Temperature-sensitive molecularly imprinted microgels(MIGs)exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate(PAD-His)as the functional macromonomer an...Temperature-sensitive molecularly imprinted microgels(MIGs)exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate(PAD-His)as the functional macromonomer and p-nitrophenyl phosphate(NPP)as the stable transition state analogue(TSA)as well as Co2+as the coordination center.The catalytic activity of MIGs was greatly influenced by the amount of the template,and could be modulated by temperature.The hydrolysis kinetics of p-nitrophenyl acetate(NPA)in the presence of MIGs could be described by the Michaelis-Menten equation.The MichaelisMenten constant and maximum velocity were found to be 2.2×105mol/L and 2.04×10 -8mol/h,respectively.In addition,the MIGs were found to have a high catalytic selectivity to NPA.展开更多
The alkaline hydrolysis of 4-Nitrophenyl acetate was studied at 30℃±0.1℃ in the micellar solutions of three surfactants(Brij35,CTAB and SDS).Based on the psedrophase model of micellar catalysis of Menger and Po...The alkaline hydrolysis of 4-Nitrophenyl acetate was studied at 30℃±0.1℃ in the micellar solutions of three surfactants(Brij35,CTAB and SDS).Based on the psedrophase model of micellar catalysis of Menger and Portnoy,the kinetic equations of micellar catalysis were derived.The results indicated that CTAB micellar system effectively catalyzed the hydrolysis of carboxylic ester,compared with Brij35 and SDS micallar systems under the same reaction conditions.Kψ and km of PNPA hydrolysis increase with the rising in the concentration of NaOH reaction system.Furthermore,the chemical kinetic parameters k1m and k2m in the micellar psedrophase and association constant reactant with micellar KS were calculated with the kinetic equations of micellar catalysis.展开更多
基金supported by the National Natural Science Foundation of China(21074152,20874116,20676155 and J0730420)the Natural Science Foundation of Guangdong Province in China(8151027501000004 and 9151027501000105)the Doctoral Research Program of Ministry of Education Ministry of China(20090171110023)
文摘Temperature-sensitive molecularly imprinted microgels(MIGs)exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate(PAD-His)as the functional macromonomer and p-nitrophenyl phosphate(NPP)as the stable transition state analogue(TSA)as well as Co2+as the coordination center.The catalytic activity of MIGs was greatly influenced by the amount of the template,and could be modulated by temperature.The hydrolysis kinetics of p-nitrophenyl acetate(NPA)in the presence of MIGs could be described by the Michaelis-Menten equation.The MichaelisMenten constant and maximum velocity were found to be 2.2×105mol/L and 2.04×10 -8mol/h,respectively.In addition,the MIGs were found to have a high catalytic selectivity to NPA.
文摘The alkaline hydrolysis of 4-Nitrophenyl acetate was studied at 30℃±0.1℃ in the micellar solutions of three surfactants(Brij35,CTAB and SDS).Based on the psedrophase model of micellar catalysis of Menger and Portnoy,the kinetic equations of micellar catalysis were derived.The results indicated that CTAB micellar system effectively catalyzed the hydrolysis of carboxylic ester,compared with Brij35 and SDS micallar systems under the same reaction conditions.Kψ and km of PNPA hydrolysis increase with the rising in the concentration of NaOH reaction system.Furthermore,the chemical kinetic parameters k1m and k2m in the micellar psedrophase and association constant reactant with micellar KS were calculated with the kinetic equations of micellar catalysis.
