Salzer C A, Elliott C M, Hendrickson S M
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523.
Anal Chem. 1999 Sep 1;71(17):3677-83. doi: 10.1021/ac990139w.
An approach based on rotating ring-disk electrode (RRDE) voltammetry is described for the quantitative, in situ measurement of ion transport between solution and conducting polymer films. The specific composite film studied in this report is polypyrrole/poly(styrenesulfonate) (pPy(+)/pSS(-)). Cation flux in and out of the polymer was obtained from the mass-transport-limited reduction current for the dopant cation(s) measured at the ring during redox cycling of the polymer. Crucial to this method is the use of a supporting electrolyte that is sterically inhibited from passing into the film and the use of dopant ions that adhere to specific electrochemical constraints. With this method it was possible to quantitatively account for all changes in charge compensation in the film by the specific cation(s) involved. Three different cations were explored alone and in paired combinations. Solutions containing mixtures of dopant cations were studied to determine whether the pPy(+)/pSS(-) films exhibit preferential doping. Kinetic factors, likely due to steric differences in the dopant cations, were found to lead to significant preferential doping of the polymer.
本文描述了一种基于旋转环盘电极（RRDE）伏安法的方法，用于定量、原位测量溶液与导电聚合物薄膜之间的离子传输。本报告中研究的特定复合薄膜是聚吡咯/聚（苯乙烯磺酸盐）（pPy(+)/pSS(-)）。在聚合物的氧化还原循环过程中，通过在环上测量的掺杂剂阳离子的传质限制还原电流，可获得聚合物中阳离子的流入和流出通量。该方法的关键在于使用空间位阻抑制其进入薄膜的支持电解质，以及使用符合特定电化学限制的掺杂离子。通过这种方法，可以定量地说明薄膜中由特定阳离子引起的电荷补偿的所有变化。单独研究了三种不同的阳离子，并进行了成对组合研究。对含有掺杂剂阳离子混合物的溶液进行了研究，以确定pPy(+)/pSS(-)薄膜是否表现出优先掺杂。发现可能由于掺杂剂阳离子的空间差异导致的动力学因素，会使聚合物产生显著的优先掺杂。
