Research On Electrospinning Micro-nano Fibrous Membrane And Its Performance

With the development of society,water pollution of organic matter is also more and more serious,such pollutants as hormones,dyes and toxic waste seriously affecting the survival and development of mankind,therefore how to deal with these pollutants has become a new research hotspot.In many methods of organic wastewater treatment,the use of adsorbent is more economical and efficient,the study of a highly efficient adsorbent is more promising and meaningful.In this paper,we prepared porous cellulose acetate micro-nano fibrous membranes by changing the spinning conditions,and investigated the influence of spinning conditions on morphology of the fiber by SEM,and then the?-cyclodextrin was grafted to the surface of the cellulose acetate to improve its adsorption performance.The porous regenerated cellulose nanofibrous membrane also was prepared by alkali treatment of cellulose acetate membranes,and the?-cyclodextrin also was grafted to the surface of regenerated cellulose fiber membranes.In this experiment,the grafting reaction was confirmed by IR and NMR,and the best grafting condition was determined by weight method and phenolphthalein probe quantification test.The morphology,specific surface area,hydrophilicity and hydrophobicity as well as thermal stability of nanofibers were investigated systematically.It was found that the fiber prepared in this experiment was more uniform with a diameter of about 1?m and a large specific surface area of more than 200 m~2/g,the specific surface area of regenerated cellulose reached 523 m~2/g.In this study,cellulose acetated,modified cellulose acetate,regenerated cellulose and modified regeneration cellulose were prepared,the adsorption properties to three organic molecules of four kinds of membranes are investigated,they included 2,4-dichlorophenol,4-chlorophenol and methyl orange,and it emphasis on adsorption performance to2,4-dichlorophenol,including the optimal adsorption conditions,isothermal adsorption,adsorption kinetics,adsorption thermodynamics,desorption-regeneration.Results show that:Grafting?-cyclodextrin on the surface of micro-nano fibrous membranes effectively enhances the adsorption properties of the material.Under the optimal conditions,the maximum adsorption capacity to 2,4-dichlorophenol molecules of cellulose acetate,modified cellulose acetate,regenerated cellulose and modified regenerated cellulose were 250 mg/g,251.9 mg/g,44.3 mg/g,49.5 mg/g.The isothermal adsorption processes of four kinds of micro-nano fibrous membranes followed the Freundlich model,which is multi-layer adsorption.The adsorption data of the adsorption equilibrium process were fitted by the quasi-second order kinetic equation,indicating that the adsorption of membranes is dominated by chemisorption.The results of thermodynamic analysis show that the adsorption processes of four fiber membrane are exothermic and spontaneous.In addition,they also have good regeneration performance;the regeneration efficiency is still higher than 75%after recycling 3 times.