Loading…

Equipartition of Energy Defines the Size–Thickness Relationship in Liquid-Exfoliated Nanosheets

Liquid phase exfoliation is a commonly used method to produce 2D nanosheets from a range of layered crystals. However, such nanosheets display broad size and thickness distributions and correlations between area and thickness, issues that limit nanosheet application potential. To understand the fact...

Full description

Saved in:
Bibliographic Details
Published in:ACS nano 2019-06, Vol.13 (6), p.7050-7061
Main Authors: Backes, Claudia, Campi, Davide, Szydlowska, Beata M, Synnatschke, Kevin, Ojala, Ezgi, Rashvand, Farnia, Harvey, Andrew, Griffin, Aideen, Sofer, Zdenek, Marzari, Nicola, Coleman, Jonathan N, O’Regan, David D
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Liquid phase exfoliation is a commonly used method to produce 2D nanosheets from a range of layered crystals. However, such nanosheets display broad size and thickness distributions and correlations between area and thickness, issues that limit nanosheet application potential. To understand the factors controlling the exfoliation process, we have liquid-exfoliated 11 different layered materials, size-selecting each into fractions before using AFM to measure the nanosheet length, width, and thickness distributions for each fraction. The resultant data show a clear power-law scaling of nanosheet area with thickness for each material. We have developed a simple nonequilibrium thermodynamics-based model predicting that the power-law prefactor is proportional to both the ratios of in-plane-tearing/out-of-plane-peeling energies and in-plane/out-of-plane moduli. By comparing the experimental data with the modulus ratio calculated from first-principles, we find close agreement between experiment and theory. This supports our hypothesis that energy equipartition holds between nanosheet tearing and peeling during sonication-assisted exfoliation.
ISSN:1936-0851
1936-086X
DOI:10.1021/acsnano.9b02234