College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China.
State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China.
Molecules. 2019 Mar 20;24(6):1103. doi: 10.3390/molecules24061103.
In this paper, the thermal properties of graphene oxide (GO) with vacancy defects were studied using a non-equilibrium molecular dynamics method. The results showed that the thermal conductivity of GO increases with the model length. A linear relationship of the inverse length and inverse thermal conductivity was observed. The thermal conductivity of GO decreased monotonically with an increase in the degree of oxidation. When the degree of oxidation was 10%, the thermal conductivity of GO decreased by ~90% and this was almost independent of chiral direction. The effect of vacancy defect on the thermal conductivity of GO was also considered. The size effect of thermal conductivity gradually decreases with increasing defect concentration. When the vacancy defect ratio was beyond 2%, the thermal conductivity did not show significant change with the degree of oxidation. The effect of vacancy defect on thermal conductivity is greater than that of oxide group concentration. Our results can provide effective guidance for the designed GO microstructures in thermal management and thermoelectric applications.
本文采用非平衡分子动力学方法研究了具有空位缺陷的氧化石墨烯(GO)的热性能。结果表明,GO 的热导率随模型长度的增加而增加。观察到长度倒数和热导率倒数的线性关系。GO 的热导率随氧化程度的增加单调下降。当氧化程度为 10%时,GO 的热导率下降了约 90%,且几乎与手性方向无关。还考虑了空位缺陷对 GO 热导率的影响。热导率的尺寸效应随缺陷浓度的增加逐渐减小。当空位缺陷比超过 2%时,热导率随氧化程度的变化不再明显。空位缺陷对热导率的影响大于氧化基团浓度的影响。我们的研究结果可为热管理和热电应用中设计的 GO 微结构提供有效的指导。