The Expense Of Silica Gel Synthesis Of Molecular Imprinted Polymers In The Resolution Of Dl-phenylalanine In Applied Research,

In this thesis, progress on synthetic method or technology of molecular imprinting polymers (MIPs) was reviewed. As a kind of artificial molecular recognition materials, imprinted polymers, with many applications including in separation or synthesis of chiral compound, catalysis with high selectivity, mimic sensors and so on are summarized in detail. Production methods cosmically of L-2-amino-3-phenylpropanoic acid (L-Phe) are introduced briefly. Consequently, the profound impact with utilizing molecular imprinting technology on separating racemate of Phe is pointed out.Three methods are used to prepare molecular imprinting polymers, which include conventional bulk technique, emulsion polymerization and polymerization with silica-gel as sacrificial materials. In the polymerization procedure, L-Phe is selected as a template molecule, a -methacrylic acid and p-vinyl pyridine as functional monomers, glycol dimethacrylate and 1,4-divinylbenzene as crosslinkers, chloroform and dimethyl sulfoxide as solvents with proper proportion. Specific surface area and pore volume of MIPs and particle size distribution were examined through B.E.T. experiment and laser granularity distribution apparatus respectively in describing polymers' shape. Adsorption isotherms, adsorption dynamics and static adsorption ability of MIPs for L-Phe were measured by Ultraviolet (UV) absorption measure technology. Dynamic adsorption ability of MIPs was examined by combination utilizing of UV and optical activity analysis.Factors which impact on MIPs shape and adsorption ability are pointed out, especially, some interrelated prominent factors, stabilization property of complex, reactive time, temperature, species and usage of initiator and crosslinker, treatment after polymerization and so on. Three important concepts namely inner solvent, outer solvent and solid phase solvent are firstly designated which will be convenient to design and prepare polymers in the future. Saturation adsorption quantity and dissociated constant of polymers for L-Phe are calculated by Scatchard analysis. Specific surface area and pore volume, which are two key factors on MIPs adsorption ability, are indicated. The results of adsorption isotherms research have proven thatthe adsorption model comparability between MIPs and Langmuir for substrate. The results of adsorption dynamics researches qualitatively have shown the adsorption rate of MIPs for template molecule. Quantitative analysis principles, which MIPs are used as chromatographic chiral stationary phase in application of enantiomer separation, are provided by analyzing of column chromatography and calculating dynamic separating factor.The method based on silica-gel as sacrificial materials for preparing L-Phe MIPs highlights the remarkable advantages: large saturation adsorption amount, high static or dynamic separating factor and equilibrium velocity that provided scientific principles for producting cosmically D- or L- Phe from separating racemate.