Gas Adsorption in Nanoporous Materials: Molecular Structure and Recognition

纳米多孔材料中的气体吸附：分子结构与识别

• 批准号: 0114123
• 负责人: Dimitrios Papavassiliou
• 金额: $ 16万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0114123&HistoricalAwards=false
• 关键词: Gas; Adsorption; Nanoporous; Materials; Molecular

ABSTRACT CTS-0114123Lee, Lloyd L/ U of Oklahoma Nanostructured materials are currently being developed for use in molecular adsorption and molecular recognition. The design and selection of sensor materials [65,66] in commercial use have been mostly done by trial and error and qualitative thinking, rather than with tailor-made specificity and quantitative principles. With the development of the nanostructured materials, such as self-assembled monolayers (SAMs) and dendritic structures, there have been created a vast menu of chemical and physical properties for selection. We need to have a molecular level understanding of the nature and consequence of the molecular interactions at play. This research is aimed at establishing a microscopic framework, using molecular theory and computer simulation, for gas adsorption in three typical nanomaterials: aerogels, zeolites, and starburst dendrimers. This furnishes a quantitative principle rooted in the molecular level that shall aid in the design and development of gas adsorption and molecular recognition devices.There are, broadly speaking, older nanomaterials (e.g., zeolites, membranes, aerogels, activated carbons, etc.) and newer ones (e.g., star polymers, dendrimers, etc.) Whathappens to the gases (fluids) included in these substrates with respect to their molecular distributions, isosteric heats of adsorption, phase behavior, thermodynamic properties, adsorption isotherms, separation efficiency (for mixtures), selective adsorption, and partition coefficients? An accurate molecular theory and well-targeted molecular simulation are needed that give the probabilistic densities of distribution of theconfined gases around the ordered substrates, as well as their theoretical connections to the thermodynamic properties. This is properly the task for our statistical mechanics of adsorption.The principal investigator will develop a new integral equation (IE) theory and perform molecular computer simulation to determine the gas structures (distribution functions) and thermodynamic properties of inclusion gases and gas mixtures around nanostructures. He uses the existing replica Ornsterin-Zernike (ROZ) equations as astarting point. New forms will be developed for the inclusion gas in random as well as regular media, and in rigid as well as deformable adsorbents. The conventional ROZ can treat only inrigidlo matrices. He uses a two-temperature quench procedure to formulate a new equation for responsive systems. In addition, consistency is achieved by designing a new closure relation satisfying a set of exact self-consistency principles. The principal investigator stresses that without this closure relation, a good one at that, no integral equations can achieve high consistency, nor accuracy. Monte Carlo molecular simulations and molecular dynamics will be carried out to determine the mechanism of adsorption and to test the theories.

摘要 CTS-0114123Lee, Lloyd L/ U，俄克拉荷马州 纳米结构材料目前正在开发用于分子吸附和分子识别。商业用途的传感器材料的设计和选择[65,66]大多是通过反复试验和定性思维来完成的，而不是采用量身定制的特异性和定量原则。随着自组装单层（SAM）和树枝状结构等纳米结构材料的发展，已经产生了大量的化学和物理性质可供选择。我们需要对分子相互作用的性质和后果有分子水平的理解。本研究旨在利用分子理论和计算机模拟建立气凝胶、沸石和星爆树枝状聚合物三种典型纳米材料中气体吸附的微观框架。这提供了一种植根于分子水平的定量原理，有助于气体吸附和分子识别装置的设计和开发。广义上讲，有较旧的纳米材料（例如沸石、膜、气凝胶、活性炭等）和较新的纳米材料（例如星形聚合物、树枝状聚合物等）。 这些底物的分子分布、等量吸附热、相行为、热力学性质、吸附等温线、分离效率（混合物）、选择性吸附和分配系数？需要精确的分子理论和有针对性的分子模拟来给出有序基底周围封闭气体分布的概率密度，以及它们与热力学性质的理论联系。这正是我们吸附统计力学的任务。首席研究员将开发一种新的积分方程（IE）理论并进行分子计算机模拟，以确定纳米结构周围的夹杂气体和气体混合物的气体结构（分布函数）和热力学性质。 他使用现有的 Ornsterin-Zernike (ROZ) 方程副本作为起点。将为随机和规则介质以及刚性和可变形吸附剂中的夹杂气体开发新形式。传统的ROZ只能处理刚性矩阵。 他使用双温度淬火程序为响应系统制定了一个新方程。此外，一致性是通过设计满足一组精确自洽原则的新闭包关系来实现的。首席研究员强调，如果没有这种闭包关系（一个很好的闭包关系），任何积分方程都无法实现高一致性和准确性。将进行蒙特卡罗分子模拟和分子动力学以确定吸附机理并测试理论。