The Study On Fabrication Of Fog Collection And Bubble Unidirectional Transport Janus Membrane By Ultrafast Laser

In the process of adapting to the living environment,the structure and function of organisms also evolve,forming micro-nano functional structures with special wetting characteristics.The preparation of micro-nano structures with special wettability to achieve similar functions and meet the needs of practical production and life is a problem to be solved.In this paper,the micro-nano structure with specific wettability is processed by combining the ultra-fast laser micro-nano processing and the intelligent bionic interface design principle,and the intelligent devices that meet the specific functional requirements were prepared.Firstly,the main components of ultrafast laser system were analyzed.The mechanism of interaction between laser and different substances was analyzed.On this basis,A hydrophobic/superhydrophilic membrane with adjustable fog collection rate was prepared,and the reason for the increase in the fog collection rate was analyzed with the help of the model.The superaerophobic/aerophilic foam copper with unidirectional transport of underwater bubbles was prepared by laser scanning,and the feasibility of underwater gas collection was verified by experiments.The details were as follows:?1?The basic concept of intelligent bionic interface was explained.The development history and research status of fog collection and underwater bubble unidirectional transport were systematically analyzed.?2?The performance difference between nanosecond laser and femtosecond laser, laser system,optical system components and control system were studied.The interaction principle between laser and material was analyzed from two aspects:laser with metal and organic polymer.?3?Combined with the scientific problem that the flexible intelligent material and the fog collection rate cannot be adjusted,the flexible PDMS Jauus of fog collection rate can be adjusted was prepared by using ultra-fast laser processing and hydrophilic reagent modification,the arbitrary and reversible adjustment of fog collection rate can be achieved by unidirectional stretching of the Jauus membrane.The water droplet and fog collection experiments of Janus membrane under different strains were studied by using the flexibility organic membrane.Compared with the original state,both the water droplet passage rate and the fog collection rate were significantly improved.At the maximum strain of 200%,the fog collection rate increased by 67%.By constructing a model to qualitatively analyze the reasons for the increase of fog collection rate caused by stretching,and combining with the microscopic morphology of the stretched state membrane and the quantitative calculation of mechanics,it is concluded that the fog collection rate of the 200%strain sample increases by about 79%,which is in good agreement with the experimental results.Through the flexible and repeatable experiment of organic membrane,the application possibility of intelligent Jauus membrane was verified.?4?Based on the importance and research status of bubble control in the water environment,this paper presents the Janus membrane for spontaneous unidirectional transport of underwater bubbles by hydrophobic treatment and nanosecond laser ablation of copper foam,it can achieve unidirectional penetration of underwater bubbles from the laser treatment side to the other side,but not the opposite direction,that is"bubble diode".The gas collection performance of copper foam under different laser scanning was systematically studied.It was found that when the laser scanning speed was 1m s^-1,the collection rate was the maximum of15 mL cm^-22 min^-1.The dynamic process of unidirectional bubble transport was studied from two aspects:transport mechanism and stress analysis.Finally,the practicability was further verified by the color reaction between the carbon dioxide gas collected by copper foam and the alkali solution with phenolphthalein.Based on ultrafast laser preparation with special wetting properties of flexible PDMS Janus membrane and copper foam Janus membrane were used for fog collection and underwater bubbles unidirectional transport,it can be provide design ideas and feasible research plan for fog regulation,microfluidics,gas collection,controllable gas reaction and the potential application of biological medical fields.