Collaborative Research: Modeling & Model Systems for Adsorbate Behavior in Lateral Confinement

在这个由化学系大分子、超分子和纳米化学计划资助的项目中，马里兰大学的Theodore L.Einstein教授和加州大学河滨分校的Ludwig Bartels教授和他们的学生将结合扫描隧道显微镜和统计力学的方法，特别是蒙特卡罗模拟和晶格气体建模，了解在具有突出金属表面态的衬底上形成的与并苯相关的大型规则自组织网络的形成，以及由此产生的纳米发泡在提供边界以改变小吸附体(如一氧化碳)的排列和反应中所起的作用。与国际合作者一起，他们将测试由于受限气孔中混合熵的改变而改变的(来自大表面的)关键反应速率的理论，并将研究超结构与铜衬底紧密堆积表面上的表面状态的关系，并研究对点诱导气孔形成的简单图像的修正。他们还将利用由电子态主导的二维(2D)材料的研究，这些材料与金属表面状态有许多相似之处。该项目将为研究生和本科生提供最先进的建模和/或实验室经验，他们将学习扫描探针显微镜和互补蒙特卡罗模拟和相关函数的计算，以及从头计算电子结构，以帮助将统计力学研究参数化。该项目包括探索有机分子在具有缓慢衰减的2D电子态的衬底上形成规则的多孔超结构。对二维类量子点态的孔稳定化新解释的验证将继续下去。这些状态对孔内小吸附物(尤其是一氧化碳)分布的影响将被仔细研究。相关参数的计算将需要使用将范德华相互作用纳入密度泛函理论计算的最新进展。通过一位在统计物理方面有经验的理论家的领导，该项目将培养系统的观点，加深对相和图案形成的结果的理解和更快的测试，并预测有前景的替代底物和吸附。这项拟议的工作预计将对工业方法论和整个社会产生影响，因为它提供了访问相同纳米级单元的大阵列的途径，在这些阵列中，人们可以进行相当于并行计算的实验。对这种结构的控制将允许调节细胞大小，以选择有利的配置，增强特定的反应，以及探索自然波动。这项工作还将为具有广泛的国家、国际和社会影响的教育和外展活动提供机会。

In this project, funded by the Macromolecular, Supramolecular and Nanochemistry Program of theChemistry Division, Prof. Theodore L. Einstein of University of Maryland and Prof. Ludwig Bartels ofthe University of California, Riverside, and their students will use a combination of scanning tunnelingmicroscopy and methods of statistical mechanics, especially Monte Carlo simulations and lattice-gasmodeling, to understand the formation of large regular self-organized networks of acene-relatedmolecules on substrates with prominent metallic surface states and the role of the resulting nanoscalepores in providing boundaries that modify the arrangements and reactions of small adsorbates like COtherein. With international collaborators they will test theories of modification (from large surfaces) keyreaction rates because of altered entropy of mixing in the confined pores and will study the relation of thesuperstructure to the surface state on the close-packed face of the copper substrate and investigate thecorrections to a simple picture of dot-induced pore formation. They will also take advantage of research intwo dimensional (2D) materials dominated by electronic states with many similarities to metallic surfacestates.This project will provide state of the art modeling and/or laboratory experiences for graduate andundergraduate students who will be learning the techniques of scanning probe microscopy andcomplementary Monte Carlo simulations and calculations of correlation functions, as well as ab initioelectronic structure calculations to help parameterize the statistical mechanical studies. The projectconsists of an exploration of the formation of regular porous superstructures by organic molecules onsubstrates with slowly decaying 2D electronic states. The validation of the novel explanation of porestabilization by 2D quantum-dot-like states will be pursued. The impact of such states on the distributionof small adsorbates (especially carbon monoxide) within the pore will be scrutinized. Calculations ofassociated parameters will require use of the latest advances in incorporating van der Waals interactionsinto density functional theory computations. Through leadership by a theorist experienced in statisticalphysics, this project will foster systematic perspective, deeper understanding and faster testing of resultsfor phase and pattern formation and predictions promising alternative substrates and adsorbates. Theproposed work is expected to have impact on industrial methodologies and society at large by providingaccess to large arrays of identical nanoscale cells in which one can do the experimental equivalent ofparallel computation. Control of such structures will allow tuning of cell sizes to select for favorableconfigurations and enhance particular reactions, as well as to explore natural fluctuations. The work willalso provide opportunities for educational and outreach activities with proven broad national,international and societal impact.