Thermal Gradients on Graphene to Drive Nanoflake Motion
Thermal Gradients on Graphene to Drive Nanoflake Motion
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DOI：
10.1021/ct400963d
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发表时间：
2014-02-01
影响因子：
5.5
通讯作者：
Wang, Xianqiao
中科院分区：
文献类型：
--
作者：
Becton, Matthew;Wang, Xianqiao
热泳技术是一种新兴的纳米粒子操控技术。具有良好导热性和低表面摩擦的材料，如石墨烯，最适合用作固体运输或操纵的平台。本文采用非平衡态分子动力学模拟方法，探讨了利用大尺寸石墨烯衬底上的热梯度来控制小尺寸石墨烯纳米片在衬底上运动的可行性，系统地研究了石墨烯石墨烯输运的基本驱动机制，以及温度梯度和石墨烯几何形状等重要参数对石墨烯输运的定量影响。纳米片的运动。模拟结果表明，温度梯度在石墨烯表面的纳米片的运动演化中起着关键作用。此外，纳米片的几何形状在纳米片的运动中呈现出一个有趣的特征，这表明圆形纳米片比具有相同面积的其他形状移动得更慢，但旋转得更快。结果表明，边缘效应可以稳定热致发光驱动粒子的角运动。利用操纵分子动力学方法定量地描述了有效初始驱动力与温度梯度之间的关系。这些发现将提供基本的见解纳米器件在固体表面上的运动，由于热泳，并将提供新的观点操纵纳米粒子在固体表面上的技术，如细胞分离，水净化和化学提取。
Thermophoresis has been emerging as a novel technique for manipulating nanoscale particles. Materials with good thermal conductivity and low surface friction, such as graphene, are best suited to serve as a platform for solid solid transportations or manipulations. Here we employ nonequilibrium molecular dynamics simulations to explore the feasibility of utilizing a thermal gradient on a large graphene substrate to control the motion of a small graphene nanoflake on it. Attempts to systematically investigate the mechanism of graphene graphene transportation have centered on the fundamental driving mechanism of the motion and the quantitative effect of significant parameters such as temperature gradient and geometry of graphene on the motion of the nanoflake. Simulation results have demonstrated that temperature gradient plays the pivotal role in the evolution of the motion of the nanoflake on the graphene surface. Also, the geometry of nanoflakes has presented an intriguing signature on the motion of the nanoflake, which shows nanoflakes with a circular shape move slower but rotate faster than other shapes with the identical area. It reveals that edge effects can stabilize the angular motion of thermophoretically driven particles. An interesting relation between the effective initial driving force and temperature gradient has been quantitatively captured by employing the steered molecular dynamics. These findings will provide fundamental insights into the motion of nanodevices on a solid surface due to thermophoresis, and will offer the novel view for manipulating nanoscale particles on a solid surface in techniques such as cell separation, water purification, and chemical extraction.