Template Fabrication And Liquid-Solid Contact Characteristics Of Superhydrophobic Conical Pillars

Superhydrophobic surface has high application prospects in self-cleaning,corrosion resistance,friction reduction and drag reduction,non-destructive transfer of liquid,anti-fog,anti-freezing and frosting,so it has long been a research hotspot of experts and scholars.Among them,super-hydrophobic conical pillars can produce droplet pancake bouncing phenomenon,which greatly reduces liquid-solid contact time,and has great application potential in anti-icing.However,the existing processing methods of dense superhydrophobic conical pillars are few,and they generally rely on expensive equipment and complex process flow,which makes it difficult to process in large areas.In order to fabricate superhydrophobic cone arrays simply,efficiently and cheaply,this paper proposes that superhydrophobic cone arrays can be fabricated on aluminium substrates by using nanosecond pulsed laser energy distribution near Gaussian space,and then fabricated on aluminium substrates by grain boundary/dislocation hydrochloric acid preferential etching technology.Using this technology,superhydrophobic conical pillars can be fabricated on aluminium substrates by replication process.At the same time,the shape,size and surface micro-morphology of superhydrophobic cone-cylinder arrays were studied under different laser processing parameters,and the effects of shape,size and droplet parameters of superhydrophobic cone-cylinder arrays on liquid-solid contact characteristics were studied.The superhydrophobicity of polymer conical pillars,which were fabricated by submillimeter cone-hole arrays of aluminum matrix covered with micro-nanostructures,was about 163 degrees after modification with fluorosilane.With the increase of laser processing power P,the superhydrophobic conical pillars show a changing trend from needle shape?shape angle is about 139 degrees?to straight cone shape?shape angle is 180 degrees?,and the larger the bottom diameter D,the larger the laser processing power required to form a straight cone shape.In addition,the height of superhydrophobic conical pillars is determined by both laser processing power P and bottom diameter D.The liquid-solid contact time t_contact and jump index Q of superhydrophobic conical pillars with different shapes and sizes were investigated by means of high-speed camera.The results show that the superhydrophobic conical pillars with bottom diameters ranging from sub-millimeter?180 micron?to millimeter?1260 micron?can produce droplet pancake bouncing phenomenon;with the increase of shape angle?,the critical bottom spacing S of droplet pancake bouncing becomes larger;for the superhydrophobic conical pillars with specific shape and size,droplet cake can be produced in a larger droplet volume range.For a specific volume of droplets,the pancake bouncing of droplets can be produced in a larger We number range.On the basis of improving the process,a large area superhydrophobic conical pillars was successfully prepared,which proved that the process was simple and efficient,and could be prepared in a large area,laying the foundation for large-scale industrial preparation.On this basis,a large area superhydrophobic conical pillars with a size of 80 mm×80 mm was successfully fabricated,which laid the foundation for large-scale industrial application.