Institute for Materials and Processes, School of Engineering, The University of Edinburgh, Edinburgh, United Kingdom.
Langmuir. 2010 Sep 21;26(18):14694-9. doi: 10.1021/la102831e.
Metal-organic frameworks (MOFs) have shown adsorption behavior that is not observed in other microporous materials such as zeolites or activated carbons. This study used grand canonical Monte Carlo simulation to evaluate a particular form of behavior, which corresponds to the presence of unusual type V adsorption isotherms. Study of a series of MOFs in the IRMOF family, containing chemically similar linkers of different length, showed that the presence of type V adsorption depends on a fine balance between the strength of the fluid-fluid and fluid-solid interactions, which in turn is a strong function of the length of the linker and therefore the pore size. A transition from type V behavior to the more common type I behavior is observed as the temperature increases. The temperature at which this transition occurs increases, and the transition becomes more diffuse, as the length of the linker increases. This type V behavior leads to an interesting possibility in the design of MOF adsorbents for use in gas separation and gas storage applications.
金属-有机骨架（MOFs）表现出了在沸石或活性炭等其他微孔材料中观察不到的吸附行为。本研究使用巨正则蒙特卡罗模拟来评估一种特殊的行为形式，这种行为对应于异常的 V 型吸附等温线的存在。对 IRMOF 系列中的一系列 MOFs 的研究表明，V 型吸附的存在取决于流体-流体和流体-固体相互作用强度之间的微妙平衡，而这又强烈依赖于连接体的长度，因此也依赖于孔径。随着温度的升高，观察到从 V 型行为到更常见的 I 型行为的转变。随着连接体长度的增加，这种转变发生的温度升高，并且转变变得更加扩散。这种 V 型行为为设计用于气体分离和气体储存应用的 MOF 吸附剂提供了一个有趣的可能性。
