Oh B K, Kim C Y, Lee H J, Rho K L, Cha G S, Nam H
Department of Chemistry and Research Institute of Basic Science, Kwangwoon University, 447-1 Wolgye-Dong, Nowon-Ku, Seoul 139-701, Korea.
Anal Chem. 1996 Feb 1;68(3):503-8. doi: 10.1021/ac950789+.
New calcium-selective membranes for all-solid-state ion sensors are developed with a highly adhesive one-component room temperature vulcanizing-type silicone rubber (RTV-1-type SR) matrix. The membranes are formulated with 21.6 wt % bis(2-ethylhexyl) adipate, 0.3 wt % tetradodecylammonium tetrakis(p-chlorophenyl)borate (ETH 500), 0.1 wt % potassium tetrakis(p-chlorophenyl)borate, and 0.8 wt % calcium-selective neutral carrier ETH 129 or ETH 1001. Plasticizer added to the RTV-1-type SR matrix not only decreases the bulk membrane resistance but also increases the solubility of electroactive components incorporated in the membrane without significantly deteriorating its adhesive strength. It is found that the lipophilic salt ETH 500 remarkably enhances the calcium selectivity of ETH 129 or ETH 1001 ligands in the SR matrix; the selectivity coefficients ([Formula: see text] by separate solution method, where j = Li(+), Na(+), K(+), or Mg(2+)) for the optimized membranes were below 10(-5). Potentiometric characteristics of planar-type Ag electrodes coated with optimized RTV-1-type SR membranes, e.g., response slope 29.0 ± 0.5 mV/decade, detection limit below 5.0 × 10(-7) M a(Ca)((2+)), and 2-3 mV of potential drift per day, were virtually the same as those of the corresponding poly(vinyl chloride) membrane-based conventional electrodes, but with greatly enhanced sensor-to-sensor reproducibility and lifetime (3-9 weeks).
采用具有高粘性的单组分室温硫化型硅橡胶（RTV - 1型SR）基体，开发了用于全固态离子传感器的新型钙选择性膜。该膜由21.6 wt%的己二酸二（2 - 乙基己基）酯、0.3 wt%的四（对氯苯基）硼酸十四烷基铵（ETH 500）、0.1 wt%的四（对氯苯基）硼酸钾和0.8 wt%的钙选择性中性载体ETH 129或ETH 1001配制而成。添加到RTV - 1型SR基体中的增塑剂不仅降低了膜的体电阻，还提高了掺入膜中的电活性成分的溶解度，而不会显著降低其粘合强度。研究发现，亲脂性盐ETH 500显著提高了SR基体中ETH 129或ETH 1001配体的钙选择性；优化膜的选择性系数（通过单独溶液法测定，其中j = Li(+)、Na(+)、K(+)或Mg(2+)）低于10(-5)。涂覆有优化的RTV - 1型SR膜的平面型银电极的电位特性，例如响应斜率为29.0±0.5 mV/十倍，检测限低于5.0×10(-7) M a(Ca)((2+))，每天电位漂移2 - 3 mV，实际上与相应的基于聚氯乙烯膜的传统电极相同，但传感器之间的重现性和寿命大大提高（3 - 9周）。
