Mesoscale simulation of aggregation of imogolite nanotubes from potential of mean force interactions

Abstract

The aggregation of colloidal clay mineral particles plays an important role in controlling the mechanical and transport properties of soils. Interactions and aggregation of plate-like montmorillonite particles were previously studied with the help of Molecular Dynamics (MD) simulation. This paper investigates the aggregation of cylindrical imogolite-like phyllosilicate nanotubes. Nano-scale MD simulations are carried out to find the potential of mean force between two nanotubes. This PMF is then used in a mesoscale simulation that represents interactions between elemental nanotubes through coarse-graining. We investigate the distribution of water molecules around the curved surfaces, and the effects of the surface charge density and tube length on aggregation. Shorter nanotubes were found to form larger stacks.

GRAPHICAL ABSTRACT

Keywords:

• Molecular simulation
• coarse-grained
• aggregation
• imogolite

Acknowledgments

This work used the Extreme Science and Engineering Discovery Environment (XSEDE) [34] Stampede2 at Texas Advanced Computing Center (TACC) through allocations TG-MSS170021 and TG-MSS180023, which are supported by National Science Foundation grant number ACI-1548562. Roland Pellenq and Aikaterini Ioannidou wish to thank CNRS and Aix-Marseilles Université foundation for their support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors acknowledge the funding support from the US National Science Foundation (NSF) [ACI-1548562] under the grant no. 1702689 ‘Collaborative Research: Multi-scale Modelling and Measurement of Clay Aggregate Behaviour’.