Mechanisms of proton conductance in polymer electrolyte membranes
Mechanisms of proton conductance in polymer electrolyte membranes
复制标题
DOI：
10.1021/jp003182s
复制
发表时间：
2001-05-03
影响因子：
3.3
通讯作者：
Walbran, S
中科院分区：
文献类型：
--
作者：
Eikerling, M;Kornyshev, AA;Walbran, S
我们提供了一个聚合物电解质膜中的质子电导的唯象描述，基于当代的观点，在凝聚介质中的质子转移过程和非均相聚合物电解质膜结构的模型。该描述将单个孔中的质子转移事件与总孔网络性能相结合，从而涉及膜的结构和动力学特性。该理论解决了具体的实验研究的问题，如膜材料的质子定位位点（当量）的密度和孔隙的水含量的影响。特别是分析了在膜溶胀过程中改变的磺酸盐基团之间的平均距离的影响，并且公开了确定宏观膜电导的温度依赖性的因素。从理论得到的特定膜电导率的数值估计与典型的实验数据吻合得很好，从而证实了理论概念的适当性。此外，该模型的多功能性提供了一个有用的和透明的框架相结合的实验数据和分子动力学模拟的结果的分析。
We provide a phenomenological description of proton conductance in polymer electrolyte membranes, based on contemporary views of proton transfer processes in condensed media and a model for heterogeneous polymer electrolyte membrane structure. The description combines the proton transfer events in a single pore with the total pore-network performance and, thereby, relates structural and kinetic characteristics of the membrane. The theory addresses specific experimentally studied issues such as the effect of the density of proton localization sites (equivalent weight) of the membrane material and the water content of the pores. The effect of the average distance between the sulfonate groups, which changes during membrane swelling, is analyzed in particular, and the factors which determine the temperature dependence of the macroscopic membrane conductance are disclosed. Numerical estimates of the specific membrane conductivity obtained from the theory agree very well with typical experimental data, thereby confirming the appropriateness of the theoretical concepts. Moreover, the versatility of the models offers a useful and transparent frame for combining the analysis of both experimental data and the results of molecular dynamics simulations.