Thermo-sensitive hydrogels based on N-isopropylacrylamide (NIPAM) containing L-amino acid groups were designed and synthesized for chiral resolution.L-tryptophane was used as chiral pool

after esterifization and condensation reactions with acryloyl chloride and the chiral monomer AAc-L-Trp was obtained

and the structure was characterized by IR and 1H-NMR.Then the subsequent copolymerization was carried on between AAc-L-Trp and NIPAM with N

N'-methylenebisacrylamide (MBAA) as linkage agent in the presence of azobisisobutyronitrile (AIBN) in ethanol with different weight ratios.The resulted poly-(NIPAM-co-AAc-L-Trp) hydrogels were identified by IR.The swelling behaviors

deswelling and reswelling kinetics of the chiral hydrogels have been studied

and the results showed that all the poly(NIPAM-co-AAc-L-Trp) hydrogels exhibited evident temperature-sensitivity.Due to the hydrophobicity of chiral monomer incorporated into the structure of the chiral gels

the thermo-sensitivity of the chiral gels is lower than that of PNIPAM gel

and the lower critical solution temperature (LCST) decreased with increasing of the contents of chiral monomer.The chiral adsorption and separation performance were also investigated using D/L-phenylalanine (D/L-Phe) as a model.The results indicated that compared with PNIPAM gel

the chiral gels performed higher adsorption rate and larger adsorption quantities for D-Phe enantiomers.Increasing the contents of chiral monomer or the temperature will improve the efficiency of resolution of DL-Phe.