| Surface corrosion and scaling is a ubiquitous phenomenon in nature,especially in the complex marine environment,which restricts the use of energy and the development of industry in the marine environment.For example,the corrosion and scaling behaviour of gathering pipelines,heat exchangers and downhole tools in the offshore oilfield industry.In the power grid industry,silicone rubber insulators are susceptible to contamination flashover in the humid marine environment during long term operation.These problems will bring great economic losses and security risks.Due to the unique wetting properties of superhydrophobic surfaces,their application in the field of protection has gained a lot of attention.Therefore,solving/mitigating corrosion and scaling problems in the marine environment through superhydrophobic surfaces has very important applications.In this paper,based on the existing research work,the effect of hydrophobicity on the corrosion resistance and scale inhibition performance was explored by modifying the object with low surface energy modification technology;then,the super-hydrophobic composite coating was prepared by adding nano-Si O2 particles into the polymer resin,and the super-repellent properties of the super-hydrophobic composite coating were investigated.The stability of super-hydrophobic composite coating in corrosion resistance and anti-scaling application was investigated,which provided a new scheme for the application of super-hydrophobic composite coating in surface salt protection in marine environment.The specific research contents and results of this thesis are as follows:（1）N80 steel sheet is commonly used in oil exploitation industry,was modified by surface fluorination,and the surface of N80 steel sheet with different roughness was obtained by pretreatment（polishing and sandblasting）,and then the effect of fluorination modification on the corrosion resistance and anti-scaling performance of N80 steel sheets was explored.The test results show that the low frequency impedance modulus of PF-N80 sample is 450Ω·cm2after 7 d immersion in the electrochemical test,which greatly improves the corrosion resistance compared with N80 sample;After 7 cycles of fast evaporation fouling test,the fouling amount of fluorination modified P-N80 sample decreased by about 42.55%compared with N80 sample.After 35 days of multi-field coupling fouling test,the fouling amount of PF-N80 and SBF-N80 samples was close to 0.5 mg/cm2 without obvious fouling.（2）Epoxy resin（EP）was used as the adhesive,nano-Si O2 was used as the filler,and a suitable amount of alcohol was added to dilute to obtain the EP-Si O2 composite primer.The micrometer-scale convex structure was obtained by spraying it on the surface of N80 steel sheet,and the superhydrophobic EP@Si O2 composite coating was obtained by spraying the fluorine-modified chain-like nano-Si O2 particles as a top coat on the semi-cured primer.The surface of the coating shows excellent superhydrophobicity due to its extremely low adhesion to the hot liquid,and the surface still retains some superhydrophobicity after 70times sandpaper polishing and 10 h water washing,indicating the stable mechanical properties of the coating;After immersion in aqua regia solution for 60 min and in 1 M sodium oxide solution for 12 h,the surface retains its superhydrophobic properties,indicating that the surface has excellent chemical corrosion resistance;After 35 days of electrochemical test,the low frequency impedance of the super-hydrophobic EP@Si O2composite coating is higher than 107 orders of magnitude,and the corrosion resistance is the best.After 50 h of rapid evaporation fouling test,the fouling amount on the surface of the coating is only 0.44 mg/cm2,which is about 98.00%lower than that of N80 steel sheet;after35 days of multi-field coupling fouling test,the coating did not show blistering,peeling,flaking and other phenomena,and maintained excellent hydrophobic properties,indicating that the coating has excellent anti-fouling properties.（3）Using acrylic resin（PAA）as a binder and nano-Si O2 as a filler,a PAA@Si O2composite primer was prepared,and a superhydrophobic PAA@Si O2 composite coating with superheat vapour rejection properties was prepared by two-step spray technology using fluorine-modified chain-like nano-Si O2 particles as a topcoat.The results show that the coating has excellent super-repellency to hot water and hot steam,and self-cleaning property to hot water and hot steam.The coating can still maintain the super-repellency to hot water after 100 times of tape stripping,heating at 300℃for 12 h,soaking in p H=1 to p H=13solution for 28 d,soaking in aqua regia for 12 h and soaking in 1 M Na OH for 12 h.The corrosion resistance of the PAA@Si O2 coating was investigated by neutral salt spray test,and the corrosion resistance of the coating was investigated by electrochemical impedance spectroscopy（EIS）.After 28 days of testing,the impedance modulus of the superhydrophobic PAA@Si O2 composite coating was about four orders of magnitude higher than that of the pure acrylic resin（PAA）coating;the scaling amount of the PAA@Si O2coating decreased by 93.62%. |
