锂离子选择电极的研究 Ⅲ.开链聚醚三(二环己酰胺)锂电极的制备和应用

Studies on Lithium Ion-Selective Electrodes Ⅲ. Preparation and Application of Li^+-Electrodes Based on Non-Cyclic Polyether Tris (dicyclohexylamide) s

以合成的开链聚醚三(二环己酰胺)等中性载体制成了PVC膜Li^+电极,研究了载体结构、膜成分与电极性能的关系,在聚醚三酰胺的胺基中,以环己基取代直链的烷基,显著地改善了Li^+—载体的性能,以邻苯二甲酸二癸酯或其和二苄醚混合增塑的1,1,1—三[1′—(2′—氧杂—3′—二环己胺基羰基)丙基]丙烷Li^+—电极的线性响应范围为2×10^(-5)～10^(-1)mol/L LiCl,K_(Li+Na)^(pot)～8×10^(-3),以Mg(Ac)_2为离子强度调节缓冲剂,用标准比较法或样品加入法测定了LiCl—HCl—H_2O或LiCl—MgCl_2—HCl—H_2O体系中的Li^+,LiCl含量≥2％的样品,测定误差≤5％。

PVC membrabe Li^+-electrodes based on non-cyclic polyether tris (dicyclohexylamide)s and trisamides were prepared. The relationship between the structure of the carriers and performance of these electrodes as well as the effect of the composition of the membrane were investigated. As the Li^+-ionophore, the polyether tris (dicyelohexylamide) s, of which the dicyclohexyl group is substituted for the alkyl group of the trisamides, is better than the polyether trisamides, The selectivity for Li^+ against the other cations increased with improving the lipophilicity of the carriers. The linear response range of Li electrode based on 1, 1, 1-tris [1′- (2′-oxa-3′-dicyclohexylamide) propy]-propane as the neutral carrier and DDP or DDP+DBE as plasticizing solvent is from 2×10^(-5) to 10^(-1) mol/L, K_(LiNa)^(pot)=8×10(-3). The methods for the rapid determination of Li^+ in the LiCI-HCI-H_2O and LiCI-MgCl_2-HCI-H_2O systems by the standard calibration or the analate addition have been developed by using Mg (AC)_2 solution as the ionic strength adjustment buffer. The relative errors are less than 5％ for the synthetic samples of LiCI≥2％.