One atom thin Capillaries: Confined Water, Ion and Gas flows

One atom thin Capillaries: Confined Water, Ion and Gas flows
Radha Boya, University of Manchester
Radha Boya
Date and time: Thu, Apr 01, 2021 - 11:30am
Category: Condensed Matter Seminar
Abstract:

It has been an aspiring goal to controllably fabricate nanopores and capillaries with dimensions approaching the size of small ions and water molecules. But surface roughness makes it challenging to produce capillaries with precisely controlled dimensions at this spatial scale. We have developed a method for fabrication of one atom thin, smooth angstrom (Å) scale capillaries through van der Waals assembly of two-dimensional (2D)-materials [1-5]. These capillaries can be envisaged as if individual atomic planes are removed from a bulk layered crystal leaving behind flat voids of a chosen height. 

A core strand of the work that I will present is the development of Angstrom-capillaries as a platform to probe intriguing molecular-scale phenomena experimentally, including: water flow under extreme atomic-scale confinement [5], complete steric exclusion of ions [3,5], voltage gating of ion flows [4] translocation of DNA [6], and specular reflection and quantum effects in gas reflections off a surface [2]. I will discuss and compare these gas flows to that in atomic-scale apertures, created from missing tungsten (W) sites in freestanding (WS2) monolayers, which show fast helium flow [7].

References: [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, 558, 420 (2018). [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] W. Yang et al., Advanced Materials 2007682, (2021). [7] J. Thiruraman et al., Gas flows through atomic-scale apertures, Science Advances 6, eabc7927, (2020).

A brief Bio: Prof. Radha Boya FRSC is a Chair (hon.) in Nanoscience, Royal Society University Research and Kathleen Ollerenshaw fellow at the University of Manchester (UoM). She completing her PhD in India and worked as a post-doctoctoral fellow in Northwestern University, United States. She has secured a series of highly prestigious international research fellowships, Mari-Curie fellowship, Kathleen Ollerenshaw fellowship, Royal society university research fellowship that have enabled her to rapidly build her research profile in the United Kingdom. Radha has 50 peer-reviewed publications, written two book chapters and has three patents.  She was awarded  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.