Optimization Of Cellulose Electrospinning Process And Experimental Research On High Efficiency Filtration

With the rapid development of economy,environmental problems become more and more serious,and people need more and more fresh air.Electrospinning is a simple and rapid way to prepare nanofibers.The nanofibers produced by electrospinning have a fine diameter,high specific surface area and high pore filtration,so it has a very important application in the field of filtration.Cellulose as the most abundant renewable resource in nature contains huge commercial value.However,the use of cellulose is limited because it is difficult to dissolve in common organic solvents.In this paper,cellulose and electrospinning technology combined to manufacture cellulose nanofiber high efficiency air filtration membrane.The air filtration performance of the membrane was tested and analyzed,and it was used in a dehumidifier.To explore the dissolution process of natural cellulose with a new cellulose solvent DMAC/Li Cl.The electrospinning test of cotton cellulose solution showed that it could not be electrospun into fiber membrane.After analyzing the reasons,it is decided to improve its spinnability by adding spinning aid.Through experiments,it was that PVDF could be fused with cotton fiber solution,and the mixed solution could successfully electrospun fiber.The influences of spinning liquid concentration,spinning voltage,receiving distance and spinning time on the filtration efficiency and resistance pressure drop of the air filter membrane were investigated.The Q_F(Filter Quality Factor)is represented the comprehensive filtration performance.The higher the Q_F value is,the better the comprehensive filtration performance is.Univariate tests of spinning voltage and spinning time were designed to find the relationship between electrospinning parameters and filtration efficiency,resistance pressure drop and Q_F.Through SEM analysis of the morphology of the electrospun fiber membrane.Finally,it is found that the better performance electrospun fiber membrane must be the experimental group that achieves a balance between filtration efficiency and resistance pressure drop.Among them,the Q_Fvalue of the group with the best comprehensive filtration performance reached 0.053,the filtration efficiency reached 98.749%,and the resistance pressure drop was only 83.277 Pa.The parameters of electrospinning were optimized by orthogonal experiment with Q_F as the optimization object.Through orthogonal experiment,the influences of four electrospinning parameters on Q_F were obtained:cotton fiber concentration>Spinning voltage>Receiving distance>Spinning time.According to this order and in combination with the previous univariate test,the appropriate level was selected successively.Finally,the optimized electrospinning parameters are as follows:cotton fiber concentration is 1%,spinning voltage is 13k V,receiving distance is 7cm,spinning time is 1h.Using this optimized electrospinning parameters were used to measure the filtration efficiency of 98.078,resistance pressure drop of129.691Pa and Q_F value of 0.03.The filtration performance parameters are in line with the national standard.Considering that the electrospinning fiber deposition has a certain chance,and the value is higher than that of most test groups,it proves that the orthogonal test has a certain optimization effect.On the basis of high filtration efficiency and low resistance pressure drop,it is expected to have a large dust capacity.The dust capacity reflects the dust capacity of the air filter membrane.The test is to judge the dust capacity of the filter material by increasing or decreasing the weight of the filter material within a fixed time.The experimental results show that the speed of dust absorption of electrospun cellulose membrane is much higher than that of ordinary non-woven fabric,and its maximum dust capacity is about twice that of ordinary non-woven cloth.The test also found that the speed of dust shedding on the electrospun cellulose film is also greater than that of ordinary non-woven fabric substrate,which also indicates that the electrospun cellulose film is easier to remove dust than ordinary non-woven fabric substrate,and more suitable for secondary use.The innovations of this paper expressed in the two aspect:firstly,the electrospun fiber membrane was prepared from primary cellulose by electrospinning;secondly,the application of natural cellulose electrospun fiber membrane in the field of filtration can effectively filter particles with a diameter of less than 500nm.