The carboxyethyl chitosan(CEC)was synthesized by chitosan as materails with acrylic acid by Michael reaction.The factors such as mass ratio,pH value,time and temperature were investigated and the structure of the CEC ...The carboxyethyl chitosan(CEC)was synthesized by chitosan as materails with acrylic acid by Michael reaction.The factors such as mass ratio,pH value,time and temperature were investigated and the structure of the CEC was characterized by FT-IR,1H NMR.The results show:the mass ratio is 1:4,the best pH value is 6,the time is 5h and the optimum temperature is 90℃,the substitution degree of CEC is 0.75.The reaction proceeded in a short time compared with literature,The carboxyethylation mainly occurred on NH2.展开更多
Chitosan and chitosan membranes with Pb(Ⅱ) ion as template were studied. The adsorption isotherms were correlated by dc/dt=-kcn at the temperature of 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃. By means of linear correlation,...Chitosan and chitosan membranes with Pb(Ⅱ) ion as template were studied. The adsorption isotherms were correlated by dc/dt=-kcn at the temperature of 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃. By means of linear correlation, the shapes of the isotherm curves were similar to the kinetic function of 2/C=-kt and the apparent activation energy for with chitosan(123.8 kJ·moL-1) was larger than that of membrane with Pb(Ⅱ) ion(92.3 kJ·moL-1). The chitosan membrane with Pb(Ⅱ) ion template was better "memory" function. The adsorption mechanism of chitosan with Pb(Ⅱ) was studied by IR and XPS. The results indicated that the nitrogen in-NH2 and the oxygen in C3-OH of chitosan were coordination atoms.展开更多
文摘The carboxyethyl chitosan(CEC)was synthesized by chitosan as materails with acrylic acid by Michael reaction.The factors such as mass ratio,pH value,time and temperature were investigated and the structure of the CEC was characterized by FT-IR,1H NMR.The results show:the mass ratio is 1:4,the best pH value is 6,the time is 5h and the optimum temperature is 90℃,the substitution degree of CEC is 0.75.The reaction proceeded in a short time compared with literature,The carboxyethylation mainly occurred on NH2.
文摘Chitosan and chitosan membranes with Pb(Ⅱ) ion as template were studied. The adsorption isotherms were correlated by dc/dt=-kcn at the temperature of 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃. By means of linear correlation, the shapes of the isotherm curves were similar to the kinetic function of 2/C=-kt and the apparent activation energy for with chitosan(123.8 kJ·moL-1) was larger than that of membrane with Pb(Ⅱ) ion(92.3 kJ·moL-1). The chitosan membrane with Pb(Ⅱ) ion template was better "memory" function. The adsorption mechanism of chitosan with Pb(Ⅱ) was studied by IR and XPS. The results indicated that the nitrogen in-NH2 and the oxygen in C3-OH of chitosan were coordination atoms.