Department of Materials Engineering, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA.
Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
J Chem Phys. 2014 Jan 7;140(1):014902. doi: 10.1063/1.4855715.
We have investigated the ion dynamics in lithium-neutralized 2-pentylheptanoic acid, a small molecule analogue of a precise poly(ethylene-co-acrylic acid) lithium ionomer. Atomistic molecular dynamics simulations were performed in an external electric field. The electric field causes alignment of the ionic aggregates along the field direction. The energetic response of the system to an imposed oscillating electric field for a wide range of frequencies was tracked by monitoring the coulombic contribution to the energy. The susceptibility found in this manner is a component of the dielectric susceptibility typically measured experimentally. A dynamic transition is found and the frequency associated with this transition varies with temperature in an Arrhenius manner. The transition is observed to be associated with rearrangements of the ionic aggregates.
我们研究了锂中和的 2-戊基庚酸中的离子动力学，这是一个精确的聚（乙烯-co-丙烯酸）锂离聚物的小分子类似物。在外部电场中进行了原子分子动力学模拟。电场导致离子聚集体沿着场的方向排列。通过监测对能量的库仑贡献，跟踪了系统对施加的振荡电场在很宽的频率范围内的能量响应。以这种方式找到的磁化率是通常在实验中测量的介电常数的一个分量。发现了一个动态转变，并且与该转变相关的频率以阿伦尼乌斯方式随温度变化。观察到该转变与离子聚集体的重排有关。
