Ion-Exchange Monolithic Column Prepared By High Internal Phase Emulsion And Its Application In Protein Separation

Over the past few decades,macroporous polymer materials with interconnected structures have played a role in many different fields.High internal phase emulsions（HIPE）are increasingly used in the preparation of polymeric porous materials.This approach typically produces honeycomb monoliths with interconnected pores,called PolyHIPE.These materials have been widely used in different aspects,including separators for batteries,electrochemical sensors,tissue engineering,supported catalysis,water purification and separation science.Most of the macroporous polymeric materials used in separation science are composed of hydrophobic polymers,which limits their application in the separation of biological macromolecules,and the preparation of most monolithic columns is still limited to capillary analytical columns.Based on the second,in this paper,a monolithic column was prepared in situ in a modified glass tube with a large inner diameter by the high internal phase emulsion method,and then modified.The modification conditions were mild,and in the ion exchange mode,The standard protein was basically separated under the no pressure conditions.The separation process was environmentally friendly,efficient and safe.The chromatographic and adsorption conditions were optimized,and satisfactory results were obtained.（1）In order to avoid the column wall effect and improve the biocompatibility of the monolithic column,a Poly（HEMA-co-AA-co-MBA）hydrogel was prepared in a silane-modified glass column via an oil-in-water high internal phase emulsion template method.The modified glass column tube is tightly combined with the hydrogel matrix,and the macroporous hydrogel（H3NDP）prepared with an internal ratio of 80%has both through-through macropores and good mechanical properties（compressive strength:0.69MPa）.A polydopamine/polyethyleneimine（PDA/PEI）composite dielectric layer was constructed on the surface of the hydrogel to increase the amino group content and serve as a support material to improve the mechanical properties of the macroporous hydrogel.The permeability of the modified H3NDP was 5.83×10^-13 m²,and the enhanced permeability benefited from the through macropores.The quaternized monolithic column can separate five proteins,and the surface modification technology using PDA and PEI as media provides a new idea for enhancing the adsorption and separation performance of the monolithic column.（2）PolyHIPE with submicron skeleton and through macropores was obtained in the modified glass column by the high internal phase emulsion template method.The glass column tube is closely attached to the GMA-based polymer,and the mesh-like porous structure formed by the fine skeleton increases the specific surface area of PolyHIPE.The specific surface area measured by nitrogen adsorption method is 16.01 m²·g^-1.Using epoxy groups as reaction sites,sulfonic acid groups were introduced on the surface of PolyHIPE to prepare cation exchange monolithic columns.The results show that the prepared cation exchange monolithic column has the ability to adsorb and separate proteins.The dynamic adsorption capacity of the prepared cation exchange monolithic column for protein was0.13 mg/mm²,and it had good reusability.（3）PolyHIPE with submicron skeleton and through macropores was obtained in the modified glass column by the high internal phase emulsion template method.The glass column tube is tightly attached to the GMA-based polymer.Anion exchange monolithic columns were prepared by directly introducing quaternary ammonium groups on the surface of PolyHIPE with epoxy groups as reaction sites with triethylamine hydrochloride and epoxy group ring-opening.The results show that the prepared anion exchange monolithic column has the ability to adsorb and separate proteins.The dynamic adsorption capacity for BSA was 0.143 mg/mm²,but it did not reach the good adsorption and separation performance of the quaternized monolithic column prepared in Chapter 2 for protein,which demonstrated the superiority of the surface modification technique with PDA and PEI as mediators in Chapter 2.