Surface tension effect on the mechanical properties of nanomaterials measured by atomic force microscopy

TLDR

The study examines how reduced size affects the elastic properties of silver, lead nanowires, and polypyrrole nanotubes (30–250 nm). Resonant‑contact AFM was employed to measure the apparent elastic modulus of these nanomaterials. Nanomaterials with smaller diameters exhibited significantly higher apparent elastic modulus, comparable to their macroscopic values, and this increase was attributed to surface tension effects, which can be quantified from the AFM measurements.

Abstract

The effect of reduced size on the elastic properties measured on silver and lead nanowires and on polypyrrole nanotubes with an outer diameter ranging between 30 and 250 nm is presented and discussed. Resonant-contact atomic force microscopy (AFM) is used to measure their apparent elastic modulus. The measured modulus of the nanomaterials with smaller diameters is significantly higher than that of the larger ones. The latter is comparable to the macroscopic modulus of the materials. The increase of the apparent elastic modulus for the smaller diameters is attributed to surface tension effects. The surface tension of the probed material may be experimentally determined from these AFM measurements.