PHENIX Seminar : Alice Thorneywork 14th April 2023 11am 32-42 101

Published on : 14/04/2023

Understanding molecular fluctuations and transport with multiscale experimental models

Prof. Alice Thorneywork,

Physical and Theoretical Chemistry Laboratory, University of Oxford

The effective transport of particles across membranes is essential to the functioning of many systems, from synthetic filters and sensing technologies to biological pores and channels. In nature, this often involves channels or pores which are optimized for transport of a certain species by their size, shape or the inclusion of specific binding sites. Replicating such highly efficient and selective transport in synthetic systems, however, represents an ongoing challenge, in part 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 not only collective, many particle effects, but also the single particle behaviours and fluctuations that give rise to them.

In this talk, I will discuss some recent examples of how we are using experimental soft matter models to elucidate details of transport processes at the nanoscale and mesoscale. At the nanoscale, we probe the transport of ions through nanopores by measurement of an ionic current. We have recently explored the effect on these currents of passive adsorption of polymers to the pore surface and, excitingly, how this can be linked to details of the polymer adsorption potential [1]. Alongside this, we are developing colloidal models to explore similar aspects of transport and fluctuations in directly observable mesoscale systems. Here, we have previously demonstrated that single particle colloidal dynamics can be directly linked to transport through biological pores [2], and I will share details of our current efforts to now extend these ideas to many-body hard sphere systems [3].

[1] S. F. Knowles, A. L. Thorneywork et al., Phys. Rev. Lett, 127, 137801, (2021)

[2] A. L. Thorneywork et al., Sci. Adv., 6 (18), eaaz4642, (2020)

[3] S. F. Knowles, A. L. Thorneywork et al., J. Phys.: Condens. Matter, 34, 344001, (2022)