Abstract

Sensitively controlling transport across membranes is central to many technologies, from biomedical sensors and desalination devices to the emerging field of iontronics. Rational design of porous materials with specific transport properties represents an ongoing challenge, however, partly because unambiguously elucidating transport mechanisms in molecular level experiments is very difficult. Valuable insights can thus be provided by experimental models that display analogous physical behaviour but are experimentally much more accessible. Importantly, such systems allow us to explore both collective, many particle effects, and the single particle behaviours and fluctuations that give rise to them.

In this talk, I will discuss our work using experimental soft matter models at the mesoscale to elucidate details of transport processes at the nanoscale, and in particular to understand the nature of fluctuations in these systems. I will first share some recent results taking a fresh look at fluctuations in equilibrium colloidal monolayers. Here, we have combined experiment, simulation and theory to explore how simply counting colloids can reveal details of self and collective dynamics, uncovering a surprising hydrodynamic enhancement of collective diffusion and a new length scale linked to hyperuniform-like structure [1]. I will then discuss ongoing work to extend this understanding to driven systems, with the long-term goal of elucidating characteristic fluctuations in our synthetic nanopore systems.

[1] E. K. R. Mackay, B. Sprinkle, S. Marbach, A. L. Thorneywork, arXiv:2311.00647 (2023) [2] S. F. Knowles, et al., J. Phys.: Condens. Matter, 34, 344001 (2022)