Conducting polymers display a range of interesting properties, from electrical conduction to tunable optical absorption and mechanical flexibility, to name but a few. Their properties arise from positive charges (carbocations) on their conjugated backbone that are stabilised by counterions doped in the polymer matrix. In this research we report hydrolysis of these carbocations when poly(3,4-ethylenedioxy thiophene) is exposed to 1 mM aqueous salt solutions. Remarkably, two classes of anion interactions are revealed; anions that oxidise PEDOT via a doping process, and those that facilitate the S_N1 hydrolysis of the carbocation to create hydroxylated PEDOT. A pKa of 6.4 for the conjugate acid of the anion approximately marks the transition between chemical oxidation and hydrolysis. PEDOT can be cycled between hydrolysis and oxidation by alternating exposure to different salt solutions. This has ramifications for using doped conducting polymers in aqueous environments (such as sensing, energy storage and biomedical devices).

导电聚合物显示出一系列有趣的特性，从导电到可调光吸收和机械柔韧性，仅举几例。它们的特性源于其共轭主链上的正电荷（碳阳离子），这些主链被聚合物基质中掺杂的抗衡离子稳定。在这项研究中，我们报告了聚（3,4-乙二氧基噻吩）暴露于 1 mM 盐水溶液时这些碳正离子的水解。值得注意的是，揭示了两类阴离子相互作用；通过掺杂过程氧化 PEDOT 的阴离子，以及促进 S _N1 碳正离子水解生成羟基化 PEDOT。阴离子共轭酸的 pKa 为 6.4 大约标志着化学氧化和水解之间的转变。通过交替暴露于不同的盐溶液，PEDOT 可以在水解和氧化之间循环。这对在水性环境（例如传感、储能和生物医学设备）中使用掺杂的导电聚合物有影响。