In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemic...In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemical methods and IR spectrometry. The results showed that the loading of Pr (III) ions was strongly dependent on pH of the medium and the optimal adsorption condition is in HAc-NaAc medium with pH value of 3.0. Adsorption kinetics of Pr (III) ions onto D72 resin could be best described by pseudo-second-order model. The maximum adsorption capacity of D72 for Pr (Ⅲ) was evaluated to be 294 mg·g 1 for the Langmuir model at 298K. The apparent activation energy, E a , was 14.71 kJ·mol 1 . The calculated data of thermodynamic parameters, ΔSΘ value of 100 J·mol 1 ·K 1 and ΔHΘ value of 8.89 kJ·mol 1 , indicate the endothermic nature of the adsorption process, while a decrease of ΔGΘ with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Pr (Ⅲ) can be eluted by using 1.00 mol·L 1 HCl-0.50 mol·L 1 NaCl solution and the D72 resin can be regenerated and reused. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The characterization before and after adsorption of Pr (Ⅲ) ions on D72 resin was conformed by IR.展开更多
以非诺贝特酸和异丙醇为原料,大孔强酸性阳离子交换树脂(D72)为催化剂合成非诺贝特,对影响反应的因素进行研究。实验表明:在非诺贝特酸用量0.2mol,n(异丙醇)∶n(非诺贝特酸)=4.5,甲苯100mL,催化剂D72树脂用量10g,反应2.5h的条件下,产物...以非诺贝特酸和异丙醇为原料,大孔强酸性阳离子交换树脂(D72)为催化剂合成非诺贝特,对影响反应的因素进行研究。实验表明:在非诺贝特酸用量0.2mol,n(异丙醇)∶n(非诺贝特酸)=4.5,甲苯100mL,催化剂D72树脂用量10g,反应2.5h的条件下,产物的收率可达86.7%,含量达99.9%(HPLC),催化剂重复使用5次,收率未见明显降低,其结构经IR、1 H NMR、13 C NMR确证。展开更多
The adsorption isotherms of caffeine from aqueous solution onto three hydrogen donating adsorbents - hydroxypolystyrene. polystyrene-azo-pyrogallol, and D72 resin-were measured. The adsorption enthalpies calculated fr...The adsorption isotherms of caffeine from aqueous solution onto three hydrogen donating adsorbents - hydroxypolystyrene. polystyrene-azo-pyrogallol, and D72 resin-were measured. The adsorption enthalpies calculated from the isotherms according to the Clausius-Clapeyron equation were-24~ -36kJ/mol, -32~ -37kJ/mol. and -19~ -24kJ/mol respectively These values implied that the absorption processes were based on hydrogen bonding. Furthermore, the mechanism of the adsorption of caffeine onto D72 resin was studied by IR spectra and the small molecular model experiments. and the results showed that the adsorption of caffeine onto hydrogen donating adsorbents was based on hydrogen bonding.展开更多
基金Supported by the National Key Technologies Research and Development Program of China (2008BAD94B09)the Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Zhejiang Sci-Tech University)+1 种基金the Ministry of Education(2011007)the Zhejiang Provincial Scientific Research Project (Y201223624)
文摘In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemical methods and IR spectrometry. The results showed that the loading of Pr (III) ions was strongly dependent on pH of the medium and the optimal adsorption condition is in HAc-NaAc medium with pH value of 3.0. Adsorption kinetics of Pr (III) ions onto D72 resin could be best described by pseudo-second-order model. The maximum adsorption capacity of D72 for Pr (Ⅲ) was evaluated to be 294 mg·g 1 for the Langmuir model at 298K. The apparent activation energy, E a , was 14.71 kJ·mol 1 . The calculated data of thermodynamic parameters, ΔSΘ value of 100 J·mol 1 ·K 1 and ΔHΘ value of 8.89 kJ·mol 1 , indicate the endothermic nature of the adsorption process, while a decrease of ΔGΘ with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Pr (Ⅲ) can be eluted by using 1.00 mol·L 1 HCl-0.50 mol·L 1 NaCl solution and the D72 resin can be regenerated and reused. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The characterization before and after adsorption of Pr (Ⅲ) ions on D72 resin was conformed by IR.
文摘以非诺贝特酸和异丙醇为原料,大孔强酸性阳离子交换树脂(D72)为催化剂合成非诺贝特,对影响反应的因素进行研究。实验表明:在非诺贝特酸用量0.2mol,n(异丙醇)∶n(非诺贝特酸)=4.5,甲苯100mL,催化剂D72树脂用量10g,反应2.5h的条件下,产物的收率可达86.7%,含量达99.9%(HPLC),催化剂重复使用5次,收率未见明显降低,其结构经IR、1 H NMR、13 C NMR确证。
基金Supported by the National Natural Science Fsundation of China !(Grant No. 29574164)
文摘The adsorption isotherms of caffeine from aqueous solution onto three hydrogen donating adsorbents - hydroxypolystyrene. polystyrene-azo-pyrogallol, and D72 resin-were measured. The adsorption enthalpies calculated from the isotherms according to the Clausius-Clapeyron equation were-24~ -36kJ/mol, -32~ -37kJ/mol. and -19~ -24kJ/mol respectively These values implied that the absorption processes were based on hydrogen bonding. Furthermore, the mechanism of the adsorption of caffeine onto D72 resin was studied by IR spectra and the small molecular model experiments. and the results showed that the adsorption of caffeine onto hydrogen donating adsorbents was based on hydrogen bonding.
