Nikkhah S Javan, Moghbeli M R, Hashemianzadeh S M
School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran 16846-13114, Iran.
J Mol Model. 2015 May;21(5):121. doi: 10.1007/s00894-015-2665-6. Epub 2015 Apr 19.
In this study, interfacial adhesion between functionalized polyethylene (PE) surfaces and graphene were examined using molecular simulation. Various functional groups including amino, carboxy, hydroxy, cyano, isocyanato, oxo, and ethylamino were used to cover the PE surface with surface densities of 0.48, 1.30, and 4.84 groups per nm(2). The interfacial adhesion between the modified PE surfaces and the graphene was quantified via calculation of work of separation (Wsep), the amount of the required work to separate two surfaces without occurring any relaxation and diffusion phenomena. Insertion of the functional groups on the PE surface decreased the amount of Wsep, except for the oxo, amino, and higher densities of the carboxy groups. Increasing the surface group density enhanced the adhesion due to decreasing the surface atomic roughness and increasing the atomic density at the interface. In addition, the effect of surface group rearrangement was investigated via calculation of the work of adhesion (Wadh) while sufficient time had been devoted to relax the interface. The surface reorganization during the relaxation process significantly enhanced adhesion due to eliminating the surface roughness and increasing the surface atomic density.
在本研究中，使用分子模拟研究了功能化聚乙烯（PE）表面与石墨烯之间的界面粘附力。使用包括氨基、羧基、羟基、氰基、异氰酸酯基、氧代和乙氨基在内的各种官能团以每纳米² 0.48、1.30和4.84个基团的表面密度覆盖PE表面。通过计算分离功（Wsep）来量化改性PE表面与石墨烯之间的界面粘附力，Wsep是指在不发生任何松弛和扩散现象的情况下分离两个表面所需的功的量。在PE表面引入官能团会降低Wsep的值，但氧代、氨基和较高密度的羧基除外。增加表面基团密度可增强粘附力，这是由于表面原子粗糙度降低以及界面处原子密度增加所致。此外，在给予足够时间使界面松弛的情况下，通过计算粘附功（Wadh）研究了表面基团重排的影响。松弛过程中的表面重组通过消除表面粗糙度和增加表面原子密度显著增强了粘附力。
