| Micro-nano fibers,which are widely used in air filtration,have very high specific surface area and porosity,but there is a contradiction between high filtration efficiency and low filtration resistance.At present,there are various kinds of methods for the preparation of micro/nano fiber membrane,and electrostatic spinning method can be in of the fibers in the fiber forming process,can greatly improve the membrane filtration adsorption performance,is the most is expected to solve the contradiction of high-efficiency low-resistance preparation technology,one of which the melt electrospinning because of its non-toxic,environmental protection and the magnet effect is one of the best polymer polypropylene fiber forming effect is very good advantage.It has a great development prospect in the field of air purification filter membrane preparation.So to ease air purification filter membrane is the contradiction between the high filtration efficiency and low filtration resistance,in this paper,the advantages of using differential electricity melt spinning technology,from the electrostatic spinning technique,membrane filter material modification to the post-processing three aspects to improve the performance of fiber membrane filtration,for efficient development of low resistance air purification of membrane preparation method play an important role,And the practical application of micro-nano fiber in the field of air purification has expanded a certain space.On the basis of summarizing the research of micro and nano fiber membrane,this paper focuses on the following points.(1)In order to alleviate the contradiction of high efficiency and low resistance of the air filter membrane,PP/electret master batch electret air filter membrane was prepared by melt differential electrospinning technology.The effects of electret master batch content and electret treatment on the morphology and filtration performance of the fiber membrane were studied.The results show that the addition of electret masterbatch and electret treatment can improve the filtration performance of the fiber membrane,and the quality factor of the membrane prepared can reach up to 0.3.040 Pa-1,which is 2.86 times of that of the membrane without electret treatment.(2)On the basis of alleviating the contradiction between high efficiency and low resistance of the filter membrane,in order to solve the environmental protection problem of disposable filter membrane recycling,the research on high performance and environmental protection air filter membrane was carried out.The high performance degradable PLA/electret master batch air filter membrane has been successfully prepared with a quality factor of 0.1150 Pa-1,which is 1.46 times of that of PLA/0%electret master batch fiber membrane without electret treatment,and the comprehensive performance of the filter membrane has been effectively improved.The PLA/2.0%master electret membrane with the best comprehensive filtration performance has a higher filtration efficiency of 99.4344%than the PP/0.9%master electret membrane with the best filtration efficiency of 92.8233%.The degradation rate of the fiber membrane in 0.01 mol/LNaOH alkaline solution reached 12.36%after 12 days.(3)Based on melt differential electrospinning electret parent electret air filter membrane,a new type of composite filter membrane with cavity structure is proposed,which breaks through the problem that the filtration efficiency and resistance of the traditional composite filter membrane increase exponentially with the increase of thickness.The effect of cavity gap size and fiber film orientation Angle on quality factor was studied deeply,and the flow field was analyzed by FLUENT.The results show that the cavity structure can improve the comprehensive filtration performance of the fiber membrane.When the cavity clearance is 3 mm,the comprehensive filtration performance of the fiber membrane is the highest,and the quality factor is 0.1522 Pa-1.Secondly,the cavity structure oriented composite filter membrane is prepared.When the orientation Angle is 30°,the quality factor can reach 0.1694 Pa-1.It provides a new idea for the research of the new structure of high efficiency and low resistance filter membrane.Finally,a kind of air purification and humidification device for the advanced filter cake and water membrane two-stage filtration is designed by adopting the melt differential electrospinning cavity oriented composite filter membrane,which can make full use of the filter membrane and has stable filtration performance.This device can meet the application requirements of specific places and expand the application range of the air purification humidifier.To sum up,based on melt differential electrospinning technology,high efficiency,low resistance and environmental protection electret master batch electret air purification micro-nano fiber membrane was prepared in this paper,and its performance was systematically studied.Secondly,the composite membrane with cavity structure was proposed,and the filtration mechanism was analyzed by experiment and simulation.Finally,a kind of air purifying and humidifying device with full use of filter membrane is designed.The research in this paper opens up a new idea for the application of melt differential electrospinning micro-nano fiber membrane in the field of air purification. |
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