Capillary Condensation and Evaporation in Irregular Channels: Sorption Isotherm for Serially Connected Pore Model
Capillary Condensation and Evaporation in Irregular Channels: Sorption Isotherm for Serially Connected Pore Model
复制标题
DOI：
10.1021/acs.jpcc.9b03626
复制
发表时间：
2019-06
期刊：
影响因子：
--
通讯作者：
D. Schneider;R. Valiullin
中科院分区：
文献类型：
--
作者：
D. Schneider;R. Valiullin
几何无序可以强烈地影响介孔固体中流体的相平衡。对于结构无序如何导致相变中协同效应的出现，目前还没有足够的认识。为了解决这个问题，需要理解成核和相生长以及孔隙空间形态之间的复杂相互作用。我们使用统计无序链的串联连接的单孔与不同的孔径来模仿几何无序和解决问题，使用统计热力学方法。作为主要结果，我们导出了在任何热力学条件下，包括滞后区内所有状态的平均相组成的精确解，即，包括扫描等温线的整个吸附等温线族。我们表明，我们的方法正确地再现计算建模的结果，使用平均场理论的晶格气在不规则的模型孔隙。该理论可直接应用于分析。
Geometrical disorder can strongly impact phase equilibria of fluids in mesoporous solids. There is insufficient knowledge of how the structural disorder results in the emergence of the cooperativity effects in phase transitions. To tackle this problem, understanding of the complex interplay between nucleation and phase growth and the pore space morphology is needed. We use statistically disordered chains of serially connected single pores with varying pore sizes to mimic geometric disorder and solve the problem using a statistical thermodynamics approach. As the main result, we derive the exact solution for the average phase composition at any thermodynamic condition including all states within the hysteresis region, i.e., the entire family of the sorption isotherms including the scanning isotherms. We show that our approach correctly reproduces the results of computational modeling using the mean field theory of lattice gas in irregular model pores. The theory developed is directly applicable to the anal...