Facile Preparation And Application Research Of Superhydrophobic Coatings

Wettability is a very important surface property of materials,which can affect the usage of material to a large degree.Preparation of materials with special wettability or wettability modification of materials will broaden their application areas.Inspired by many natural superhydrophobic surfaces such as lotus leaves and water skipper,people have prepared kinds of superhydrophobic materials and have applied them to the area of surface self-cleaning,anti-fouling,separation of oil/water mixtures and anti-corrosion.It is normally needed to fabricate rough structure with the low surface tension materials'modification subsequently when prepare superhydrophobic materials.As a result,it is of great realistic significance for their wide application to simplify the preparation process of superhydrophobic materials and improve their physical stability.In this research,we prepared inorganic and organic micor-sized and nano-sized coatings through normal physical chemistry approaches and deposited them to different material surfaces to obtain hierarchal rough structure and achieved superhydrophobic coatings with the modification of non-fluorine hydrophobic modifiers.Moreover,these coatings were applied in self-cleaning,separation of oil/water mixtures and anti-corrosion.The main research work includes:(1)Firstly,we prepared micro-sized boehmite particle through hydrothermal process;secondly,the hydrophobicity modification of the coating was done by the reaction between non-fluoride hydrophobic modifier lauric acid with the coating;Lastly,the coating was deposited onto different material surfaces and the obtained superhydrophobic surfaces showed water contact angle higher than 150°and sliding angle smaller than 8°.Actually,these surfaces showed non-wettability of sorts of liquids with surface tension between 38.2–72.6 mN/m because of the rough structure of lauric acid modified boehmite(LAMB)material,which endowed LAMB with excellent super-lyophobicity.Moreover,LAMB can also resist the wettability of different hot liquids.These special wettability gave LAMB outstanding self-cleaning and anti-fouling performance and the coated surfaces all showed non-wettability with lots of contaminated liquids.LAMB also showed nice anti-corrosion and displayed super-lyophobicity with acidic and alkaline solution with pH values ranging from 1 to 14.More importantly,LAMB coating displayed excellent physical stability with cohesive reaction between the coating and surfaces due to the glue liquid,which also allowed it to performe very well in the sand-impingement test.(2)We prepared LAMC superhydrophobic coating through the reaction between the alcoholic solution of lauric acid and copper hydroxide nano-material that can be obtained in market.Then,we successfully sprayed it onto several 2-dimensional and 3-dimensional material surfaces to accomplish the superhydrophobicity modification.LAMC superhydrophobic material not only displayed superhydrophobicity in the air but also showed non-wettability with water under oil(water contact angle equal about 160°under hexadecane).Based on these,LAMC coated surfaces all showed excellent anti-fouling property and self-cleaning both in the air and under oil.When LAMC was deposited onto copper mesh,it can achieve the separation of different oil/water mixtures and the separation efficiencies of light oil and heavy oil were all higher than 99%and separation velocity higher than 7.0 L/(m~2·s),which meant a very nice separation performance.When LAMC was coated onto 3-dimensional porous sponge,it showed sorption of several oil contamination with high selectivity and the adsorption capacity of the coated sponges were no less than 50 times to different organic liquids,displaying extraordinary sorption performance.Meanwhile,LAMC also showed nice endurance to sand-impingement test owing to the binder.(3)With the help of hydrophobic acrylonitrile-butadiene-styrene copolymer(ABS),we prepared non-fluoride eco-friendly superhydrophobic material through an one-step process of spraying the dichloromethane solution of ABS.By changing the concentration of ABS in dichloromethane,we obtain the best preparation condition of superhydrophobic ABS coating(ABS-24)and we successfully accomplished superhydrophobicity modification on different surfaces through spraying it onto these surfaces.When ABS-24 was sprayed onto filter paper,we found that the micro-structure of the coating were hierarchal and porous with pore diameter less than the suspension liquid droplets in the surfactant stabilized water-in-oil emulsions.Thus,the ABS-24 coated filter paper was able to separate water-in-oil emulsions.It can achieve the separation efficiencies higher than 99.90%and separation velocity higher than 2000 L/(m~2·h)with different span 80 stabilized water-in-oil emulsions,displaying outstanding separation performance.Moreover,ABS-24 was very stable to organic liquid and it was possible for real usage.