Authors: Shenghui Chen Qiang Lv Zhikun Wang Chunling Li Charles U Pittman Steven R Gwaltney Shuangqing Sun Songqing Hu
Publish Date: 2017/01/23
Volume: 52, Issue: 10, Pages: 5672-5685
Abstract
Molecular dynamics simulations are used to investigate the effect of graphene dispersion on the equilibrium structure and deformation of graphene/eicosane composites Two graphene sheets with four different interlayer distances are incorporated respectively into a eicosane matrix to form graphene/eicosane composites representing different graphene dispersions With greater graphene dispersion the “adsorption solidification” of the eicosane increases where eicosane molecular lamination orientation and extension become more uniform and stronger In addition eicosane molecular motion is inhibited more in the direction perpendicular to graphene surfaces When these graphene/eicosane composites are deformed the free volume initially increases slowly due to small scattered voids After reaching the yield strains the free volume rises sharply as the structures of composites are damaged and small voids merge into large voids The damage always occurs in the region of the composite with the weakest “adsorption solidification” Since this effect is stronger when the graphene sheets are more dispersed more complete dispersion results in higher composite yield stresses Lessons from these simulations may provide some insights into graphene/polyethylene composites where suitable models would require very long equilibration timesThis work is supported by the National Natural Science Foundation of China 51501226 and 51201183 and the Fundamental Research Funds for the Central Universities 15CX08009A 15CX02066A and 14CX02221A Shenghui Chen wishes to thank Dr Thomas E Lacy Mississippi State University for the helpful discussions with him
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