Wan Jiawei, Zhang Qiubo, Liang Jiayun, Bustillo Karen C, Al Balushi Zakaria Y, Asta Mark, Zheng Haimei
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States.
Nano Lett. 2023 Nov 22;23(22):10132-10139. doi: 10.1021/acs.nanolett.3c02291. Epub 2023 Nov 1.
Nanomotors in solution have many potential applications. However, it has been a significant challenge to realize the directional motion of nanomotors. Here, we report cadmium chloride tetrahydrate (CdCl·4HO) nanomotors with remarkable directional movement under electron beam irradiation. Using in situ liquid phase transmission electron microscopy, we show that the CdCl·4HO nanoparticle with asymmetric surface facets moves through the liquid with the flat end in the direction of motion. As the nanomotor morphology changes, the speed of movement also changes. Finite element simulation of the electric field and fluid velocity distribution around the nanomotor assists the understanding of ionic self-diffusiophoresis as a driving force for the nanomotor movement; the nanomotor generates its own local ion concentration gradient due to different chemical reactivities on different facets.
溶液中的纳米马达有许多潜在应用。然而，实现纳米马达的定向运动一直是一项重大挑战。在此，我们报道了四水合氯化镉（CdCl·4H₂O）纳米马达在电子束照射下具有显著的定向运动。通过原位液相透射电子显微镜，我们表明具有不对称表面晶面的CdCl·4H₂O纳米颗粒以平面端朝着运动方向在液体中移动。随着纳米马达形态的变化，运动速度也会改变。对纳米马达周围电场和流体速度分布的有限元模拟有助于理解离子自扩散电泳作为纳米马达运动的驱动力；由于不同晶面上的化学反应性不同，纳米马达产生自身的局部离子浓度梯度。
