Departamento de Física Aplicada, Universidad de Salamanca, E-37008 Salamanca, Spain.
J Chem Phys. 2011 Oct 21;135(15):154704. doi: 10.1063/1.3643117.
We show that a simple model consisting of a binary hard-sphere mixture in a narrow cylindrical pore can lead to strong size selectivity by considering a situation where each species of the mixture sees a different radius of the cylinder. Two mechanisms are proposed to explain the observed results depending on the radius of the cylinder: for large radii the selectivity is driven by an enhancement of the depletion forces at the cylinder walls whereas for the narrowest cylinders excluded-volume effects lead to a shift of the effective chemical potential of the particles in the pore.
我们展示了一个简单的模型，该模型由狭窄圆柱孔中的二元硬球混合物组成，通过考虑混合物的每种物质看到不同的圆柱半径，可以导致强烈的尺寸选择性。提出了两种机制来解释观察到的结果，这取决于圆柱的半径：对于较大的半径，选择性是由圆柱壁上的耗尽力增强驱动的；而对于最窄的圆柱，排除体积效应导致颗粒在孔中的有效化学势发生转移。
