Graphene smart membranes can control water
23 July 2018
Researchers of the University of Manchester's National Graphene Institute and the CMT group at the University of Antwerp have achieved a long-sought-after objective of electrically controlling water flow through membranes.
This is the latest exciting membranes development benefitting from the unique properties of graphene. The new research opens up an avenue for developing smart membrane technologies and could revolutionise the field of artificial biological systems, tissue engineering and filtration.
Graphene is capable of forming a tuneable filter or even a perfect barrier when dealing with liquids and gases. New 'smart' membranes developed using an inexpensive form of graphene called graphene oxide, have been demonstrated to allow precise control of water flow by using an electrical current. The membranes can even be used to completely block water from passing through when required.
The Manchester team, led by Professor Rahul Nair, embedded conductive filaments within the electrically insulating graphene oxide membrane. An electric current passed through these nano-filaments created a large electric field which ionises the water molecules and thus controls the water transport through the graphene capillaries in the membrane.
Prof Nair said: "This new research allows us to precisely control water permeation, from ultrafast permeation to complete blocking. Our work opens up an avenue for further developing smart membrane technologies."
The achievement of electrical control of water flow through membranes is a step change because of its similarity to several biological process where the main stimuli are electrical signals. Controlled water transport is a key for renal water conservation, regulation of body temperature and digestion. The reported electrical control of water transport through graphene membranes therefore opens a new dimension in developing artificial biological systems and advanced nanofluidic devices for various applications.
The Condensed Matter Theory group, part of the Nano Center of Excellence, led by Prof. Francois Peeters provided theoretical support for the modelling and interpretation of the results. The results were published in the July 12 issue of Nature: doi: 10.1038/s41586-018-0292-y.
Read the full article at Phys.org
Credit: University of Manchester