Terahertz-Light Induced Structural Transition and Superpermeation of Confined Monolayer Water
Zhi Zhu, Chen Chen, Chao Chang, Bo Song
Abstract
The confined monolayer water between atomic-gapped graphene-based membranes has broad and promising applications in seawater desalination and water purification, which benefits from the fast transport of water and subsequent low energy cost. However, it is still unclear whether there are approaches to further improve the transport of water across membranes. Herein, based on molecular dynamics simulations, we propose that a light stimulus with the frequency of 31.5 ± 1.0 THz can nonthermally enhance the permeation of confined monolayer water across a graphene-based membrane by 37-fold, followed by a transition to the super permeation state of confined water. The underlying mechanism is disclosed to involve a THz light-induced structural phase transition of the monolayer water, but not bulk water, from quasi-two-dimensional (2D) ice to 2D liquid at room temperature due to resonance of the electromagnetic wave with the vibration mode of confined water. These findings are expected to improve the understanding of molecular transport at the atomic scale and potential physics in biology and to promote the applications of terahertz technology in desalination and biomedical science.