Study On Preparation Of Hierarchically Porous Membrane And Adsorption Performance Of Isoflavone In Radix Puerariae Lobatae

Radix Puerariae Lobatae is a very common traditional Chinese medicine which contains many isoflavones as medicinal composition,such as genistein.It’s difficult to separate and purify the isoflavones because of the similarities of isoflavone structure.Molecular imprinted membrane(MIM)combines the advantages of molecular imprinting technology and membrane separation technology,has a grate potential application in the field of separation and purification.Due to its unique physical and chemical properties,graphene materials can be used as a kind of new adsorption material in the field of separation and purification.In this work,MIM which can specifically recognize genistein and reduced graphene oxide composite membrane(RGOCM)were prepared,the properties of the two materials and the practical application in Radix Puerariae Lobatae were studied.1.Genistein-precursor(GENP)was prepared by genistein and acryloyl chloride(AC),choosing dimethyl sulfoxide(DMSO)as solvent,acrylamide(AM)as the non-covalent functional monomer,ethylene glycol dimethyl acrylate(EDGMA)as crosslinking agent,polyethylene glycol(PEG)2000 as porogen,ammonium persulfate(APS)as initiator,N,N,N,N-tetramethyl ethylenediamine(TEMED)as catalyst,cryogenic hierarchically imprinted porous membrane(C-MIM)was prepared by cryopolymerization.Influence of the type and addtion of non-covalent functional monomer,the dosage of the cross-linking agent and PEG 2000 on absorption performance of membrane were investigated.The study found that the sorption of C-MIM was fitted well with the first order kinetics and Langmuir isotherm,was mainly monolayer adsorption process and easy to occur.The selective test,static penetration pool experiment and dynamic filtration experiment all showed that C-MIM has a certain selectivity of genistein.C-MIM was applied to the actual samples,the adsorption rate of genistein in the extraction of Radix Puerariae Lobatae was 70.6%.2.The prepared graphene oxide(GO)was dispersed into aqueous solution which contained dispersive polystyrene(PS)microspheres,the mixture was filtered through a mixed cellulose ester membrane by vacuum suction,then the graphene oxide membrane(GOM)containing PS microspheres was prepared.The GOCM was prepared by immersing GOM in the casting solution with(3-aminopropyl)triethoxy-silan(APTS).The GOCM was reduced to RGOCM by heat treatment with ethanol / ammonia and ethanol / hydrochloric acid,then the adsorption performance of RGOCM for several isoflavones in Radix Puerariae Lobatae was studied.The effects of the ammount of APTS and F-127(mesoporous template),and the particle size of PS microspheres(macroporous template)on the adsorption capacity of RGOCM were investigated.It was found that the sorption of RGOCM was more consistent with the second order kinetic equation and Freundlich isotherm model.The adsorption process was easy to adsorb and the adsorption was spontaneous and endothermic.In the experiment,the adsorption selectivity of RGOCM was also investigated.The adsorption selectivity of RGOCM and the eluent was also investigated.In the end,RGOCM was applied to the extraction of Radix Puerariae Lobatae,and the enrichment of daidzein and genistein was achieved.