Preparation Of EVOH Nanofiber/PS Microsphere Composite Membrane And Study On Separation Performance Of Lysozyme

The rapid development of biopharmaceutical and other industries has increased the demand for the separation of biological macromolecules such as nucleic acids and proteins,and the requirements for separation technology are increasing day by day.Designing and developing efficient bioseparation materials has become a key factor in the development of the modern biopharmaceutical industry.Traditional bioseparation technologies relying on chromatographic packing have problems such as low separation rate,high cost,and short life of separation materials.Nanofibers have the characteristics of high porosity,easy regulation of pore size and easy functionalization,and have high advantages in biological separation.In this paper,nanofibers and polystyrene microspheres(PS)were combined to prepare nanofiber/PS microsphere composite membrane materials.The preparation of cationexchange composite chromatographic membrane material with adjustable function and function was carried out,and its adsorption and elution performance on lysozyme was analyzed.The research content of this paper is mainly divided into the following three parts:(1)Research on nanofiber-PS microsphere composite membrane material and microfiltration performance.Ethylene vinyl alcohol copolymer nanofibers with different diameters were prepared by melt blending method,and nanofibrous membranes(EVOH)with different pore sizes were prepared.Polystyrene microspheres(PS)with different particle sizes were prepared by emulsion polymerization.The PS microspheres were added to the nanofiber suspension to prepare the nanofiber/PS microsphere composite membrane.Compared with the 100 nm pure nanofiber membrane,the average pore size of the composite membrane after adding microspheres is reduced to 60nm;compared with the 300 nm pure nanofiber membrane,the average pore size of the composite membrane after adding microspheres is reduced to120nm;compared with 700 nm Compared with the pure nanofiber membrane,the average pore size of the composite membrane after adding microspheres is reduced to 500nm;from the comprehensive pore size distribution and pure water flux data,compared with the pure nanofiber membrane,the average pore size of the composite membrane is reduced to 500 nm.Under the same conditions,the pure water flux can still maintain the original level and has excellent flux stability.Compared with similar products,it is undoubtedly possible to filter finer particles after the pore size becomes smaller.The filtration capacity of the membrane within the same time period Larger,more improved filtration efficiency.(2)Nanofiber-SPS microspheres cation chromatography membrane and lysozyme separation performance.Polystyrene(PS)microspheres were prepared by emulsion polymerization,and sulfonated polystyrene microspheres(SPS)were successfully prepared by ultrasonically dispersing them in concentrated sulfuric acid(H2SO4).According to the above preferred formulation,the prepared SPS microspheres and the nanofiber suspension are uniformly mixed to prepare a film.The results show that the nanofiber-SPS microsphere cation chromatography membrane has the characteristics of high flux,high flux stability and small pore size.And it has a good lysozyme adsorption effect,the adsorption capacity is230mg/g,and the adsorption capacity can still be maintained for more than 5 times of elution,showing good reusability;and the difficulty that the traditional particles cannot be collected after adsorption can be solved.(3)Study on the separation performance of nanofiber cation chromatography membrane and lysozyme.The nanofiber suspension was sprayed on PP substrate to prepare EVOH nanofiber membrane(EVOH),which was then activated by sodium hydroxide solution,reacted with cyanuric chloride,and grafted with acid fuchsin to obtain nanofiber cation chromatography membrane.The adsorption effect of nanofiber membranes with different diameters on lysozyme was explored,and the three methods in this chapter were compared through five dimensions: pure water flux,flux decline rate,average pore size,the amount of the maximum adsorbed solution,and the static adsorption amount of lysozyme.seed membrane.The results show that the average pore size of the prepared nanofiber cation chromatography membrane is larger than that of the nanofiber membrane,which may be because some nanofibers are dissolved during the reaction,and the flux performance is improved,but the overall performance trend remains the same as the above.Consistent.It has a good adsorption effect on lysozyme,the adsorption capacity can reach 280mg/g,has a good elution capacity,and shows good reusability.