(中南工业大学 化学化工学院, 长沙 410083)
摘 要: 以转型了的N263Cl, N263I和四丁基碘化铵作为电活性物质, 以聚乙烯醇(PVA)和壳聚糖(CS)作为聚合物支持体, 制成了对铝酸根离子有响应的离子选择性膜电极。其中以N263I制成的膜电极对铝酸根离子的响应较好, 并研究了N263I的用量及转型条件对该膜电极性能的影响。考察了在不同碱度的待测溶液中以及升温条件下,该膜电极的膜电位与铝酸根离子浓度的关系。结果表明,该膜电极在0.01~2 mol/L的浓度范围内对铝酸根离子有良好的Nernst响应, 其级差随着温度的升高而增大, 测得常温下膜电位级差约为10.3 mV每10倍浓度变化, 60 ℃时约为15.4 mV每10倍浓度变化, 75 ℃时约为18.3 mV每10倍浓度变化。
关键字: 铝酸根离子; 膜电极; 离子选择性
(College of Chemistry and Chemical Engineering, Central South University of Technology,Changsha 410083, P.R.China)
Abstract:Aluminate anionseletive membrane eletrodes based on 3decylmethyl ammonium chloride(N263C1), 3decylmethyl ammonium iodide(N263I) and 4butyl ammoniumiodide in poly(vinyl alcohol)(PVA) and chitoson(CS) were prepared. The relationship ofmembrane potentials with concentrations of aluminate ion was studied under theconditions of different quaternary ammonium compounds, various alkalinities and various temperatures. The results show that the membrane electrode based on N263Iin PVA and CS has a good Nernst response for aluminate ion in the concentrationrange of 102-~2 mol/L. The slope of the Nernst equation for this electrode increases with temperature. The slope for the electrode based on N263I is 10 mV per decade concentration change, 15.4 mV per decade concentration change and 18.3 mV per decade concentration change at room temperature, 60 ℃ and 75 ℃, respectively. The membrane electrode prepared had good reproducibility and stablility. The common anions have no effect on the electrode response except ClO-4, S2- and F-.
Key words: aluminate ion; membrane electrode; ionic selectivity