posted on 2022-06-10, 14:11authored byTobias Foller, Lukas Madauß, Dali Ji, Xiaojun Ren, K. Kanishka H. De Silva, Tiziana Musso, Masamichi Yoshimura, Henning Lebius, Abdenacer Benyagoub, Priyank V. Kumar, Marika Schleberger, Rakesh Joshi
Angstrom-confined solvents in 2D
laminates can travel through interlayer
spacings, through gaps between adjacent sheets, and via in-plane pores.
Among these, experimental access to investigate the mass transport
through in-plane pores is lacking. Our experiments allow an understanding
of this mass transport via the controlled variation of oxygen functionalities,
size and density of in-plane pores in graphene oxide membranes. Contrary
to expectations, our transport experiments show that higher in-plane
pore densities may not necessarily lead to higher water permeability.
We observed that membranes with a high in-plane pore density but a
low amount of oxygen functionalities exhibit a complete blockage of
water. However, when water–ethanol mixtures with a weaker hydrogen
network are used, these membranes show an enhanced permeation. Our
combined experimental and computational results suggest that the transport
mechanism is governed by the attraction of the solvents toward the
pores with functional groups and hindered by the strong hydrogen network
of water formed under angstrom confinement.