Study On The Dynamic Adhesion Properties Of Laser Ablated Special Wettability Surfaces In Air And Water Media

Wettability is an important property of solid surface.The dynamic regulation of material surface wettability can be achieved by changing its micro-nanostructure and chemical composition.The special solid/liquid/gas interface contact status of superhydrophobic/superhydrophilic/hybrid special wettability surfaces provides a variety of applications in air and underwater media.In this paper,laser texturing micronanostructure on metal surface combined with surface modification process is uesed to obtain superhydrophobic/superhydrophilic/hybrid special wettability surface,and its dynamic adhesion characteristics in air and water media is explored.The main results are as follows:1.The preparation process of laser selective texturing process to obtain superhydrophobic/superhydrophilic/hybrid wettability surfaces and the law of wettability changes are studied.The micro-nanoscale rough structure is constructed on stainless steel surface by ultraviolet nanosecond laser,combined with surface modification process and one more laser selective removal process to obtained the preparation of superhydrophobic/superhydrophilic/hybrid special wettability surface.The influence law of laser processing parameters and chemical modification process on superhydrophobic/superhydrophilic properties are discussed.2.The dynamic adhesion-bounce characteristics of droplets on hybrid superhydrophobic-superhydrophilic special wettability surface in the air is explored,and an ultrahigh speed gyrating droplet generation method via torque transmission on this special wettability surfaces is presented.The surface is fabricated by selective laser texturing on aluminum alloy substrates,and with the existence of wettability pattern,the rotating momentum provided by the rotating substrate which was coupled to impact droplet,resulting in ultrahigh speed gyrating droplets.The regulation of ultrahigh gyrating speed of bouncing droplets could be controlled by pattern size and the substrate driving speed,and the hyper gyrating speed can reach 96700 rpm.The torque transfer mechanism is an efficient energy conversion method,which combines the transformable kinetic energy of the impact droplet and driving speed of the rotating substrate,resulting in ultrahigh speed gyrating droplets.3.The dynamic properties of bubbles and bacteria adhesion of the special wettability surface in the water is studied.The hierarchical micro-nanostructure is textured by picosecond laser,with surface modification to obtain hybrid special wettability surface which is superhydrophobic in air and superaerophilic underwater simultaneously.The bacterial adhesion experiment shows that regardless of 10 min,50min,or multiple dip-extract process,when the sample is extracted from the bacteria solution,the surface the surface is clear without bacteria adhered or a small amount remained.The surface with excellent resistance to bacteria adhesion bacteria adhesion verifies that air layer and hierarchical micro-nanostructures on the superhydrophobic surface have come together to comprise the antibacterial mechanism.