Laser Micro-Fabrication Of Super-Wettability Functional Surface And Performance Study

Biomimetic super-wettability functional surface has an important application prospect in self-cleaning surface anti-pollution and anti-corrosion,oil-water separation material interface,non-uniform wettability patterned surface for water collection,etc.However,the existing processing methods still have some problems,such as complex preparation process,low efficiency,lack of environmental friendliness and poor applicability.In this paper,an efficient and green preparation method based on laser micromachining was proposed.By adjusting the micro morphology and chemical composition of the surface,the super-wettability surfaces were prepared on the aluminum and glass substrate,and the experimental study of oil-water separation and water collection were carried out.The main contents include:By using laser processing machine,the oil-water separation mesh with micron scale rough structure was prepared efficiently.Combined with low surface energy solution modification and atmospheric pressure cold plasma modification,the superhydrophobic and superolephilic surfaces and superhydrophilic and underwater superhydrophilic surfaces were obtained on the aluminum foil substrate.This method with simple process and environmental friendliness does not need complicated large-scale equipment.The wettability,micro morphology and chemical composition of the surface of the aluminum mesh were characterized,and the gravity driven vertical oil-water separation experiment was carried out to study its oil-water separation performance.Taking the insoluble stratified mixture(light oil water and heavy oil water)as the research object,the performance analysis was carried out including three aspects: the oil-water separation efficiency of different types of oil-water mixtures,and the water content of oil after separation,water resistance of superhydrophobic-super olephilic surface and the oil resistance of superhydrophilic-underwater superolephobic surface.The results show that the oil-water separation efficiency of the functional surface with extreme wettability can reach 99%.In order to improve the applicability of laser micromachining method to other materials,the laser-induced backward transfer technology was proposed to rapidly transfer the target aluminum metal to the glass substrate,forming the metal layer surface with micron scale level rough structure.Combined with low surface energy solution modification and laser marking technology,the superhydrophilic patterns with complex shape were fabricated on the superhydrophobic surface.In order to study and compare the water collection ability of different surfaces,water collection experiments were carried out on glass,aluminum substrate,superhydrophilic surface,superhydrophobic surface and superhydrophobic-superhydrophilic wedge shaped array patterned surface.The results show that the water collection efficiency of superhydrophilicsuperhydrophobic patterned surface is higher than that of superhydrophilic,glass,aluminum and superhydrophobic surfaces,which are increased by 781%,331%,80 % and 53 %.