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1.
A study of the thermodynamics of ion exchange equilibrium for uni-univalent Cl/I, Cl/Br and uni-divalent Cl/SO 4 2− , Cl/C2O 4 2− reaction systems was carried out using ion exchange resin Indion-830 (Type 1). The equilibrium constant K was calculated by taking into account the activity coefficients of ions both in solution and in the resin phase. For uni-univalent ion exchange reaction systems, the equilibrium constants K′ were also calculated from the mole fraction of ions in the resin phase. The K values calculated for uni-univalent and uni-divalent anion exchange reaction systems increased as the temperature grew, indicating the endothermic character of the exchange reactions with enthalpies of 38.2, 32.3, 7.6, and 11.4 kJ/mol, respectively. The article is published in the original.  相似文献   

2.
In the present investigation, 82Br radioactive isotope was used as a tracer to study the kinetics and mechanism of exchange reaction between an ion exchange resin and an external bromide ion solution. In an attempt to study the reversible bromide ion isotopic exchange reaction kinetics, it was expected that whether the initial step was the exchange of radioactive bromide ions from the solution into the ion exchange resin (forward reaction) or from the ion exchange resin into the solution (reverse reaction), two ion isotopic exchange reactions should occur simultaneously, which was further confirmed by the experimental specific reaction rates of 0.130 and 0.131 min−1, respectively. The results can be used to standardize process parameters so as to optimize the utilization of ion exchange resins in various industrial applications. The text was submitted by the authors in English.  相似文献   

3.
In the present investigation Br-82 radioactive isotope was used as a tracer to study the kinetics of exchange reaction taking place between the ion exchange resin and the external bromide ion solution. In an attempt to study the reversible bromide ion-isotopic exchange reaction kinetics, it was expected that whether the initial step was the exchange of radioactive bromide ions from the solution on to the ion exchange resin (forward reaction), or from the ion exchange resin in to the solution (reverse reaction), the two ion-isotopic exchange reactions should occur simultaneously, which was further confirmed from the values of specific reaction rate 0.122 and 0.123 min−1 respectively obtained under identical experimental conditions. The radioactive tracer technique employed in the present investigation will be useful for characterization of various industrial grade ion exchange resins.  相似文献   

4.
The ion exchange resins Duolite A-161 and Duolite A-162 in bromide form were equilibrated separately with the labeled radioactive bromide ion solution of different concentrations varied from 0.005 to 0.100 M in the temperature range 25.0–45.0°C. The K d values of bromide ions for Duolite A-162 were found to be higher than that for Duolite A-161 under similar experimental conditions. The difference in K d values of bromide ions for these two resins is produced by a swelling pressure depending on the water holding capacities.  相似文献   

5.
Ion exchange equilibrium constant (K) for Cl/Br and Cl/C2O42− system was studied at different temperatures from 30 to 45°C. For both uni-univalent and uni-bivalent exchange systems, the value of K increases with rise in temperature i.e., from 1.16 at 30°C to 2.95 at 45°C for Cl/Br system and 19.5 at 30°C to 30.0 at 45°C for Cl/C2O42− system indicating the endothermic ion exchange reaction. The difference in K values at the same temperature for the two was related to the ionic charge of exchangeable ions in the solution. The article is published in the original.  相似文献   

6.
Some studies on the synthesis of strongly basic acrylate polyfunctional anion-exchange resins designed for the extraction of uranium from uranium ore leaching solutions were performed. The alkylation reaction conditions providing the synthesis of a polyfunctional anion-exchange resin with 55% of strongly basic groups were determined. Its sorption properties were studied using model solutions. The capacity of the alkylated polyfunctional anion-exchange resin with respect to uranium was shown to be highly competitive with foreign analogues using the comparative analysis of its ion-exchange characteristics with the parameters of known ion-exchange resins.  相似文献   

