Molecular Dynamics Study of Oxygen Scattering Behavior on Perfluorosulfonic Acid Ionomer Thin Films
Molecular Dynamics Study of Oxygen Scattering Behavior on Perfluorosulfonic Acid Ionomer Thin Films
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DOI：
10.1021/acs.jpcc.8b11475
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
M. Nakauchi;T. Mabuchi;Yuta Yoshimoto;T. Hori;I. Kinefuchi;H. Takeuchi;T. Tokumasu
中科院分区：
文献类型：
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作者：
M. Nakauchi;T. Mabuchi;Yuta Yoshimoto;T. Hori;I. Kinefuchi;H. Takeuchi;T. Tokumasu
用分子动力学模拟方法研究了氧分子在全氟磺酸(PFSA)离聚体薄膜上的散射动力学。我们在300K的碳表面制备了不同水分含量的PFSA离聚体薄膜，然后在150~600K的温度范围内，以不同的入射角度和入射能量将氧分子注入到薄膜中，薄膜对气体-表面碰撞的有效柔软度随着薄膜水合程度的增加而增加。由于聚合物的缠绕和水分子的流动性，暴露在PFSA聚合物和水分子表面的区域具有不同的柔软性。全氟辛烷磺酸聚合物使表面比水分子更坚硬，导致在碰撞过程中氧气分子的适应能力较差。相比之下，撞击的分子更有可能被困在水分子上，被困的分子比直接从表面反射的分子能更好地适应。安格斯..。
The scattering dynamics of oxygen molecules on perfluorosulfonic acid (PFSA) ionomer thin films was investigated using molecular dynamic simulations. We constructed PFSA ionomer thin films with different water contents on a carbon surface at 300 K and then shot oxygen molecules into the films with different incident angles and incident energies corresponding to a temperature range from 150 to 600 K. The effective softness of the film for gas–surface collisions increased on increasing the hydration level of the film. The surface regions exposing PFSA polymers and water molecules had different softness because of polymer entanglement and the mobility of water molecules, respectively. PFSA polymers make the surface more rigid than water molecules and lead to poor accommodation of oxygen molecules during the collisions. In contrast, impinging molecules are more likely to be trapped on the water molecules and trapped molecules are better accommodated than molecules reflected directly from the surface. The angu...