GOALI: Molecular Modeling of Confined Nano-Phases and Nano-Porous Materials

摘要 CTS-9908535 Gubbins, K./N. C. 状态 活性炭是所有工业吸附剂中使用最广泛的。它们有两个主要优点：（a）它们很便宜，因为它们是由容易获得的材料（木材、褐煤等）制成的，（b）它们非常强烈地吸附各种液体和材料，并且具有高度选择性。 后一种特性源于碳原子含量非常高的事实。尽管活性炭具有这些优点，但由于其复杂且无定形的结构，活性炭已被证明非常难以表征。 一般来说，它们既具有微孔（宽度小于 2 nm），也具有一些以复杂的孔结构相连的介孔（大于 2 nm）。 有关该结构的一些信息可以通过小角度 X 射线或中子散射（SAXS 和 SANS）以及高分辨率透射电子显微镜 (HRTEM) 获得。 然而，从实验中得到的结构图并不完整。 为了解释这些材料的其他实验，确定孔径分布，并预测工业中使用的各种化学系统的选择性吸附和孔相变，需要在分子水平上建立真实的碳结构模型。 目前用于此目的的模型（独立狭缝孔阵列）已知过于简化，并且对于工业需求来说过于粗糙。我们最近开发了基于分子模拟的协议，以在原子水平上构建更真实的碳模型。 这些基于逆蒙特卡罗，它将模型的结构与结构因子（SAXS 或 SANS）和来自实验的 HRTEM 数据进行匹配。 由此产生的模型与碳的其他实验测量非常吻合，并且有充分的理由相信它们是真实材料的相当准确的表示。长期目标是使用这些模拟方法构建材料数据库，该数据库可用于匹配特定工业碳的数据。 这样的数据库可用于表征各种碳，并随后预测它们的吸附和分离行为。合成这些碳的大部分专业知识以及大部分表征和吸附数据都存在于工业中。 我们需要访问这些材料的样本，特别是有关建模未来方向的建议，以确保我们的研究遵循对行业最相关和最有用的方向。 Westvaco 是这些碳的全球主要生产商。 Westvaco 查尔斯顿技术中心拥有许多活性炭合成和表征方面的领先专家，特别是： 研究化学家 Jacek Jagiello 博士

ABSTRACT CTS-9908535 Gubbins, K./N. C. State Activated carbons are the most widely used of all industrial adsorbents. They have two main advantages: (a) they are cheap, since they are made from readily available materials (wood, lignite, etc.), (b) they adsorb a wide range of fluids and materials very strongly, and are highly selective. The latter property derives from the fact that the carbon atoms are very high.Despite these advantages, activated carbons have proved very difficult to characterize because of their complex and amorphous structure. In general they possess both micropores (less than 2 nm in width) and also some mesopores (larger than 2 nm) linked in a complex pore structure. Some information on this structure can be obtained from small angle x-ray or neutron scattering (SAXS and SANS), and from high resolution transmission electron microscopy (HRTEM). However, the picture of the structure is incomplete from experiment. A realistic structural model of the carbon, at the molecular level, is needed in order to interpret other experiment on these materials, to determine pore size distributions, and to predict selective adsorption and pore phase transitions for the wide range of chemical systems used in industry. The current models used for thispurpose (arrays of independent slit pores) are known to be much over simplified, and are too crude for industrial needs. We have recently developed protocols based on molecular simulation to construct much more realistic models of carbons at the atomic level. These are based on Reverse Monte Carlo, which matches the structure of the model to the structure factor (SAXS or SANS) and HRTEM data from experiment. The resulting models agree well with other experimental measures of the carbons, and there is good reason to believe that they are quite accurate representations of the real materials, A long range goal is to use these simulation methods to construct a data bank of materials which could be used to match data for particular industrial carbons. Such a data bank can be used for characterization of a wide range of carbons, and subsequent prediction of their adsorption and separation behavior.Most of the expertise for synthesizing these carbons, and in addition most of the characterization and adsorption data, resides in industry. We need access to samples of these materials, and particularly advice on future directions for the modeling, in order to ensure that our research follows directions that are most relevant and useful for industry. Westvaco is a major world producer of these carbons. Westvaco's Charleston Technical Center has a number of leading experts in synthesis and characterization of activated carbons, particularly: Dr. Jacek Jagiello, Research Chemist