Wongkoblap Atichat, Do Duong D
Department of Chemical Engineering, University of Queensland, St Lucia, Queensland 4072, Australia.
J Phys Chem B. 2007 Dec 20;111(50):13949-56. doi: 10.1021/jp0747297. Epub 2007 Nov 29.
The effects of surface dimensions and topology on the adsorption of water on a graphite surface at 298 K were investigated using the grand canonical Monte Carlo (GCMC) simulation. Regarding the surface topology, we specifically considered the functional group and its position on the surface. The hydroxyl group (OH) is used as a model for the functional group. For describing the interaction of water, we used the potential model proposed by Muller et al., and the simulated isotherms of water in slit pores are found to depend on the position and concentration of the functional group. The onset of adsorption shifts to lower pressure when the concentration of functional group increases or when the functional group is positioned at the center of the graphene surface. The configuration of a group of functional groups also affects the adsorption isotherm. In all cases investigated, we have found that the hysteresis loop always exists, and the loop size depends on the concentration of the functional group and its position. Finally, we tested the molecular model of water adsorption on a functional graphite pore against the experimental data of a commercial activated carbon. The agreement is found to be satisfactory when the model porous solid is composed of pores having width in the range between 10 and 20 A and functional groups positioned at the center of the graphitic wall.
使用巨正则蒙特卡罗（GCMC）模拟研究了298K下表面尺寸和拓扑结构对石墨表面水吸附的影响。关于表面拓扑结构，我们特别考虑了官能团及其在表面上的位置。羟基（OH）用作官能团的模型。为了描述水的相互作用，我们使用了穆勒等人提出的势模型，发现狭缝孔中水的模拟等温线取决于官能团的位置和浓度。当官能团浓度增加或官能团位于石墨烯表面中心时，吸附起始点向较低压力移动。一组官能团的构型也会影响吸附等温线。在所研究的所有情况下，我们发现滞后回线总是存在，并且回线大小取决于官能团的浓度及其位置。最后，我们根据商业活性炭的实验数据测试了功能化石墨孔上水吸附的分子模型。当模型多孔固体由宽度在10至20埃范围内的孔和位于石墨壁中心的官能团组成时，发现一致性令人满意。
