Molecularly Imprinted Polymers And Their Application In Selective Separation Of Active Components From Plants And Removal Of Organic Sulfide In Fuel Oils

The purpose of investigation of molecularly imprinted technology (MIT) iscontinually developing its application area, the essence of which is expanding types ofapplicative template. It is always a research focus of investigators. As the physical,chemical properties and molecular structure of templates are different, the methods ofimprinting these templates are different. Athough the techonogy of imprinting smallmolecule is very mature, imprinting molecules having special structure or propertiesis still difficult.In this paper, taking account of the strong polarities of some active components ofplants, which have the feature of poor solubility in most organic solvent and difficultformation of non covalent forces with functional monomers in most organic solvent,we had prepared relevant molecularly imprinted polymers (MIPs); consideringcomplex components of extracts of plants and difficult selective sparation of targetmolecule with traditional methods, we had developed effective method for separationof complex components in extracts of plants combinating with solid-phase extraction(SPE); thinking about that removing of intractable sulfide in feul oils is difficult withtraditional methods and less functional monomers using in the past MIT for removalof sulfide and its volatility, we had developed a environmental friendly MIPs forremoval of sulfide; in view of ineffective MIPs for removal of sulfide using in thepast, we had synthesized MIPs having the features of anti-interference and goodcompatibility in oils. The details are summarized as follows:1. The main functional monomers using in the synthsis of MIPs for removal ofsulfide in feul oils is vinyl pyridine, which is not environmental. In view of ionicliquid which is non-volatile and devisable, we had synthesized1-acrylate-3-vinylimidazolium bromide (PVMBR), which is soluble in weak polarsolvent. The preparation process is simple. The productivity of product is up to81.6%. The chemical structure of PVMBR was confirmed by1H NMR and MSanalysis.2. We describe a molecularly imprinted polymer (MIPs) for the solid-phaseextraction of the skin protectant allantoin. The MIP was deposited on the surface ofmonodisperse silica microspheres possessing acroyl groups on the surface (MH-SiO2).The resulting MIP microspheres (MH-SiO2@MIP) showed a3.4-fold higheradsorption capacity and a1.9-fold better selectivity for allantoin than the respective non-imprinted polymer (MH-SiO2@NIP). The monolayer adsorption capacities of theMH-SiO2@MIP and the MH-SiO2@NIP were calculated with the help of theLangmuir model and found to be6.8and1.9mg g1, respectively. Adsorption kineticsfit a pseudo-second order rate mechanism, with an initial adsorption rate of1.44forthe MH-SiO2@MIP, and of0.07mg g1min1for the MH-SiO2@NIP. The materialcan be regenerated, and its adsorption capacity for allantoin remains stable for at leastfive regeneration cycles. It was successfully used as a sorbent for the selectivesolid-phase extraction of allantoin from Rhizoma dioscoreae.3. We had prepared novel dibenzothiophene molecularly imprinted polymers(NDMIPs, NDMIP and NDNIP) using PVMBR as functional monomer, which issoluble in mixed solvent methanol/toluene. NDMIPs were confirmed by IR analysisand SEM. The performance of NDMIPs was investigated by isothermal, kinetics andselectivity. As show in results, adsorption behavior accords with Freundlich modeland the kfis0.2946and0.0713, belong to NDMIP and NDNIP, respectively. The h0is1.62g mg-1min-1and0.49g mg-1min-1, belong to NDMIP and NDNIP, respectively.The is2.18and1.86for NDMIP, towards to benzothiophene and4,6-dimethyldibenzothiophene, respectively. The times of reuse were more than5.4. We had prepared MIPs with hydrophobic polymer brushes on the surface usingsurface molecularly imprinted technology and Reversible Addition-Fragmentationchain Transfer (RAFT) polymerization. The MIPs were confirmed by IR analysis andSEM. The performance of MIPs was investigated. It was showed in the results thatanti-interference, compatibility in oils and regenerability was well.