Preparation And Properties Of Superamphiphobic Aluminum Surfaces

Superamphiphobic surface is an extreme wettability surface that relies on air film to resist water and oil infiltration.It has large potential applications in the field of national defense,industry,agriculture and daily life due to the functions of self-cleaning,corrosion resistance,anti-icing,fluid drag reduction,and attracted extensive attention and research in recent years.In this paper,a two-step chemical reaction method was used to construct the micro/nano composite hierarchical structures on commercial aluminum surfaces,and then the superamphiphobicity（ie,superhydrophobicity and superoleophobicity）was obtained by low surface energy modification.We use contact angle measuring instruments,field emission scanning electron microscopy（FE-SEM）,Energy dispersive spectrometer（EDS）,X-ray diffractometer（XRD）and X-ray photoelectron spectroscopy（XPS）,techniques to study the influence microscopic topography and surface composition on wettability.Based on the actual application environment,a series of simulation tests were designed to evaluate the durability of as-prepared superamphiphobic aluminum surfaces.Finally take some measures to improve the property of aluminum.The main contents and conclusions of this works are as follows:The hierarchical rough structure was constructed on aluminum surface by non-corrosive salt solution included Cu²⁺and Cl^-etching and boiling water bathing.Then the rough structure was modified by low surface energy molecular groups to achieve superamphiphobbicity.Wettability tests show as-prepeared surfaces can resists liquid infiltration with a surface tension greater than 27.5 mN/m.FE-SEM analysis shows that the etching process and the water bath process form micro step-like structures and nano sheet structure on aluminum surfaces,respectively.XPS analysis showed that the low surface energy molecular group containing fluorine was deposited on the surface by self-assembly.Large-scale sample preparation results show that the fabrication method can achieve uniform super-repellency in a large sample.Durability tests show that as-prepared superamphiphobic Al surfaces can resist the destruction of surface composition and microstructure by water impacting,and the superamphiphobicity is basically unchanged after drying.Sand abrasion cause surface morphology damage and increased adhesion force of the abraded surface.In the liquid immersion environment,the air film on the superamphiphobic surface can resist the infiltration of the liquid to the surface,effectively reducing the speed of modifier coating dissolution and aluminum surface corrosion.Thermal insulation test shows that as-prepared surface can maintain super-repellency under 240℃.Multiple peeling causes the damage of surface microstructures and the decrease of the low surface energy effective group.The superamphiphobicity obtained by this method can keep more than one year,which can well meet the requirements of practical applications.In view of the inadequacy of the superamphiphobic aluminum surface,it was modified to liquid-infused porous surfaces（Slips）.The lyophobic range of modified surface was significantly enlarged,which can resist the wetting of the organic liquid with the surface tension greater than 18.4 mN/m.In addition,Slips has self-repairing capabilities,mechanical damage will not cause the super-repellency decrease.The disadvantages of Slips are weak corrosion resistance and dust resistance.