Study On The Structure Regulation And Application Of Hydrophilic Gigaporous Polystyrene Microspheres

With the rapid development of modern biotechnology,the application of protein becomes more and more extensive.However,most biomacromolecules exist in the form of mixture and need to be purified prior to using in the fields of life sciences and medicines.Liquid chromatography is the most effective tools for proteins separation.Recently,there are increasing interests in developing bioseparation media with high column efficiency,high column capacity,high-speed velocity and low activity loss.Considering the current situation of bioseparation media,we developed a novel method to prepare hydrophilic gigaporous polystyrene microspheres(HGPS).Amphiphilic diblock glycopolymers(ADG)were firstly synthesized via atom transfer radical polymerization(ATRP)method.Taking ADG as oil phase surfactant,a bottom-up approach based on surfactant reverse micelles swelling method was proposed to prepare HGPS.After further derivatization,the high-speed separation performance of this gigaporous medium was preliminary studied.The dissertation was divided into three parts.In the first part,we successfully synthesized ADG using diacetone-D-glucose as raw material by four-step reactions.This part mainly explicited the principle that reverse micelles formed by ADG in the oil phase could absorb water spontaneously.The water absorption process of ADG reverse micelles was characterized by confocal laser scanning microscopy(CLSM)observation,conductivity and viscosity measurements.The emulsion structure was dominately affected by the property of ADG,and it was found that the water absorption capacity of the reverse micelles increased with the HLB value and concentration of ADG in the oil phase.The pseudoternary phase diagram of W/S/O system was successfully constructed by the clear judgment of the emulsion state,and it was clarified that bicontinuous phase could stably exist,which is the necessary condition to form connected pore structure.In the second part,the HGPS microspheres were prepared by surfactant reverse micelles swelling method.The results indicate that ADG with HLB value in the range of 3.6-4.5 could form ideal gigapores in the HGPS microspheres.The pore size of HGPS microspheres will increase with the molecular weight and concentration of ADG,which is in good accordance with the rule of water adsorption capacity of reverse micelles.In addition,the specific surface area of microspheres could be adjusted by addition of small molecular porogen.The HGPS microspheres with meso-and giga-pores can be successfully prepared via coordinated regulation of the HLB value,molecular weight and adding amount of ADG,as well as the addition of porogenic agent-toluene.Combined with the structure of W/S/O bicontinuous emulsion,the formation mechanism of gigaporous structure of HGPS microspheres was verified.Protein adsorption and water content measuring experiments indicate the HGPS microspheres have good hydrophilicity and biocompatibility,resulting from the successful integration of ADG in the microspheres.Hydrodynamic experiment confirmed the good mechanical strength and permeability of microspheres,resulting from PS skeleton and the existence of through pores in the particles.In the third part,HGPS microspheres were further coupled with DEAE groups to prepare DEAE-HGPS anion exchange matrix.Taking bovin serum albumin(BSA)as probe protein to evaluate the column efficiency of DEAE-HGPS column,we found there is no obvious relevance between height equivalent to a theoretical plate(HETP)and flow velocity.The HETP of DEAE-HGPS column is only 2.7 mm at the flow velocity of 3612 cm/h,indicating the existence of convective mass transfer in the particles.Protein separation experiment showed that the protein mixture can be separated completely at the flow velocity of 1806 cm/h within 5 minutes by using a DEAE-HGPS column,which is very promising in high-speed protein chromatography.