Devanathan R, Venkatnathan A, Dupuis M
Fundamental Science Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
J Phys Chem B. 2007 Jul 19;111(28):8069-79. doi: 10.1021/jp0726992. Epub 2007 Jun 20.
We used classical molecular dynamics simulation with the DREIDING force field to characterize the changes in the nanostructure of Nafion membrane brought about by systematically changing the hydration level. We calculated the relative percentages of free, weakly bound, and bound water in hydrated Nafion membranes. At low hydration levels, coordination of hydronium ions by multiple sulfonate groups prevents vehicular transport and impedes structural transport of protons through steric hindrance to hydration of the hydronium ions. Our results provide insights into the nanostructure of hydrated Nafion membrane and are in excellent agreement with experimental observations by neutron scattering of changes in the percentage of non diffusing hydrogen atoms.
我们使用具有DREIDING力场的经典分子动力学模拟来表征通过系统改变水合水平而引起的Nafion膜纳米结构的变化。我们计算了水合Nafion膜中自由水、弱结合水和结合水的相对百分比。在低水合水平下，多个磺酸根基团对水合氢离子的配位作用会阻止离子载体传输，并通过对水合氢离子水合作用的空间位阻来阻碍质子的结构传输。我们的结果为水合Nafion膜的纳米结构提供了见解，并且与通过中子散射对非扩散氢原子百分比变化进行的实验观察结果非常吻合。
