Femtosecond Laser Micro/Nano Processing Special Wettability Functional Surface

As can be seen in nature,the contact between the solid and liquid phases produces a wettability phenomenon.Functional surfaces with special wettability have important basic research value and practical application prospects.Inspired by the biological surface of nature,by appropriately changing the chemical composition or constructing the micro-nano structure of the interface,the functional surface of special wetting properties can be obtained,which has potential application value in the fields of energy,sensing,biomedicine and so on.Femtosecond laser processing as a non-contact,pollution-free processing method,with a wide range of processing materials,high processing efficiency,good processing quality and a series of characteristics,while the processing process is often accompanied by changes in the chemical composition and content of the material surface,so it has unique advantages in the preparation of special wettability surfaces.By adjusting the femtosecond laser processing parameters,a rough micro-nano structure can be generated on the surface of the material,which in turn affects the photothermal properties and electrochemical properties of the material surface.In this paper,the preparation of special wettable functional surfaces is realized by femtosecond laser processing technology,and the process is simple and the performance is good.The main research contents are as follows:(1)Based on polyetheretherketone(PEEK)material,three surfaces with different structural morphologies were prepared by adjusting the scanning speed of femtosecond lasers,and the photothermal properties of four different morphological surfaces and the wettability of water,tea,milk and coffee were studied.When the speed of femtosecond laser scanning is faster,it has little impact on the wetting of the original PEEK substrate;when the speed of femtosecond laser scanning is slower,the original hydrophilic PEEK substrate will become superhydrophobic,and it has good superhydrophobic properties for other solutions,including tea,milk,and coffee,and also has good self-cleaning performance.In addition,the photothermal properties of the four sample surfaces,including the original sample,were tested separately,and it was found that the samples with slow femtosecond laser scanning speed showed significantly better photothermal performance than the other two samples with the same and faster scanning speed.In the course of experiments,we summarized the influence of femtosecond laser processing parameters on the micro-nano structure,wettability and photothermal properties of PEEK materials and explained their mechanisms.(2)Nickel foam with a graded rough structure was prepared by using femtosecond laser micro-nano processing technology as the substrate.Through a series of morphological structure characterizations,the surface microstructure,elemental composition and wettability of nickel foam before and after femtosecond laser processing were compared.Nickel foam is silvery-white as it is,with good hydrophobic properties and a water contact angle of about 125°.The laser-treated nickel foam is black,the surface oxygen content is slightly increased and rougher,the water contact angle is about 0°,and it has changed from hydrophobic to superhydrophilic.The electrochemical workstation was used to detect its performance as a glucose sensor,and the original nickel foam was compared,and it was found that the femtosecond laser treatment of nickel foam had better potential sensing ability for glucose,and the reasons for the improvement of its performance as a glucose sensor were analyzed.