.Results show that,the coated surfaces have a height of 60?m,regular and well-structured micro-texture of cylindrical,rib,cross and groove shapes,respectively.The contact angle of coating surface increases with micro-texture,whereas the surface free energy decreases.The contact angle of the coating with cylindrical texture is the maximum,and the surface energy is the lowest,and the bacteriostasis rate reaches 50%.So the coating with cylindrical texture has the best anti-fouling performance.Secondly,combining various nano-fillers with impermeable anti-fouling agent,taking low surface energy PDMS as substrate,phenyl methyl silicone oil(PSO)as non-reactive impermeable anti-fouling agent,and adding ZrO₂,TiO₂and ZnO with particle size of 30 nm,nano composite impermeable coating was prepared,and the influence of different nano-particles on the mechanical properties of coating and the penetration rate of PSO was investigated.Results show that,the contact angle of the coating increases and the surface energy decreases when nano-ZnO is added to the coating.However,as adding nano-TiO₂and ZrO₂,the contact angle of coating decreases,whereas the surface energy increases.Nanoparticles in the coating can slow down the seepage rate of PSO in the coating effectively,and improve the mechanical properties and anti-fouling performance of the coating.In addition,the coating with nano-TiO₂has the slowest penetration rate of PSO,the highest mechanical properties,and 77%bacteriostasis rate.Then,combining various anti-fouling principles,the biomimetic synergistic anti-fouling coating with micro-texture was prepared by exerting the multi-synergistic effects of low surface energy PDMS,anti-fouling agent PSO,nano-ZnO,and biomimetic micro-texture.The influence of nano-ZnO content on mechanical properties and PSO seepage rate of the coating was studied,and the anti-fouling performance and mechanism of biomimetic synergistic anti-fouling coating were tested.Results show that,with the increase in nano-ZnO content in the coating,the contact angle of the coating increases,the surface energy decreases,and the surface hardness increases.The penetration rate of PSO on coating surface decreases with the increase in nano-ZnO content.The coating containing 10%ZnO have better mechanical properties and anti-fouling effect.For biomimetic synergistic anti-fouling coating with PSO,10%nano-ZnO and cylindrical biomimetic micro-texture,97%bacteriostasis rate is achieved,and the anti-fouling effect is more significant than anti-fouling coating with single factor,marine biofouling is prevented effectively.Finally,based on EDEM coupled with Fluent software,with the coupling method of continuous fluid medium with particle discrete element,the adhesion results of bacteria were simulated under the condition of elastic and rigid walls,walls with different elastic modulus and texture.Results show that,bacterial particles are more likely to desorb in the shear form from elastic walls than from rigid ones.The number of bacteria adhesion on rigid wall increases linearly with time,while the number of bacteria adhesion on elastic wall increases linearly at first and then tends to be stable with time.In this simulation,with the increase in elastic modulus of wall,the relative adhesion between bacterial particles and wall increases,the number of bacterial adhesion on wall increases,but the growth rate decreases slightly.Microtexture added to the wall can reduce the amount of adhesion of bacterial particles significantly.The wall with diamond and cylindrical texture has the best adhesion effect against bacterial particles,while the wall with cross texture has the worst adhesion effect against bacterial particles,and this is because the bacterial particles adhere to texture pits easily.