Multiscale transitional flow in anisotropic nanoparticle suspensions revealed by time-resolved X-ray scatter microscopy
Journal article, 2026
Complex fluids transition from laminar to transitional flow above a critical control parameter, in a similar manner to their Newtonian counterparts. In a continuum mechanics sense, fluid elements follow the ensuing complex trajectories, which gives rise to secondary flows in terms of macroscopic vortices. However, it is not known whether their trajectories exhibit the same spatiotemporal behaviour as the macroscopic flow field if idealized fluid elements are replaced with actual anisotropic nanoparticles. Here, to address this fundamental question, we develop a multiscale method that combines small-angle X-ray scatter microscopy with polarized light imaging, thereby bridging seven orders of magnitude in length scales. We demonstrate proof of principle for Taylor–Couette flow—a classical transitional flow problem—of platelet-like graphene oxide nanoparticle and rod-like cellulose nanocrystal suspensions. The analysis shows markedly different multiscale dynamics underlying flow stability: whereas the platelet-like particles follow the macroscopic dynamics of the secondary flows, as expected for high rotational Péclet numbers, the rod-like particles exhibit characteristic high-frequency orientational motion at moderate rotational Péclet numbers that correlates with the turnover frequency of the vortex instabilities.
Author
Kesavan Sekar
Chalmers, Industrial and Materials Science, Engineering Materials
Wallenberg Wood Science Center (WWSC)
Viney Ghai
theion GmbH
Chalmers, Industrial and Materials Science, Engineering Materials
Reza Ghanbari
NKT Technology Consulting AB
MAX IV Laboratory
Marko Bek
Wallenberg Wood Science Center (WWSC)
Chalmers, Industrial and Materials Science, Engineering Materials
Lund Institute of Advanced Neutron and X-ray Science (LINXS)
Marianne Liebi
Chalmers, Physics, Materials Physics
Paul Scherrer Institut
Swiss Federal Institute of Technology in Lausanne (EPFL)
Aleksandar Matic
Chalmers, Physics, Materials Physics
Wallenberg Wood Science Center (WWSC)
Ann Terry
Lund Institute of Advanced Neutron and X-ray Science (LINXS)
MAX IV Laboratory
Kim Nygård
MAX IV Laboratory
Lund Institute of Advanced Neutron and X-ray Science (LINXS)
Roland Kádár
MAX IV Laboratory
Computational Mechanics and Materials Engineering
Lund Institute of Advanced Neutron and X-ray Science (LINXS)
Wallenberg Wood Science Center (WWSC)
Nature Physics
1745-2473 (ISSN) 17452481 (eISSN)
Vol. In Press2D material-based technology for industrial applications (2D-TECH) Phase 2
VINNOVA (2024-03852), 2024-11-01 -- 2029-12-31.
Mölnlycke healthcare (2024-03852), 2025-01-01 -- 2029-12-31.
Subject Categories (SSIF 2025)
Materials Chemistry
Fluid Mechanics
Physical Chemistry
Areas of Advance
Nanoscience and Nanotechnology
Production
Materials Science
DOI
10.1038/s41567-026-03467-1
Related datasets
Dataset [dataset]
DOI: 10.6084/m9.figshare.30961856