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Join the Department of Physics for a seminar entitled ‘Transport and nanoconfinement effects inside van der Waals nanocapillaries’ with Dr Qian Yang, Royal Society University Research Fellow at the University of Manchester. 

Abstract

Isolated 2D crystals can be assembled into designer structures layer-by-atomic-layer in a precisely chosen sequence using van der Waals (vdW) technology. Using this method, we have demonstrated the creation of two-dimensional capillaries (Figure 1) by assembling 2D crystals [1]. This technology offers the smallest possible empty spaces that can vary from just a few angstroms in height up to tens of nanometers on demand. On this basis, the transport of water and ionic species inside capillaries were investigated, offering better understanding of molecule-capillary interactions under confinement. We report quantized water filling, where water enters the nanocapillaries layer-by-layer, directly revealing its discrete molecular nature under strong confinement [2]. We also found that the capillary wall rigidity determines the filling dynamics – the filling transition from layer-by-layer to an abrupt manner with increasing wall rigidity. Recently, a more efficient method to fabricate these nanocapillaries was developed, which broadens their adoption in the community and opens research opportunities in nanofluidics, membrane science and chemistry [3].

Beyond artificial nanocapillaries, we also explored nanoconfined water in naturally structured 2D systems, including gypsum crystals [4] and the graphene-water interface [5]. Our results resolve the molecular-scale structure, dynamics, and electrochemical environment of confined water and ions, and provide actionable principles for separation science, sensing technologies, and the design of next-generation nanofluidic systems.

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Biography

Dr Qian Yang is a Senior Research Fellow, Royal Society University Research Fellow at the Department of Physics and Astronomy, the University of Manchester, UK. She received her PhD in Material Science and Engineering in 2018. Her research focused on the mass transport in two-dimensional (2D) nanocapillaries, confinement effects on molecular behaviours, nanofluidics and other electrokinetic phenomena. She is currently also the Academic Theme Lead for Graphene Engineering and Innovation Centre (GEIC), supporting industrial translation of graphene and 2D materials related products. She is the recipient of the Leverhulme Early Career Fellowship (2019), Dame Kathleen Ollerenshaw Fellowship (2021), Royal Society University Research Fellowship (2022) and the European Research Council Starting Grant (2022).