Mechanical Reshaping of Inorganic Nanostructures with Weak Nanoscale Forces

Nano Lett. 2021 Jan 13;21(1):130-135. doi: 10.1021/acs.nanolett.0c03383. Epub 2020 Dec 10.

Abstract

Inorganic nanomaterials are often depicted as rigid structures whose shape is permanent. However, forces that are ordinarily considered weak can exert sufficient stress at the nanoscale to drive mechanical deformation. Here, we leverage van der Waals (VdW) interactions to mechanically reshape inorganic nanostructures from planar to curvilinear. Modified plate deformation theory shows that high-aspect-ratio two-dimensional particles can be plastically deformed via VdW forces. Informed by this finding, silver nanoplates were deformed over spherical iron oxide template particles, resulting in distinctive bend contour patterns in bright-field (BF) transmission electron microscopy (TEM) images. High-resolution TEM images of deformed areas reveal the presence of highly strained bonds in the material. Finally, we show that the distance between two nearby template particles allows for the engineering of several distinct curvilinear morphologies. This work challenges the traditional view of nanoparticles as static objects and introduces methods for postsynthetic mechanical shape control.

Keywords: curvilinear; deformation; nanomechanics; nanoplate; nanostructure; postsynthetic modification.