论文总字数：20395字

摘 要

由于氧化石墨烯(GO)在液-液界面具有良好的性能和广泛的应用前景，所以如何高效简单且大规模的在液-液界面制备石墨烯薄膜也成为了研究者所探索的一个重要问题。目前在液-液界面成膜的方法，例如：BF自组装，二维界面诱导组装等，但对于GO吸附到液-液界面的机理还未得到完整的研究。所以需要深入的了解GO在液-液界面的行为才能够帮助指导各种新型碳纳米结构的制备以及应用。

因此本研究采用了分子动力学(MD)模拟来研究GO在液-液界面的吸附行为，使用LAMMPS仿真软件包和LINUX操作系统进行数据分析和构建模型，主要对GO板上含氧官能团的浓度和不同的官能团的影响进行了考虑，计算GO在液-液界面的平均力势(PMF)。研究结果表明GO吸附到液-液界面的过程都是自发进行的，并且都是先以一定的角度进入界面之后再平铺于界面上。而GO板吸附到液-液界面的困难程度和GO表面的氧化程度成正比；同时当加入更亲水的羧基官能团时，GO吸附到液-液界面的困难程度也增大。

关键词：氧化石墨烯 自组装 PMF 液-液界面 分子动力学模拟

Molecular Dynamics Simulation of the Behavior of Graphene Oxide at Liquid-Liquid Interface

ABSTRACT

As graphene oxide (GO) has a good performance and wide application prospect in liquid-liquid interface, how to prepare graphene film efficiently, simply and on a large scale at the liquid-liquid interface has also become an important problem for researchers. At present, the methods of film formation at the liquid-liquid interface, such as BF self-assembly, two-dimensional interface induced assembly, etc., have not been fully studied on the mechanism of the adsorption of GO to the liquid-liquid interface. Therefore, it is necessary to understand the behavior of GO at the liquid-liquid interface to help guide the preparation and application of various new carbon nanostructures.

Therefore, molecular dynamics (MD) simulation is used to study the adsorption behavior of GO at the liquid-liquid interface in this study. The data analysis and model construction are carried out by using LAMMPS simulation software package and LINUX operating system, mainly considering the concentration of oxygen-containing functional groups on GO board and the influence of different functional groups, The mean force potential (PMF) of GO at the liquid-liquid interface is calculated. The results show that the adsorption process of GO to the liquid-liquid interface is spontaneous, and all of them enter the interface at a certain angle and then spread on the interface. The difficulty of adsorption of GO to the liquid-liquid interface is directly proportional to the degree of oxidation on the surface of GO, and the difficulty of adsorption of GO to the liquid-liquid interface is also increased when more hydrophilic carboxyl functional groups are added.

Key Words: Graphene oxide; Self-Assembly; PMF; Liquid-Liquid interface; Molecular dynamics simulation

目 录

摘要 I

ABSTRACT II

第一章 绪论 1

1.1引言 1

1.2氧化石墨烯的制备 2

1.3氧化石墨烯的化学结构 3

1.4氧化石墨烯的性质和特点 4

1.5氧化石墨烯的应用 4

1.5.1纳米复合材料 4

1.5.2电化学 5

1.5.3膜材料 5

1.6氧化石墨烯在液-液界面的研究概况 5

1.6.1 GO二维界面自组装 6

1.6.2 GO三维界面自组装 6

1.6.3 BF自组装 6

1.7分子模拟概况 6

1.7.1分子力场 7

1.7.2分子动力学模拟 7

第二章 模拟方法及细节 9

2.1模型 9

2.2模拟方法 10

第三章 结果与讨论 12

3.1密度分布曲线的计算 12

3.2 PMF计算 12

3.3无约束分子动力学模拟计算 14

3.4接触角计算 16

第四章 结论与展望 18

4.1结论 18

4.2展望 18

参考文献 19

致谢 21

第一章 绪论

1.1引言

石墨烯是由单层碳原子形成的碳材料(如图1-1), Novoselov^[1]等人获得了单层石墨烯，发现其独特的电子特征, 虽然理论研究认为二维结构是无法在绝对零度之外以稳定的方式存在，但是单层的石墨烯却可以在实验中被制备。石墨烯有大的比表面积和超强的导电性等优点，然而，其分子间具有很强的相互作用，而且有易团聚和疏水性等特点，这些方面都限制了石墨烯的应用，为了使石墨烯的特性发生改变，经过研究成功制备了各种功能化石墨烯，最常见的就是氧化石墨烯(GO)。

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