Small nanoparticles, surface geometry and contact forces

Abstract

In this molecular dynamics study, we examine the local surface geometric effects of the normal impact force between two approximately spherical nanoparticles that collide in a vacuum. Three types of surface geometries—(i) crystal facets, (ii) sharp edges, and (iii) amorphous surfaces of small nanoparticles with radii R <10 nm—are considered. The impact forces are compared with their macroscopic counterparts described by nonlinear contact forces based on Hertz contact mechanics. In our simulations, edge and amorphous surface contacts with weak surface energy reveal that the average impact forces are in excellent agreement with the Hertz contact force. On the other hand, facet collisions show a linearly increasing force with increasing compression. Our results suggest that the nearly spherical nanoparticles are likely to enable some nonlinear dynamic phenomena, such as breathers and solitary waves observed in granular materials, both originating from the nonlinear contact force.

Document Details

Document Type
Pub Defense Publication
Publication Date
Mar 01, 2018
Source ID
10.1098/rspa.2017.0723

Entities

People

  • Michael E. Benson
  • Surajit Sen
  • Yoichi Takato

Organizations

  • Army Research Office
  • Okinawa Institute of Science and Technology
  • University at Buffalo

Tags

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Nanocomposite Materials Science
  • Thin Film Deposition Science.

Technology Areas

  • Biotechnology