Horikawa Toshihide, Zeng Yonghong, Do D D, Sotowa Ken-Ichiro, Alcántara Avila Jesús Rafael
Department of Advanced Materials, Institute of Technology and Science, The University of Tokushima, 2-1 Minamijosanjima, Tokushima 770-8506, Japan.
School of Chemical Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia.
J Colloid Interface Sci. 2015 Feb 1;439:1-6. doi: 10.1016/j.jcis.2014.10.024. Epub 2014 Oct 23.
Isosteric heat of adsorption is indispensable in probing the energetic behavior of interaction between adsorbate and solid, and it can shed insight into how molecules interact with a solid by studying the dependence of isosteric heat on loading. In this study, we illustrated how this can be used to explain the difference between adsorption of non-polar (and weakly polar) fluids and strong polar fluids on a highly graphitized carbon black, Carbopack F. This carbon black has a very small quantity of functional group, and interestingly we showed that no matter how small it is the analysis of the isosteric heat versus loading can identify its presence and how it affects the way polar molecules adsorb. We used argon and nitrogen as representatives of non-polar fluid and weakly polar fluid, and methanol and water for strong polar fluid. The pattern of the isosteric heat versus loading can be regarded as a fingerprint to determine the mechanism of adsorption for strong polar fluids, which is very distinct from that for non-polar fluids. This also allows us to estimate the interplay between the various interactions: fluid-fluid, fluid-basal plane and fluid-functional group.
吸附等量热对于探究吸附质与固体之间相互作用的能量行为不可或缺，通过研究吸附等量热对负载量的依赖性，它能够深入了解分子与固体的相互作用方式。在本研究中，我们阐述了如何利用这一点来解释非极性（及弱极性）流体和强极性流体在高度石墨化炭黑Carbopack F上吸附的差异。这种炭黑含有极少量的官能团，有趣的是，我们表明无论其含量多么少，对吸附等量热与负载量的分析都能够识别其存在以及它如何影响极性分子的吸附方式。我们使用氩气和氮气作为非极性流体和弱极性流体的代表，甲醇和水作为强极性流体的代表。吸附等量热与负载量的模式可被视为确定强极性流体吸附机制的指纹图谱，这与非极性流体的模式截然不同。这也使我们能够估计各种相互作用之间的相互影响：流体-流体、流体-基面和流体-官能团之间的相互作用。
