Hasselt University, B-3590 Diepenbeek, Belgium.
Phys Rev Lett. 2013 Sep 13;111(11):110601. doi: 10.1103/PhysRevLett.111.110601. Epub 2013 Sep 11.
We evaluate the self-diffusion and transport diffusion of interacting particles in a discrete geometry consisting of a linear chain of cavities, with interactions within a cavity described by a free-energy function. Exact analytical expressions are obtained in the absence of correlations, showing that the self-diffusion can exceed the transport diffusion if the free-energy function is concave. The effect of correlations is elucidated by comparison with numerical results. Quantitative agreement is obtained with recent experimental data for diffusion in a nanoporous zeolitic imidazolate framework material, ZIF-8.
我们评估了由腔线性链组成的离散几何中相互作用粒子的自扩散和输运扩散，其中腔内相互作用由自由能函数描述。在不存在相关性的情况下，得到了精确的解析表达式，表明如果自由能函数是凹的，自扩散可以超过输运扩散。通过与数值结果的比较，阐明了相关性的影响。与最近在纳米多孔沸石咪唑酯骨架材料 ZIF-8 中扩散的实验数据进行了定量比较，结果吻合良好。
