Nemati Alireza, Nejat Pishkenari Hossein, Meghdari Ali, Ge Shuzhi Sam
Institute for Future (IFF), Qingdao University, Qingdao 266071, China.
Phys Chem Chem Phys. 2020 Dec 7;22(46):26887-26900. doi: 10.1039/d0cp04960c.
Molecular machines, such as nanocars, have shown promising potential for various tasks, including manipulation at the nanoscale. In this paper, we examined the influence of temperature gradients on nanocar and nanotruck motion as well as C60 - as their wheel - on a flat gold surface under various conditions. We also compared the accuracy and computational cost of two different approaches for generating the temperature gradient. The results show that severe vibrations and frequent impacts of gold atoms at high temperatures increase the average distance of C60 from the substrate, reducing its binding energy. Moreover, the temperature field drives C60 to move along the temperature variation; still, the diffusive motion of C60 remained unchanged in the direction perpendicular to the temperature gradient. Increasing the magnitude of the temperature gradient speeds up its motion parallel to the gradient, while raising the average temperature of the substrate increases the diffusion coefficient in all directions. The temperature field influences the nanocar motion in the same manner as C60. However, the nanocars have a substantially shorter motion range compared to C60. The relatively larger, heavier, and more flexible chassis of the nanocar makes it more sluggish than the nanotruck. In general, the motion of large and heavy surface rolling molecules is less affected by the temperature field compared to small and light molecules. The results of the study show that concentrated heat sources can be employed to push surface rolling molecules or break down their large clusters. We can exploit a temperature field as a driving force to push nanocars in a desired direction on prebuilt pathways.
分子机器，如纳米车，在包括纳米尺度操作在内的各种任务中展现出了广阔的潜力。在本文中，我们研究了温度梯度在不同条件下对纳米车和纳米卡车运动以及作为其车轮的C60在平坦金表面上的影响。我们还比较了两种产生温度梯度的不同方法的准确性和计算成本。结果表明，高温下金原子的剧烈振动和频繁撞击增加了C60与基底的平均距离，降低了其结合能。此外，温度场驱动C60沿着温度变化方向移动；不过，C60在垂直于温度梯度方向上的扩散运动保持不变。增大温度梯度的幅度会加快其平行于梯度方向的运动，而提高基底的平均温度会增加各个方向上的扩散系数。温度场对纳米车运动的影响与对C60的影响方式相同。然而，与C60相比，纳米车的运动范围要短得多。纳米车相对更大、更重且更灵活的底盘使其比纳米卡车更迟缓。一般来说，与小而轻的分子相比，大而重的表面滚动分子的运动受温度场的影响较小。研究结果表明，可以利用集中热源来推动表面滚动分子或分解它们的大簇。我们可以利用温度场作为驱动力，在预先构建的路径上沿所需方向推动纳米车。
