Preparation And Application Of Supermacroporous Cryogel Microspheres

Cryogel is a new type of biological separation material with large pore structure of tens of micrometers.The cryogel as separation medium can be used for extracting and separating the target from raw materials with high speed,especially to achieve efficient and rapid separation of macromolecules because of the large pores.Compared with the monolithic column,the preparation and application of microspheres are less affected by the reaction vessel.At present,most of the cryogel microspheres are prepared under the zero degree,where ice crystals were used as porogen templates.So most cryogel microspheres were hydrophilic with low mechanical strength,which were not used for rapid separation and analysis under pressurized conditions.However,there are few reports on macroporous hydrophobic cryogel microspheres because of the limit of monomer solubility.Lauryl alcohol is of extensive solubility for most of nonpolar monomers and its melting point is 24.5 ?.In this work,we used lauryl alcohol as solvent and porogens and applied a traditional suspension polymerization technique at below the melting point of lauryl alcohols.This paper designed a series of experiments for preparing cryogel microspheres,the specific contents are as follows:1: The cryogel microspheres were prepared by a combination of traditional suspension polymerization and cryo-polymerization with lauryl alcohol as solvent and porogen,glycidyl methacrylate(GMA)as functional monomer,trimethylolpropane trimethacrylate(TRIM)or ethyleneglycol dimethacrylate(EGDMA)as crosslinker,polyvinyl alcohol(PVA)as stabilizer and sodium lauryl sulfate(SLS)as co-stabilizer,benzoyl peroxide(BPO)and N,N-dimethyl aniline(DMA)as redox initiator system.In this article,the effects of the preparation conditions of stabilizer,polymerization temperature,crosslinker,porogen and initiator on the macroporous cryogel microspheres were investigated by scanning electronic microscope(SEM)and laser particle size analyzer(DLS).Experimental results show that the selection of stabilizers and polymerization temperature are main influence factors for the suspension droplets,The morphology and the pore structure of the cryogel microspheres were mainly related to the relationship between the rate of solvent crystallization and the polymerization rate.2: Sulfamethoxazole(SMZ)grafted to the surface of the cryogel microsphere by ring-opening reaction of SMZ with epoxy groups.Then,adsorption experiments were performed for two different proteins,and the results showed that the functional microsphere had specific adsorption for trypsin,the adsorption of trypsin on grafted cryogel microspheres is about 1.75-fold compared to that of before the graft.3: Preparation of polyethylene glycol diacrylate(PEGDA)cryogels with supermacroporous by introducing polydivinylbenzene(PDVB)microspheres were investigated preliminarily in this paper.The cryogel monolithic column were prepared by crosslinking the PDVB with PEGDA under low temperature conditions with dimethyl sulfoxide(DMSO)as porogen and solvent,benzoyl peroxide(BPO)and N,N-dimethyl aniline(DMA)as redox initiator system.The characterization and analysis were carried out by scanning electron microscope,infrared spectrum and contact angle.The experimental results show that the pore diameter of the cryogel is 10~50 ?m and related to the amount of DMSO.Pore size of cryogels increases with the increasing of the DMSO content.In addition,the forming cryogels display hydrophilic and hydrophobic properties by contact angle method.