The Preparation Of Robust Superhydrophobic Materials And Self-cleaning Properties In Air And Oil

Lotus leaf has attracted people’s attention for it’s out of the silt but not imbrued.The reason is that its surface is superhydrophobic structure.Water droplet has great contact angle on the lotus leaf surface and form spherical shape so that they can readily roll away from the surface and remove dirt to keep the surface clean.With the deepening of the research on the superhydrophobic surface,the researchers found that the superhydrophobic surface is made up of two factors,one is the rough structure,mostly made up of micro/nano structure;Second,the low surface energy materials,such as fluoride,silicon and so on.Thus,there are two ways to fabricate superhydrophobic self-cleaning surfaces.One is to introduce hierarchical structure on a hydrophobic surface,and the other is to modify a micro/nanostructured surface with low surface energy materials.The methods to prepare superhydrophobic surfaces are also varied,including template method,etching method,layer by layer self-assembly method,and so on.At the same time,superhydrophobic materials have been widely used in the areas such as self-cleaning,ice prevention and liquid separation.However,because of poor durability of superhydrophobic materials and susceptibility to oil fouling,it leads the superhydrophobic materials applied to the real life become difficult.Aimed at the poor durability of superhydrophobic materials and susceptibility to oil fouling,we take the following two solutions:(1)An ethanolic suspension of perfluorodecyltrichorosilane-coated natural zeolite was coated on both hard and soft substrates including glass and filter paper.Adhesivewas used to bond the superhydrophobic coating to base materials to increase the durability of coating.Field emission scanning electron microscopy,atomic force microscopy,X ray diffraction and optical contact angle meter were used to characterize the morphology,crystal structure,surface elements,roughness and wettability of the surface.Results showed that it is the natural porous zeolite provided remarkable roughness and fluoride material reduced the surface energy lead to superhydrophobic;The coating has the good self-cleaning properties not only in air,also showed superhydrophobic under oil,what’s more,the cleaning performance is also very excellent in various solvents;The durability of the coating was greatly increased after the coating was adhered to substrates,it still has superhydrophobic after 30 cycles of sand paper test,indicating very high potential application value.(2)Firstly a layer of candle soot was deposited on base materials,and then a layer of methyl trichlorosilane was deposited on the surface of candle soot.Scanning electron microscope(SEM)and contact Angle measurement instrument were used to characterize the surface morphology and water contact Angle.Results showed that the hydrophobic candle soot particles formed coralloid structure on the substrate,and it doesn’t need low surface energy material modification can achieve superhydrophobic,besides,water static contact Angle can be as high as 161 °.The coating also showed excellent self-cleaning performance in the air and various solvents;The durability of candle soot layer was increased a lot after modified by methyl trichlorosilane,the surface structure hasn’t been destroyed after 20 times water scouring experiments.Thus,the coating can resist the damage of part of nature external force.It’s believed that it has potential practical applications.