Controllable Fabrication Of Stable Superhydrophobic Surface And Its Application Research

In order to exploit surface wettability,many different substrates,including metal,carbon felt,PU sponge,have been used for controllable fabrication of surface with different wettability,based on the bionic simulation of natural phenomena and the theory of wettability.Surface micro-/nano-dual structures and low surface free energy are the two key factors for fabrication of superhydrophobic surface.In consideration of the two factors,and combining with the superhydrophobic phenomena in nature,many different methods have been used for preparation.By SEM,EDS,XRD,XPS,AFM,TGA,FTIR,Raman,goniometer system,electrochemical workstation,universal mechanical tester and so on,surface characterizations were analysised,and then the surface morphology,structure,composition,wettability,corrosison resistance were confirmed.The results show that these surfaces exhibit excellent chemical stability,self-cleaning,anti-corrosion,anti-icing,anti-wear performance,and separation oil/water,removal oil from water properties.The main contents and conclusions are listed in the following:(1)Micro-/nano-dual sturctures have been fabricated on different metal substrates,including zinc,aluminum,iron,copper,through etch,chemical replacement,electrochemical deposition.Then,after annealing treatment,the surface wettability changed,showing superhydrophobicity.By the study of various experiment parameters,the optimal conditions have been found,and then the ideal superhydrophobic surfaces were prepared.During the preparation processes,there was no organic modifier used,which was one of the highlights.In general,the introduction of organic modifier will restrict the metals’ inherent properties,and also cause environmental pollution.The as-prepared superhydrophobic surfaces exhibit outstanding chemical stability,corrosion resistance,anti-icing property,and abrasion resistance.As is reported,due to the annealing treatment,which generates oxides and intermetallic compounds,changes the surface wettability.This is very important for the study of surface wettability,and the annealing treatment insteading of organic modifier,also offers new ideas for fabrication of superhydrophobic surface.(2)By immersion carbon felt into 10 m M 4-(Heptadecafluorooctyl)aniline solution for24 hours,then rinsed with ethanol and drying in the air.After that,the modified carbon felt exhibited superhydrophobicity and superoleophilicity;the water contact angle on the surface was higher than 150°,and the organic contact angle on the surface was almost 0°.This modified carbon felt can be used for separation oil/water mixture and removal oil form water.In addition,this carbon felt showed excellent fire resistance;when the carbon felt dipped with ethanol was ignited,the ethanol burned out,however,the carbon felt keep the initial shape without change.By TGA analysis,even at 1000℃ temperature,the mass of the carbon felt was without loss.What was novel about this modified carbon felt,was that it was equipped with superhydrophobicity,superoleophilicity,and fire resistance.As a result,it possesses promising commercial value for handling organic solvent which is flammable and combustible.(3)By immersion the kitchen sponge into dopamine solution,the surface exhibits superhydrophilicity;however,after immersion with 10 m M1 H,1H,2H,2H-Perfluorododecanethiol(PFDT)solution for 24 hours,the surface exhibits superhydrophobicity and superoleophilicity.Its absorption capacity for oil or organic solvent,such as chloroform,toluene,hexane,diethyl ether,ethyl acetate,peanut oil,is about 28-59 times as large as its own weight.This modified PU sponge can be used for separation oil/water mixture,and also removal oil from water,no matter the density of the oil or organic solvents is higher or lower than water’s density.(4)In view of the widely application field of the superhydrophobic/superoleophilic materials,it is of utmost urgency that developing easier,faster and more convenient methods for preparation superhydrophobic/superoleophilic coatings.Here,high density polyethylene(HDPE)resin was dissolved into xylene solvent at 120℃,then dipping ethanol into that suspension,then the superhydrophobic/superoleophilic solvent is prepared.The as-prepared solvent can be used in many different substrates to obtain superhydrophobic/superoleophilic surfaces,such as glass,metal mesh,and PU sponge.These as-prepared superhydrophobic/superoleophilic surfaces exhibit excellent chemical stability,self-cleaning property and corrosion resistance,and also can be effectively used in the field of separation and removal oil/water mixture.The advantages of this superhydrophobic/superoleophilic coating are few restrictions,simple preparation,and mass production.