Molecular dynamics simulation on the effect of water uptake on hydrogen bond network for OH− conduction in imidazolium-g-PPO membrane
Molecular dynamics simulation on the effect of water uptake on hydrogen bond network for OH− conduction in imidazolium-g-PPO membrane
复制标题
咪唑鎓接枝聚氧化丙烯（imidazolium-g-PPO）膜中吸水对氢氧根传导氢键网络影响的分子动力学模拟
DOI：
10.1016/j.ijhydene.2018.12.090
复制
发表时间：
2019-02
影响因子：
7.2
通讯作者：
Jun Huo;Wen-bo Qi;Hongda Zhu;Boyun Yang;G. He;J. Bao;Xiaopeng Zhang;Xiaoming Yan;Li Gao
中科院分区：
文献类型：
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作者：
Jun Huo;Wen-bo Qi;Hongda Zhu;Boyun Yang;G. He;J. Bao;Xiaopeng Zhang;Xiaoming Yan;Li Gao
阴离子交换膜亲水通道中的OH−传导强烈依赖于水的吸收。为了研究吸水率对OH−传导氢键网络的影响，对具有不同吸水率的水合咪唑-g-PPO膜进行了一系列基于全原子力场的分子动力学模拟。通过将膜密度和OH−电导率与先前的实验进行比较，很好地验证了该系统。利用局部结构性质和对势能，确定了合理的氢键判据来描述膜中的氢键网络。增加水的吸收增强了水和OH−的水合结构，并促进了氢键网络的重组。当吸水量达到λ = 10时，水和OH−几乎饱和，产生了连接良好的氢键网络。进一步增加水吸收对改善氢键网络的贡献要小得多，但不可避免地使膜通道溶胀。这项工作提供了一个分子水平的洞察力的影响，水吸收的氢键结构和动力学的OH-和水限制在咪唑-g-PPO膜。
OH−conduction involved in the hydrophilic channel of anion exchange membrane strongly depends on the water uptake. To investigate the effect of water uptake on the hydrogen bond network for OH−conduction, a series of molecular dynamics simulations based on all-atom force field were performed on the hydrated imidazolium-g-PPO membranes with different water uptakes. The systems were well verified by comparing the membrane density and OH−conductivity with previous experiments. By means of local structural properties and pair-potential energy, reasonable hydrogen bond criteria were determined to describe the hydrogen bond network confined in the membrane. Increasing water uptake enhances the hydration structures of water and OH−, and facilitates the reorganization of the hydrogen bond network. Water and OH−are nearly saturated with water when the water uptake reaches λ = 10, where well-connected hydrogen bond network is produced. Further increasing water uptake has much less contribution to improving the hydrogen bond network, but inevitably swells the membrane channel. This work provides a molecular-level insight into the effect of water uptake on the hydrogen bonding structures and dynamics of OH−and water confined in the imidazolium-g-PPO membrane.