新型胍盐离子液体剪切粘度性质的预测

Shear Viscosity Calculation of Novel Guanidinium-Based Ionic Liquids

[guanidinium]+[Tf2N]-是一类可应用于锂离子电池电解液的新型胍盐离子液体.针对该类九种胍盐离子液体,基于全原子分子力场,采用非平衡分子动力学(周期性微扰方法)对其剪切粘度进行了计算和预测.讨论了模拟尺寸、稳态速度场以及力场参数对模拟结果的影响.计算结果很好的体现出剪切粘度系数随着温度以及分子尺寸大小的变化趋势.利用周期性微扰线性外推的方法计算得到的粘度系数与实验值吻合良好,在353K下的最大偏差在12%以内.

Shear viscosities were computed for nine novel [guanidinium]＋[Tf2N]-ionic liquids by using non-equilibrium molecular dynamics （MD） （periodic perturbation method） method. The impact of simulation box sizes,steady-state velocity profiles and force field quality on calculated viscosity values are discussed. The simulations quantitatively capture the temperature and molecule-size dependence of viscosities. The calculated viscosities using extrapolation protocol are in good agreement with experimental data. The relative errors are within 12% at 353 K.