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9.
Determination of ion-exchange equilibrium constant (K) for Cl/I and Cl/C2O42− system was studied at different temperatures from 25 to 45°C and by varying concentration of iodide and oxalate ion solution. For both uni-univalent and uni-bivalent exchange systems, using 0.5 g of ion-exchange resin DUOLITE A-116 (in chloride form), the value of K increases with rise in temperature i.e., from 13.0 at 25°C to 19.05 at 45°C for Cl/I system and 33.0 at 25°C to 63.0 at 45°C for Cl/C2O42− system indicating the endothermic ion-exchange reaction. The difference in K values at the same temperature for the two was related to the ionic charge of exchangeable ions in the solution.  相似文献   

10.
Summary The dependence of the chloride distribution coefficient on the co-ion of solutions of different alkali fluorides, MF, up to 11M is tested on the strongly basic anion-exchange resin AG1-X10. Under the same experimental conditions the distribution coefficient decreases in the following order for M+: Na+>K+>Rb+>Cs+. This can be explained by the different co-ion-chloride interactions. The consequence of this interaction for a chromatographic separation of chloride is shown with 5M KF and CsF solutions, used as eluants. Depending on the fluoride concentration, the distribution coefficient passes through a minimum value to increase again at higher electrolyte concentration. The non-exchange electrolyte in the resin phase is responsible for this effect. In addition, the bromide and the iodide distribution coefficients up to 10M KF solutions are determined. One results is that the selectivity coefficient between halide ions increases at higher electrolyte concentrations.  相似文献   

11.
12.
张明明  江曼曼  梁长海 《催化学报》2013,34(12):2161-2166
以碱性阴离子交换树脂Amberlite IRA-900为载体,Pd(C3H5)(C5H5)为金属有机前体,采用金属有机气相沉积法在室温下制备了Pd@IRA-900多相催化材料.紫外-可见光谱分析证明前体和树脂骨架之间的化学作用以及树脂本身的孔道结构使得Pd纳米粒子均匀分散在载体上.透射电镜结果显示钯纳米粒子的平均尺寸为2.6 nm.在较温和的条件下Pd@IRA-900对多种卤代芳烃和苯硼酸的Suzuki偶联都具有良好的催化活性,并且催化剂重复使用5次之后依然具有很好的活性.此外,对树脂载体进行碱性交换处理后可得到一种双功能催化材料Pd@IRA-900(OH),该催化剂在不加入碱的条件下也可以催化碘苯和苯硼酸的Suzuki偶联反应.  相似文献   

13.
The kinetics of isotope exchange in the238U(VI)-233U(VI)-strongly acidic cation exchanger Ostion KS system was studied in the temperature range 275–307K and for total uranium concentration 2.94·10−4–1.75·10−2 mol·l−1 in UO2(NO3)2 solution. The experimental results were evaluated by means of the “two-film mass-transfer model” and by the use of Fick's diffusion equations which have been proved more suitable for the system studied than McKay's equation. The influence of the temperature was evaluated using the Arrhenius equation. The diffusion character of the process follows also from the value of the activation energy (15.12 kJ·mol−1). In comparison with the UO 2 2+ ↔H+ ion exchange6 the isotope exchange studied is faster and less dependent on temperature (the activation energy is substantially lower).  相似文献   

14.
An automatic, rapid combustion method has been developed for the determination of tritium and14C in singly or doubly labelled organic materials by liquid scintillation counting. The sample is burned in a stream of oxygen. The water formed and its tritium content are retained from the gas stream in an absorber containing a small amount of diethyleneglycol monoethyl ether. Radioactive carbon dioxide, if included in the combustion products, is transferred into 3-methoxypropylamine. The final solutions ready for counting are obtained in less than three minutes. Quantitative collection recoveries for both tritium and14C are achieved and no cross-contamination occurs.  相似文献   

