Preparation And Properties Of Monolith Based On Hybrid Monomer

Molecularly imprinted polymers are attractive substitutes for natural receptors due to their unique combination of high affinity,specificity and low cost.The rigidity of the imprinted pores is also increased,and the permeability of the molecularly imprinted monolith prepared in combination with the monolith technique can also be improved.In the first part of the thesis,The hybrid monomer APTES-MAA is used as a functional monomer for preparing a molecularly imprinted polymer,which helps to improve the stability between the template and the monomer by its silicon-oxygen skeleton,thereby improving the polymer structure left after the template is removed.In the first part of the paper,the organic-inorganic hybrid imprinted monolith was synthesized with gatifloxacin(GTFX)as template,ethylene glycol dimethacrylate(EDMA)as crosslinker,and APTES-MAA as function monomer in the stainless steel column.Some polymerization factors,including the ratio of the template to APTES-MAA,the ratio of APTES-MAA to EGDMA and porogen ratio on imprinting effect were investigated.The preparation of molecularly imprinted monolith was optimized by investigating the ratio of the template to APTES-MAA,the ratio of APTES-MAA to EDMA and the ratio of isooctane in the binary porogen.The monolith was characterized by scanning electron microscope,infrared spectroscopy and nitrogen adsorption.The results showed that the imprinted monolith prepared by this method had high affinity and selectivity to the template molecule with an imprinted factor of 16.28,which was 6.1 times higher than that of the traditional methacrylic acid-based MIP.The stoichiometric displacement model for retention(SDM-R)was employed to probe into recognition mechanism of template and its analogues on the HMIP.A multimolecular complexes between template and functional monomer with the model of 1:3 was proposed by a study of complex equilibrium.The results suggested that the concept of the hybrid monomer may be a good approach to tailor-made MIP with higher affinity than conventional MIP.The imprinted monolith was used as solid phase extraction(SPE)adsorbent to enrich gatifloxacin in lake water,and the recovery rate was 96.52%,indicating that this monolith can be used for the analysis of complex samples.The results suggested that the concept of the hybrid monomer may be a good approach to tailor-made MIP with higher affinity than conventional MIP.As a kind of green solvent,deep eutectic solvent(DES)was non-toxic to proteins due to good biocompatibility.The hybrid monomer(APTES-MAA)provided a hydrophobic group that interacts hydrophobically with the protein while also improving the mechanical stability of the monolith.In the second part of the paper,the hybrid monolith was synthesized by composite functional monomer of the hybrid monomer(APTES-MAA)and the eutectic solvent(DES)monomer,the ethylene glycol dimethacrylate(EDMA)as the crosslinking agent in in-situ polymerization method.The poly(APTES-MAA-co-DES-co-EDMA)monolith was characterized by field emission scanning electron microscope,specific surface area and pore size analyzer,and thermogravimetric analyzer.Taking bovine serum albumin(BSA)as the research object,the types of functional monomers,the amount of functional monomers,the loading volume,the loading pH,the loading flow rate,the elution flow rate and the elution volume were investigated by single factor experiments.Taking bovine serum albumin(BSA)as the research object,the effects of the type of functional monomer,the amount of functional monomer,sample loading volume,sample loading pH,loading flow rate,the elution flow rate and elution volume on the recovery rate were investigated by single factor experiment.Under the optimum extraction conditions,the recovery reached 96.2%.The solid phase extraction monolith can successfully separate bovine serum albumin and cytochrome C as well good enrichment of the two proteins.The proposed method provided a new idea for the separation and purification of proteins.