Abstract:

The pressure-driven flow properties of the fullerene-water nanofluids confined in graphene nanochannels are investigated by using classical molecular dynamics simulations. The influences of the driving force, the volume fraction, and the electrical field intensity on the motion behaviors and the boundary slip are explored with considering the dynamics and the accumulation of the fullerene within the nanofluids. The results show that the relatively large driving force can weaken the accumulation of the fullerenes. The increase in the volume fraction of the fullerene in nanofluids can enhance the shear viscosity, induce the accumulation of the fullerenes,and it can also increase the boundary slip velocity of the nanofluids in graphene channels. As the electric field intensity of the graphene channel increases, the boundary slip of fullerene nanofluids first increases to a maximum and then decreases gradually, attributed to a cooperative phenomenon of the three key factors which are the variation of the interfacial coupling strength, the formation of the hydrophobic water monolayer, and the motion of the fullerene clusters. The findings may be helpful to the design and fabrication of the low dimensional carbon materials-based nano-apparatus.

Key words: graphene, nanoparticles, nanofluid, agglomeration, computer simulation

摘要：

采用分子动力学方法探索了水-富勒烯纳米流体在石墨烯纳米孔隙中Poiseuille流动特性。从富勒烯的微观运动及团簇行为的角度出发，考虑了驱动作用力、富勒烯体积分数和电场强度对纳米流体流动特性的影响机理。发现较大的压力驱动作用可以弱化纳米流体中富勒烯分子的团簇效应；富勒烯体积分数的增加会提高纳米流体剪切黏性，并促进富勒烯分子发生团簇，还会导致纳米流体边界滑移速度的增加；石墨烯壁面上的电场强度的增大，会使富勒烯纳米流体的边界滑移速度先减小后增大，阐明了电场强度对纳米流体边界滑移的影响是石墨烯-流体界面作用强度变化、疏水单分子层的形成和富勒烯团簇的运动行为三者协同作用的结果。

关键词: 石墨烯, 纳米粒子, 纳米流体, 团聚, 计算机模拟