Advanced Materials Research Laboratories, Toray Industries, Inc., 2-1 Sonoyama 3-chome, Otsu, Shiga 520-0842, Japan.
Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
J Chem Phys. 2018 Jun 7;148(21):214903. doi: 10.1063/1.5018884.
Ionomers play a key role in forming the catalyst layer of polymer electrolyte fuel cells. In the present work, we performed atomistic molecular dynamics simulations and free-energy calculations with the energy-representation method for sulfonated polyethersulfone (SPES) and its derivatives toward the rational design of ionomers for carbon alloy catalysts. It was observed that HO aggregates strongly in the branched SPES systems with fluorocarbons and is located homogeneously in the systems without fluorocarbons. The O permeability was then examined within the framework of the solubility-diffusion mechanism. The permeability was seen to be large for the branched SPES with fluorocarbons, indicating that the performance of ionomers as a permeation medium for O may be tuned by the flexibility and branching of the polymer chain.
离聚物在形成聚合物电解质燃料电池的催化剂层中起着关键作用。在本工作中，我们采用能量表象法进行了磺化聚醚砜（SPES）及其衍生物的原子分子动力学模拟和自由能计算，以期为碳合金催化剂的离聚物进行合理设计。结果表明，HO 在含氟碳的支化 SPES 体系中强烈聚集，并均匀地位于不含氟碳的体系中。然后，在溶解-扩散机制的框架内考察了 O 的渗透率。对于含氟碳的支化 SPES，渗透率较大，表明离聚物作为 O 渗透介质的性能可以通过聚合物链的柔韧性和支化来调节。
