L - Phenylalanine Molecularly Imprinted Polymer (film) Synthesis And Performance Research

The chiral resolution of amino acids isomers is importance in boh theory and reality, and of great difficulty. Applying molecular imprinting technology (MIT) and molecularly imprinted membrane (MIM) to the chiral resolution of amino acids isomers, become one of the hot spot in the recent research. L-Phennylalanine (L-Phen) is one of essential amino acids, and is a important intermediate in both medicine and edible chemical. So, establishing a rapid and efficient chiral resolution method for phenylalanine racemates is a important.On the basis of refering extensive relevant literatures of chiral resolution methods of amino acids isomers, this thesis summarized and discussed the various features and applications of they. On this basis, using the pretermined selectivity of MIT synthesized a series of molecular imprinted polymers (MIPs) and MIMs, which used L-Phennylalanine as the resarech object and optimized by the way of single factor optimization. Their recognition and selectivity properties were studied. The specific research works were carried as follows:1. Using synthesized three new chiral functional monomer (S)-N-(1-phenylethyl) acrylamide [(S)-PEA],(S)-N-(1-phnylethyl)methacrylamide [(S)-PEMA],(L)-allylpyrrolidine-2-carboxylate [(L)-APLC] and single factor optimization, optimized the conditions of the L-Phen imprintng polymers polymerization, including polymerization methods, type of porogen solvents, the amount of crosslinker and three new chiral functional monomer. The results showed that the L-Phen imprinted polymers synthesized by sacrifice silica gel method preparing with (S)-PEA as functional monomer, Water/Methanol (1:1,v/v) as porogen solvent under the mole ratio of L-Phen,(S)-PEA and crosslinker as1:4:20, which had the optimum absorption performance in all L-MIPs. The optimized L-MIP showed the good imprinting efficiency (QMIP/QNIP=2.76) and high adsorption capacity (Q=43.82mg/g). Then establishing a performance liquid chromatography (HPLC) method for determination and separation of L-Phen to study the selective recognition of the opti-mum L-MIP, the results showed the selective factor of the optimum L-MIP towards L-Phen on phenylalanine racemates separation were caculated as1.51. In addition, scatchard analysis and adsorption kinetics was used to analyze adsorption characteristics of the optimum the polymer; morphologies of the optimum L-MIP were characterized with Fourier transform infrared (FT-IR), surface area analysis (BET) and scanning electron microscope (SEM), respectively.2. In order to verify the well chiral selectivity towards L-Phen of the optimum L-MIP and (S)-PEA, the optimized D-MIP was synthesized by bulk polymerization, using D-Phennylalanine (D-Phen) as template molecular,(S)-PEA as functional monomer, Water/tetrahydrofuran (1:l,v/v) as porogen solvent under the mole ratio of D-Phen,(S)-PEA and crosslinker as1:4:30. Then the selective factor of the opyimum D-MIP towards L-Phenn on phenylalanine racemates separation was1.34, which determining by the HPLC merhod. The result showed the well chiral separation of the optimum L-MIP and (S)-PEA.3. A series of L-Phen MIMs were prepared by single optimization considering supporting membrane, type of porogen solvents, the amount of crosslinker, soaking-time and three new chiral functional monomer. The optimized conditions displayed that the L-Phen imprinted composite membrane synthesized with Nylon-6membrane as supporting membrane,(S)-PEMA as functional monomer, Water/Methanol (1:l,v/v) as porogen solvent, soaking3minutes, under the mole ratio of L-Phen,(S)-PEA and crosslinker as1:4:30, showed the good imprinting fator as1.41. Moreover the optimum MIM was furthermore studyed its selectivity by osmosis adsorption experment, and was analyzed its membrane structure and surface features by FT-IR, SEM and BET analysis.