Electrochemical determination of the glass transition temperature of thin polyelectrolyte brushes at solid-liquid interfaces by impedance spectroscopy.
Electrochemical determination of the glass transition temperature of thin polyelectrolyte brushes at solid-liquid interfaces by impedance spectroscopy.
复制标题
通过阻抗谱电化学测定固液界面薄聚电解质刷的玻璃化转变温度。
作者：
Teodoro Alonso;María José Rodríguez;C. Gervasi;S. Moya;O. Azzaroni
设计策略来评估固体电解质界面处的玻璃化转变温度（Tg）对于理解和合理化在宽范围的设置中的玻璃化转变膜的温度依赖性行为是非常重要的。尽管在薄膜配置中在水性条件下测量Tg的重要性的认识不断发展，但其直接测量构成了聚合物和材料科学中仍然难以实现的具有挑战性的情况。在这里，我们描述了一种新的方法的基础上电化学阻抗谱（EIS）来估计平面刷在固液界面的玻璃化转变温度。为了测量Tg，测量扩散通过电刷的氧化还原探针的电荷转移电阻（Rct），并且将对应于Rct的不连续变化的温度确定为Tg。此外，我们证明，阻抗测量不仅有利于Tg的估计，而且还能够可靠地评估聚合物界面的传输特性，即，扩散系数的测定，接近热转变。我们认为这种方法弥合了电化学和聚合物科学中使用的传统工具之间的差距，并提供了新的机会来表征复杂的聚合物界面和大分子组装体的热行为。
Devising strategies to assess the glass transition temperature (Tg) of polyelectrolyte assemblies at solid-electrolyte interfaces is very important to understand and rationalize the temperature-dependent behavior of polyelectrolyte films in a wide range of settings. Despite the evolving perception of the importance of measuring Tg under aqueous conditions in thin film configurations, its straightforward measurement poses a challenging situation that still remains elusive in polymer and materials science. Here, we describe a new method based on electrochemical impedance spectroscopy (EIS) to estimate the glass transition temperature of planar polyelectrolyte brushes at solid-liquid interfaces. To measure Tg, the charge transfer resistance (Rct) of a redox probe diffusing through the polyelectrolyte brush was measured, and the temperature corresponding to the discontinuous change in Rct was identified as Tg. Furthermore, we demonstrate that impedance measurements not only facilitate the estimation of Tg but also enable a reliable evaluation of the transport properties of the polymeric interface, i.e., determination of diffusion coefficients, close to the thermal transition. We consider that this approach bridges the gap between electrochemistry and the traditional tools used in polymer science and offers new opportunities to characterize the thermal behavior of complex polymeric interfaces and macromolecular assemblies.
影响因子：
20.6
作者：
Eckermann AL;Feld DJ;Shaw JA;Meade TJ
通讯作者：
Meade TJ