Molecular dynamics simulation of the effect of oxygen-containing functional groups on the thermal conductivity of reduced graphene oxide
Molecular dynamics simulation of the effect of oxygen-containing functional groups on the thermal conductivity of reduced graphene oxide
复制标题
含氧官能团对还原氧化石墨烯导热系数影响的分子动力学模拟
DOI：
10.1016/j.commatsci.2018.02.037
复制
发表时间：
2018-06-01
影响因子：
3.3
通讯作者：
Du, Xiaoze
中科院分区：
文献类型：
--
作者：
Sun, Yingying;Chen, Lin;Du, Xiaoze
建立了不同层数和模拟尺寸的还原氧化石墨烯（RGO）模型，并进行了分子动力学模拟，研究了含氧官能团对RGO热导率的影响。结果表明：单层RGO（MRGO）和双层RGO（BRGO）的TC均随模拟长度的增加而增加;在相同模拟尺寸下，BRGO的TC始终低于MRGO。随着官能团含量的增加，MRGO和BRGO的TC均先增加后下降。对于MRGO，最佳含量在2%左右。当官能团含量低于2%时，MRGO的声子共振频率保持不变，当官能团含量高于2%时，MRGO的声子共振频率向低频移动，证实了官能团和波纹结构对声子散射的影响.对于BRGO，最佳含量发生在约1%，这低于MRGO，因为BRGO的层间距离随着官能团含量的增加而线性增加。此外，BRGO的相互作用能和层间热阻的变化趋势与BRGO的TC变化趋势一致。(C)2018 Elsevier B. V.版权所有。
Models of reduced graphene oxide (RGO) with different numbers of layers and simulation sizes were established and molecular dynamics simulations were performed to study the influence of oxygen-containing functional groups on the thermal conductivity (TC) of RGO. The results show that the TCs of both monolayer RGO (MRGO) and bilayer RGO (BRGO) increase with the increasing simulation length; under the same simulation size, the TC of BRGO is always lower than that of the MRGO. With the increasing content of functional groups, TCs of both MRGO and BRGO increase firstly and then decline. For MRGO, the optimum content occurs at about 2%. The phonon resonant frequency of MRGO with content of functional groups lower than 2% remains constant, and shifts to a lower frequency when the content of functional groups is higher than 2%; this confirms the effects of functional groups and wrinkling structure with ripples on the phonon scattering. For BRGO, the optimum content occurs at about 1%, which is lower than that for MRGO, since the interlayer distance of BRGO increases linearly with the increasing content of functional groups. Moreover, the changing trends of interaction energy and interlayer thermal resistance of BRGO are consistent with the TC change of BRGO. (C) 2018 Elsevier B.V. All rights reserved.