Research On Fabrication And Superhydrophobicity Of Biomimetic Structure On Stainless Steel Substrate

As a kind of common metal materials, stainless steel is widely used in various fields due to the advantages of high strength, beautiful modelling, excellent corrosion resistance and ductility. In recent years, the stainless steel have widely used in the fields of automobiles, machinery manufacturing, shipbuilding, aviation industry and medical equipment, etc. However, with the constant improvement of the comprehensive performance requirements for the materials, the performance of the stainless steel itself can’t meet the demand. In order to endow the stainless steel surface of some special physical and chemical properties, the stainless steel surface modification has gradually become a research hotspot.Here, inspired by typical plant surfaces with super-hydrophobic character such as lotus leaves and rose petals, a superhydrophobic surface was achieved successfully by chemical etching technique, electrochemical deposition technology and laser processing technology. 304 stainless steelwas used as substrates and micro-nano hierarchical structure was obtained. What is more, the graphene bionic structure was applied to change the hydrophobic properties of the metal material surface. This is a new attempt and in promoting the development of hydrophobic modification on stainless steel surface.At the same time,the new attempt will also has important significance for the development of graphene and its potential application.The superhydrophobic surfaceswith micro/nano structure were achieved successfully on stainless steel substrate by chemical etching technique after modification by DTS(CH3(CH2)11Si(OCH3)3). When the volume of etching agent concentration of ferric trichloride, hydrochloric acid and hydrogen peroxide is(15: 1: 1vol%), the maximum water contact angle(WAC) obtained on stainless steel is 158°. The concentration of chemical etching agent play an important role on the micro nano structure and surface wettability of stainless steel. The etching time has the smaller influence on the wettability of surface structure. The frosting process on cold surfacewere observed on ordinary stainless steel surface and on superhydrophobic stainless steel surface, including droplet setting time and frost crystal growth position,etc. The results showed that the superhydrophobic surface has an excellent anti-frosting character compared to pure staining steel. This method could provide a facile, low-cost and stable route to fabricate a large-areas superhydrophobic surface with anti-frosting for application in various environment.Inspired by rose petals surface structure, the periodic micro column structure was preparedsuccessfully on stainless steel surface through laser processing technology.After transfer graphene film onto the stainless steel surface, the metal surface realize the transition from superhydrophilic surface to hydrophobic state, and the contact angle reaches128°. Considering the impact of test parameters such as scanning shape, laser power, scanning interval, laser linewidth and heat affected zone on the surface morphology. When the scanning interval is100μm and micro column diameter is 80μm.The bionic structureimitating the rose petals is prepared on stainless steel through laser processing technology on the stainless steel, and the wettability, microstructure and chemical composition of the prepared suface was also analyzed.A three-dimensional graphene structure was prepared on stainless steel surface by electrochemical deposition technique and the water contact angle reached 152°.Considering the effect of electrolyte concentration, deposition time, current density on the surface morphology of the nickel plated stainless steel. When the electrolyte solution with a mixture of nickel chloride(250g/L), boric acid(60 g/L)and sodium dodecyl sulfate(0.15g/L), the electrodeposition time is 5 min, the current density is5A/dm2 and the reaction temperature is 45℃.The nickel film with snowflake structure deposition on stainless steel surface. Here, nickel film as a catalyst,graphene success grows on stainless steel surface by chemical vapor deposition technology. The obtained graphene structure and nickel layer structure of samples were characterized by scanning electron microscopy. The quality and layers of graphene filmweretested by raman spectroscopy and the contact angle measuring was used to measure the hydrophobic properties of samples.