Woo Hyung-June, Porcheron F, Monson P A
Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Langmuir. 2004 May 25;20(11):4743-7. doi: 10.1021/la035999t.
The desorption mechanism of fluids in disordered mesoporous glasses is studied by Monte Carlo simulations of a coarse-grained lattice model with realistic matrix configurations representative of Vycor. Two methods of simulation are considered: grand canonical ensemble Monte Carlo simulations and dynamic Monte Carlo simulations which mimic the diffusion of the fluid in and out of the material using Kawasaki dynamics. In the grand canonical simulations, cavitation via nucleation of bubbles inside the pores plays the dominant role in determining the fluid configurations along the desorption isotherm. The Kawasaki dynamics simulations indicate that such configurations are achieved dynamically via the gradual advancement of macroscopic front interfaces toward the interior. This is made possible by the bubble nucleation mechanism operating on a length scale that is determined by both the typical pore size and the strength of the solid-fluid interaction.
通过对具有代表Vycor的真实基质构型的粗粒化晶格模型进行蒙特卡罗模拟，研究了无序介孔玻璃中流体的解吸机制。考虑了两种模拟方法：巨正则系综蒙特卡罗模拟和动态蒙特卡罗模拟，后者使用川崎动力学模拟流体进出材料的扩散。在巨正则模拟中，孔隙内气泡成核引起的空化在确定解吸等温线上的流体构型方面起主导作用。川崎动力学模拟表明，这种构型是通过宏观前沿界面逐渐向内部推进而动态实现的。这是由气泡成核机制实现的，该机制在一个由典型孔径和固液相互作用强度共同决定的长度尺度上起作用。
