Cha JinHyeok, Lee Wooju, Baek Jihye
Institute of Fundamental and Advanced Technology, Hyundai Motor Company, 37 Cheoldobangmulgwan-ro, Uiwang-si 16082, Gyeonggi-do, Korea.
Polymers (Basel). 2021 Mar 19;13(6):947. doi: 10.3390/polym13060947.
The advent of the Hydrogen Society created great interest around hydrogen-based energy a decade ago, with several types of vehicles based on hydrogen fuel cells already being produced in the automotive sector. For highly efficient fuel cell systems, the control of hydrogen inside a polymer-based electrolyte membrane is crucial. In this study, we investigated the molecular behavior of hydrogen inside a polymer-based proton-exchange membrane, using quantum and molecular dynamics simulations. In particular, this study focused on the structural difference of the pendent-like side chain polymer, resulting in the penetration ratio of hydrogen into the membrane deriving from the penetration depth of the membrane's thickness while keeping the simulation time constant. The results reveal that the penetration ratio of the polymer with a shorter side chain was higher than that with the longer side chain. This was justified via two perspectives; electrostatic and van der Waals molecular interactions, and the structural difference of the polymers resulting in the free volume and different behavior of the side chain. In conclusion, we found that a longer side chain is more trembling and acts as an obstruction, dominating the penetration of hydrogen inside the polymer membrane.
十年前，氢能社会的出现引发了人们对氢基能源的浓厚兴趣，汽车领域已经在生产几种基于氢燃料电池的车辆。对于高效燃料电池系统，基于聚合物的电解质膜内氢气的控制至关重要。在本研究中，我们使用量子和分子动力学模拟研究了基于聚合物的质子交换膜内氢气的分子行为。特别是，本研究关注悬垂状侧链聚合物的结构差异，在保持模拟时间不变的情况下，氢气进入膜的渗透率源于膜厚度的渗透深度。结果表明，侧链较短的聚合物的渗透率高于侧链较长的聚合物。这从两个角度得到了验证：静电和范德华分子相互作用，以及聚合物的结构差异导致自由体积和侧链行为不同。总之，我们发现较长的侧链更易颤动并起到阻碍作用，主导了氢气在聚合物膜内的渗透。
