CAREER: Exploring Chemistry at Graphene Oxide Liquid Interfaces

职业：探索氧化石墨烯液体界面的化学

• 批准号: 1845795
• 负责人: Revati Kumar
• 金额: $ 55.07万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1845795&HistoricalAwards=false
• 关键词: CAREER; Exploring; Chemistry; Graphene; Oxide

In this project funded by the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) program of the Chemistry Division, Professor Revati Kumar from Louisiana State University is investigating how liquids interact with a material called graphene oxide or "GO". At the molecular scale, GO can be described as a sheet of carbon atoms linked together, with oxygen atoms attached to carbon atoms in a few places. The sheet-like structure of GO is similar to graphite, another carbon material which is used in lubricants and pencil leads. The "slipperiness" of graphite derives from the tiny sheets of carbon material sliding past each other. Professor Kumar's interest in GO is not for its lubrication abilities, but because it can be used to adsorb other molecules and ions (for example impurities in water), or be used in other technologies like batteries, fuel cells and catalysts. An interesting feature of GO is that its chemical properties are "tunable." That is, by varying the number of oxygen atoms attached to the carbon sheet, different reactivities result. Professor Kumar and her students are developing computer models to simulate the properties and behavior of various kinds of GO, and their interactions with different molecules and liquids. Graduate and undergraduate students working on this project are being trained in theoretical and computational chemistry ranging from fundamental concepts in statistical mechanics and quantum mechanics to computational algorithms and modeling. Professor Kumar develops molecular simulation modules as part of the undergraduate physical chemistry curriculum at her university. This course provides a basis for her international course on computational methods targeting graduate students and postdoctoral students to help them understand the state-of-the-art computational methods used in the field. Professor Kumar is also involved in K-12 science activities such as Super Science Saturday and Martin Luther King, Jr. Day initiatives. She develops "Fun with molecules", a series of presentations and hands-on learning modules for high school and middle school students that introduce underrepresented minority students to STEM careers. This project focuses on chemical reactivity and dynamics at solid-liquid interfaces. Graphene oxide (GO) is model surface system because it contains both hydrophobic and hydrophilic domains. This nano-scale heterogeneity leads to asymmetrical solvation environments, and a general condition where chemical adsorption and reactivity differ from one interfacial site to the next. The oxygen content of GO can be varied over a wide range, making GO a "tunable" material. This project uses computational molecular dynamics tools to explore the effect of oxygen content on interfacial structural and dynamical heterogeneity. Three specific themes that are critical for GO-based technologies are being explored, namely, the competition between hydrophobic and hydrophilic domains on solvation environment and dynamics, reactivity at these interfaces, and structuring at the electrode-electrolyte interface. The development of accurate yet efficient many-body, all atom force-fields as well as molecular interpretations of experimental data are key aspects of this project. Reactive force-fields based on the chemically intuitive empirical valence bond approach to model acid-base reactivity of GO membranes are also being developed.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在这个由化学部化学结构、动力学和机理-A (CSDM-A) 项目资助的项目中，路易斯安那州立大学的 Revati Kumar 教授正在研究液体如何与氧化石墨烯或“GO”材料相互作用。在分子尺度上，GO可以被描述为一片连接在一起的碳原子，氧原子在一些地方附着在碳原子上。 GO 的片状结构类似于石墨，石墨是另一种用于润滑剂和铅笔芯的碳材料。石墨的“光滑性”源于碳材料的微小片材之间的相互滑动。 Kumar 教授对 GO 的兴趣不是因为它的润滑能力，而是因为它可以用来吸附其他分子和离子（例如水中的杂质），或者用于电池、燃料电池和催化剂等其他技术。 GO 的一个有趣的特点是它的化学性质是“可调的”。 也就是说，通过改变附着在碳片上的氧原子的数量，会产生不同的反应性。 Kumar 教授和她的学生正在开发计算机模型来模拟各种 GO 的特性和行为，以及它们与不同分子和液体的相互作用。 从事该项目的研究生和本科生正在接受理论和计算化学方面的培训，范围从统计力学和量子力学的基本概念到计算算法和建模。库马尔教授开发了分子模拟模块，作为她大学本科物理化学课程的一部分。本课程为她针对研究生和博士后的计算方法国际课程奠定了基础，帮助他们了解该领域使用的最先进的计算方法。 库马尔教授还参与了 K-12 科学活动，例如“超级科学周六”和“马丁·路德·金日”活动。她为高中生和中学生开发了“分子的乐趣”，这是一系列演示和实践学习模块，向代表性不足的少数族裔学生介绍 STEM 职业。该项目重点研究固液界面的化学反应性和动力学。氧化石墨烯 (GO) 是模型表面系统，因为它同时包含疏水域和亲水域。这种纳米级的异质性导致不对称的溶剂化环境，以及化学吸附和反应性从一个界面位点到下一个界面位点不同的一般情况。 GO 的氧含量可以在很大范围内变化，这使得 GO 成为一种“可调”材料。该项目使用计算分子动力学工具来探索氧含量对界面结构和动力学异质性的影响。正在探索对于基于GO的技术至关重要的三个具体主题，即疏水性和亲水性域之间在溶剂化环境和动力学上的竞争、这些界面的反应性以及电极-电解质界面的结构。准确而高效的多体、全原子力场的开发以及实验数据的分子解释是该项目的关键方面。基于化学直观经验价键方法的反应力场也正在开发中，以模拟 GO 膜的酸碱反应性。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响进行评估，被认为值得支持审查标准。

项目成果

Reactive events at the graphene oxide–water interface

氧化石墨烯与水界面的反应事件

• DOI: 10.1039/d1cc04589j
• 发表时间: 2021-11
• 期刊: Chemical Communications
• 影响因子: 4.9
• 作者: David, Rolf;Kumar, Revati
• 通讯作者: Kumar, Revati

Effect of Oxidation Level on the Interfacial Water at the Graphene Oxide–Water Interface: From Spectroscopic Signatures to Hydrogen-Bonding Environment

氧化水平对氧化石墨烯与水界面处界面水的影响：从光谱特征到氢键环境

• DOI: 10.1021/acs.jpcb.0c05282
• 发表时间: 2020-09-17
• 期刊: The Journal of Physical Chemistry. B
• 作者: David R;Tuladhar A;Zhang L;Arges C;Kumar R
• 通讯作者: Kumar R

Adsorption Studies at the Graphene Oxide–Liquid Interface: A Molecular Dynamics Study

氧化石墨烯与液体界面的吸附研究：分子动力学研究

• DOI: 10.1021/acs.jpcc.2c07080
• 发表时间: 2023-03-30
• 期刊: The Journal of Physical Chemistry. C, Nanomaterials and Interfaces
• 影响因子: 3.7
• 作者: Don, Visal Subasinghege;Kim, Lukas;David, Rolf;Nauman, Julia A.;Kumar, Revati
• 通讯作者: Kumar, Revati