Angstrom-Scale Fluidic Channels: Molecular Transport


Event details

Date 17.03.2023
Hour 14:0015:00
Speaker Prof. Radha Boya, University of Manchester (UK)
Location Online
Category Conferences - Seminars
Event Language English
Understanding molecular transport in nano/angstrom scale channels has practical relevance in applications such as membrane desalination, blue energy, supercapacitors and batteries, as well as in understanding ionic flow through biological channels. Synthetic Å-channels are now a reality with the emergence of several cutting-edge bottom-up and top-down fabrication methods. In particular, the use of atomically thin 2D-materials and nanotubes as components to build fluidic conduits has pushed the limits of fabrication to the Å-scale. In this talk, I will discuss about angstrom (Å)-scale capillaries which are rectangular slit-shaped channels and are created by extracting one-atomic layer out of a crystal [1]. The Å-capillary is an antipode of graphene and can be dubbed as “2D-nothing”. What is intriguing here is, the dimensions of the thinnest channels being comparable to the size of a water molecule.
The Å-capillaries have helped probe several intriguing molecular-scale phenomena experimentally, including: water flow under extreme atomic-scale confinement [1] complete steric exclusion of ions [3,5], specular reflection and quantum effects in gas reflections off a surface [2,7], voltage gating of ion flows [4] translocation of DNA [6]. I will present ionic flows induced by stimuli (electric, pressure, concentration gradient) and discuss the importance of ionic parameters that are often overlooked in the selectivity between ions [7], along with ionic memory effects [8].

I acknowledge the contributions to this work from my collaborators and colleagues A.K. Geim, A. Keerthi, A. Ismail, K. Gopinadhan, A. Esfandiar, S. Goutham, Y. You, S. J Haigh, R.Sajja, A.Bhardwaj, G.H-Nam from University of Manchester; L. Bocquet, P. Robin, T. Emmerich, T. Mouterde, A. Poggioli, A. Siria, from Micromégas team, ENS Paris; my theory collaborators F.C. Wang, M. Neek-Amal.

[1] B. Radha et al., Molecular transport through capillaries made with atomic-scale precision. Nature 538, 222 (2016).
[2] A. Keerthi et al., Ballistic molecular transport through two-dimensional channels, Nature (2018), 558, 420.
[3] A. Esfandiar et al., Size effect in ion transport through angstrom-scale slits. Science 358, 511 (2017).
[4] T. Mouterde et al., Molecular streaming and voltage gated response in Angstrom scale channels. Nature 567, 87 (2019).
[5] K. Gopinadhan et al., Complete ion exclusion and proton transport through monolayer water. Science 363, 145 (2019).
[6] Y. You, A.Ismail et al., Angstrofluidics: walking to the limit. Annual Reviews for Materials Research 52, 189, (2022).
[7] S. Goutham et al., Beyond steric selectivity of ions using angstrom-scale capillaries, Nature Nanotechnology in press (2023); arXiv:2212.09584.
[8] P. Robin et al., Long-term memory and synapse-like dynamics of ionic carriers in two-dimensional nanofluidic channels, Science (2023) in press, arXiv:2205.07653.

Prof. Radha Boya FRSC is a Professor, Royal Society University Research fellow and Kathleen Ollerenshaw fellow at the University of Manchester. After completing her PhD in India and a brief post-doctoral stint in the United States, she has secured a series of highly prestigious international research fellowships that have enabled her to rapidly build her research profile in the United Kingdom. She has published 60 research papers including several of these in Nature and Science journals. Radha was awarded an ERC starting grant, Analytical Chemistry Young Innovator award, Philip Leverhulme Prize in Physics, RSC Marlow award, UNESCO-L’Oréal International Rising Talent, L’Oréal UK & Ireland women in science fellow, and was recognized as an inventor of MIT Technology Review's global "Innovators under 35" list.

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