Department of Materials Engineering, Monash University, Clayton, VIC 3800, Australia.
J Am Chem Soc. 2013 Jul 31;135(30):11309-13. doi: 10.1021/ja405032c. Epub 2013 Jul 17.
In-situ-polymerized films of poly(3,4-ethylenedioxythiophene) (PEDOT) are known to be relatively ordered materials and maintain this order under changing chemical and electrochemical conditions. It is therefore surprising that certain ionic liquids (ILs) were found to interact with PEDOT and thereby to a large extent disrupt the ordered structure. The current work demonstrates the expansion of the interlayer distance (d100) of PEDOT and the composite of PEDOT with poly(ethyleneglycol) (PEDOT(PTS):PEG) in the presence of IL mixtures containing triisobutylmethylphosphonium tosylate (P1444PTS) and water. In presence of the mixtures, the PEDOT(PTS):PEG film expands up to ~100% while the PEDOT(PTS) film expanded ~50%. The expansion did not increase the electrical resistance but increased the absorption in the π-π* range, which can be explained by increased shielding of the PEDOT chains by the IL. The incorporation of P1444PTS increased the capacitance by 350%, compared to the theoretical capacitance of PEDOT(PTS), due to the formation of additional double-layer capacitance.
原位聚合的聚（3,4-亚乙基二氧噻吩）（PEDOT）薄膜已知是相对有序的材料，并在不断变化的化学和电化学条件下保持这种有序性。因此，某些离子液体（ILs）被发现与 PEDOT 相互作用，从而在很大程度上破坏了有序结构，这令人惊讶。目前的工作表明，PEDOT 及其与聚（乙二醇）（PEDOT（PTS）：PEG）的复合物在含有三异丁基甲基膦酸对甲苯磺酸盐（P1444PTS）和水的 IL 混合物的存在下，层间距离（d100）扩大。在混合物的存在下，PEDOT（PTS）：PEG 薄膜的膨胀率高达约 100%，而 PEDOT（PTS）薄膜的膨胀率高达约 50%。这种膨胀并没有增加电阻，而是增加了π-π*范围内的吸收，这可以解释为 IL 对 PEDOT 链的屏蔽作用增强。与 PEDOT（PTS）的理论电容相比，由于形成了额外的双层电容，P1444PTS 的掺入使电容增加了 350%。
