Fabrication And Applications Of Micro-and Nano-scale Interfacial Materials On Metal Substrates With Special Wettability

Wettability is a fundamental property of a solid surface,which has a variety of practical applications in the fields of daily life,industry,and agriculture.Usually,the wettability of solid surfaces is governed by their surface free energy and surface geometrical structures.Superhydrophobicity,usually arbitrarily defined as contact angle larger than 150°,is special situation of wettability.Up to now,plentiful methods have been put forward and a sequence of techniques have been developed to fabricate superhydrophobic surfaces on various substrates.However,when involved with industrial production,low cost,simple procedures,high efficiency and mass production becomes the most important factors.Therefore,among all the methods and processes,the advantages of etching process in industrial application is apparently outstanding.In this work,we focus on the fabrication of superhydrophobic surface without using expensive ingredients and complex procedures.As metal is one of the most important engineering materials in the world,superhydrophobic surface on metal substrates shows more promise for future applications.The main content and conclusion are listed as follows:(1)An efficient,economical and eco-friendly route was reported to fabricate superhydrophobic films on engineering metal materials through simple displacement deposition.This method includes two simple steps with each duration as short as 1 second,which indicates the possibility of industrial large-scale production.In addition,these superhydrophobic surfaces show excellent reparability.The simplicity of the coating method makes it possible for us to take Cu or Zn objects of any reasonable size or shape and to make their surfaces extremely hydrophobic,which can also be expand to other metals.Solution-immersion process is not the only option,spraying and brush coating is also feasible,which indicates promising prospect of large-scale production in water-transportation and oil spill clean-up field.(2)A simple and rapid method was reported to fabricate superhydrophobic films on copper substrates via Fe3+ etching and octadecanethiol(ODT)modification.The etching process can be as short as 5 minutes and the ODT treatment only takes several seconds.In addition,the whole process is quite flexible in reaction time.The as-prepared copper materials show excellent superhydrophobicity,mechanical durability(e.g.,abrasion and ultrasonic rinse)and chemical stability(e.g.,immersion in acidic/alkaline solutions).Meanwhile,the superhydrophobic materials exhibit high selectivity in oil/water separation,which can quickly separate diesel and chloroform from water.The samples can also prominently prolong ice-over time with a long cycle life.Moreover,the facile approach can be easily scaled up for producing samples with any reasonable size due to no need for special equipment.Owing to simplicity of the method,excellent superhydrophobicity,outstanding durability and stability,the as-prepared superhydrophobic copper surfaces are quite promising for practical applications.(3)A simple solution-immersion technique was developed for the fabrication of a superamphiphobic surface on the copper mesh.Hierarchical structure composed of nanorod arrays was formed on the copper surface by an alkali assistant oxidation process;after fluorination,the surface became super-repellent toward water and several organic liquids possessing much lower surface tension than that of water,such as hexadecane.Such superamphiphobicity is attributed to the synergistic effect of their special surface chemicals and microscopic structures,which allows for the formation of a composite interface with all probing liquids tested.We also discuss the effects of surface chemical constituent and geometrical structure on hydrophobicity and oleophobicity;such information allows us to engineer surfaces with specific oleophobic behavior.Additionally,this method can also be applied onto zinc substrates.Through this method,we also obtained superhydrophobic surface on zinc plate.The fabrication process is so facile and time-saving that it provides an opportunity to construct a regenerative super-repellency surface.This study offers insight into the design of surfaces with specific wetting behavior and may open up an avenue for application in many industry fields.(4)A superhydrophobic and superoleophilic surface was fabricated on copper substrate for possible application in the field of oil spill clean up.The superhydrophobic surface was fabricated by boiling a sheet of copper mesh in CuSO4 aqueous solution for an hour Cu2O film was coated on a Cu mesh surface via a simple one-step chemical method without using any fluorine and silicon chemical reagents.The resultant Cu2O coated mesh surface was superhydrophobic and superoleophilic on account of its low surface energy.Besides,with short-time immersion in acid,the Cu2O coating can transfer into Cu.As the Cu coating still remained micro and nano scaled structures,it can be easily changed into superhydrophobic by simply modified with ODT.This is a very simple and facile route without much raw materials and complex process,which can be large-scaled produced.