The elution of WO ions by NaOH. NaNO3 NaCl and NH4Cl on strong basicanion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied. In addition, the elution curse, the per...The elution of WO ions by NaOH. NaNO3 NaCl and NH4Cl on strong basicanion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied. In addition, the elution curse, the permeation curveand the exchange capacities of operation were presented. The eluate containingtungsten with high content and excessive eluant of low content were obtained by employing the process of eluting using mixed solution of NaCl and NaOH. It's possible to obtain Na2WO4. 2H2O with high purity by evaporating and crystallizing theeluate. The results of mixed elution showed that the diffusion coefficients of Cl-.OH- and WO ions in solution or exchange agent varied due to the coexistence ofcounter ions and then the exchange velocity of WO→Cl- and WOe→OH- wasaccelerated.展开更多
Possibilities for enhancement of catalytic reaction rate by combining phase transfer catalysis and hydrogen bonding of the catalyst with the substrate and reagent were studied. A phase transfer catalyst library with s...Possibilities for enhancement of catalytic reaction rate by combining phase transfer catalysis and hydrogen bonding of the catalyst with the substrate and reagent were studied. A phase transfer catalyst library with sixty polystyrene-supported quaternary ammonium salt catalysts was synthesized. The reduction of acetophenone by NaBH, was used as the probing reaction to select out the most active catalyst in the library by using iterative method, which was the gel-type triethanolamine aminating strongly basic anion exchange resin with the crosslinking degree of 2% A hydrogen bonding assisted catalytic mechanism was proposed to explain the high catalytic activity of the catalyst.展开更多
文摘用一个阴离子树脂交换性能微柱连续测定系统(MCCD),在动态条件下考察影响大孔型强碱阴离子树脂性能的各种因素,得到了测定其交换容量的最佳参数:柱长度为60 mm,内径3.0 mm;树脂层高度40 mm,填充量为0.1720 g;再生剂NaOH浓度3%,流速0.6 m l/m in,再生剂耗量为433 m l/g(树脂);样品水为20 mg/L酸性氯离子溶液,流速1.3 m l/m in。在最佳参数下,对各种大孔型强碱阴离子树脂、凝胶型树脂、均粒与非均粒树脂的交换性能进行了测定和对比;MCCD法与国标法的相关系数为r=0.990,它具有试剂耗量少、操作简单、自动化程度高等优点,通过一次测定,可同时给出树脂的工作交换容量、平衡交换容量、全交换容量、交换速率、利用率等多个参数。
文摘The elution of WO ions by NaOH. NaNO3 NaCl and NH4Cl on strong basicanion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied. In addition, the elution curse, the permeation curveand the exchange capacities of operation were presented. The eluate containingtungsten with high content and excessive eluant of low content were obtained by employing the process of eluting using mixed solution of NaCl and NaOH. It's possible to obtain Na2WO4. 2H2O with high purity by evaporating and crystallizing theeluate. The results of mixed elution showed that the diffusion coefficients of Cl-.OH- and WO ions in solution or exchange agent varied due to the coexistence ofcounter ions and then the exchange velocity of WO→Cl- and WOe→OH- wasaccelerated.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164 and 29974015)
文摘Possibilities for enhancement of catalytic reaction rate by combining phase transfer catalysis and hydrogen bonding of the catalyst with the substrate and reagent were studied. A phase transfer catalyst library with sixty polystyrene-supported quaternary ammonium salt catalysts was synthesized. The reduction of acetophenone by NaBH, was used as the probing reaction to select out the most active catalyst in the library by using iterative method, which was the gel-type triethanolamine aminating strongly basic anion exchange resin with the crosslinking degree of 2% A hydrogen bonding assisted catalytic mechanism was proposed to explain the high catalytic activity of the catalyst.