15.
Ion-exclusion/anion-exchange chromatography(IEC/AEC) on a combination of a strongly basic anion-exchange resin in the OH——form with basic eluent has been developed.The separation mechanism is based on the ion-exclusion/penetration effect for cations and the anion-exchange effect for anions to anion-exchange resin phase.This system is useful for simultaneous separation and determination of ammonium ion(NH+4),nitrite ion(NO-2),and nitrate ion(NO-3) in water samples.The resolution of analyte ions can be manipulated by changing the concentration of base in eluent on a polystyrene-divinylbenzene based strongly basic anion-exchange resin column.In this study,several separation columns,which consisted of different particle sizes,different functional groups and different anion-exchange capacities,were compared.As the results,the separation column with the smaller anion-exchange capacity(TSKgel Super IC-Anion) showed well-resolved separation of cations and anions.In the optimization of the basic eluent,lithium hydroxide(LiOH) was used as the eluent and the optimal concentration was concluded to be 2 mmol/L,considering the resolution of analyte ions and the whole retention times.In the optimal conditions,the relative standard deviations of the peak areas and the retention times of NH+4,NO-2,and NO-3 ranged 1.28%-3.57% and 0.54%-1.55%,respectively.The limits of detection at signal-to-noise of 3 were 4.10 μmol/L for NH+4,1.87 μmol/L for NO-2 and 2.83 μmol/L for NO-3.  相似文献   

16.
In the present investigation, the 82Br radioactive isotope was used as a tracer to study the kinetics and mechanism of the exchange reaction between an ion exchange resin and an external solution of bromide ions. In an attempt to study the reversible bromide isotope exchange reaction kinetics, it was expected that whether the initial step was the exchange of radioactive bromide ions from the solution to the ion exchange resin (forward reaction) or from the ion exchange resin to the solution (reverse reaction), the two ion-isotope exchange reactions should occur simultaneously, which was further confirmed by the experimental values of specific reaction rates, 0.142 and 0.141 min−1, respectively. The results will be useful to standardize the process parameters so as to achieve optimum use of ion exchange resins in various industrial applications. The text was submitted by the authors in English.  相似文献   

17.
Cupric ferrocyanide impregnated Bio-Rad AGMP-1 or Amberlite IRA-904 exhibited an excellent performance and could be repeatedly used for cesium sorption from 3M nitric acid in the presence of trace hydrazine and subsequent cesium desorption with 3–5M nitric acid containing a slight amount of nitrous acid when regeneration of the composite ion exchanger after the desorption was conducted with an acidic hydrazine solution containing cupric ion above 200–250 ppm.  相似文献   

18.
Comments are given on the kinetic studies of isotope exchange in heterogeneous systems, reported in the paper by J. PLICKA, J. CABICAR, A. GOSMAN and K. TAMBERG, published in J. Radioanal. Nucl. Chem., 88 (1985) 325–336. Both experimental procedure and interpretation of the results are discussed.  相似文献   

19.
To explain the mechanism underlying the adsorption of stevia's polar component rebaudioside A in hydrophilic interaction liquid chromatography mode, the characteristics of rebaudioside A adsorption on various resins in an organic‐solvent‐rich system were studied. Among the tested resins, the strongly acidic cation resin FPC11 showed the best adsorption behavior for rebaudioside A. The factors affecting the adsorption kinetics of the resin for rebaudioside A are discussed. The results showed that the pseudo‐second‐order reaction model and intra‐particle diffusion model best described the adsorption kinetics of rebaudioside A on the resin. The adsorption rate was controlled by physical sorption, mainly via electron sharing or electron transfer between the adsorbent and the adsorbate. The adsorption process with multiple stages involved weak initial adsorption behavior. Thermodynamic studies showed that the adsorption of rebaudioside A on the resin was not an ideal monolayer adsorption, but mutual adsorption effects between the adsorbates. The adsorption was a spontaneous, entropy‐increasing endothermic process. The synergistic effect of hydrogen bonding and ion–dipole was a possible driving force.  相似文献   

20.
Further studies on the application of an AER (A(-) form) method broadened the anion exchange scope of representative ionic liquids and bis(imidazolium) systems. Depending on the hydrophobicity nature of the targeted imidazolium species and counteranions, different organic solvents were used to swap halides for assorted anions, proceeding in excellent to quantitative yields.  相似文献   

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