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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Scalable Graphene-Based Membranes for Ionic Sieving with Ultrahigh Charge Selectivity

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Hong, Seunghyun ; Constans, Charlotte ; Martins, Marcos Vinicius Surmani ; Seow, Yong Chin ; Guevara Carrio, Juan Alfredo ; Garaj, Slaven
Total Authors: 6
Document type: Journal article
Source: Nano Letters; v. 17, n. 2, p. 728-732, FEB 2017.
Web of Science Citations: 41

Nanostructured graphene-oxide (GO) laminate membranes, exhibiting ultrahigh water flux, are excellent candidates for next generation nanofiltration and desalination membranes, provided the ionic rejection could be further increased without compromising the water flux. Using microscopic drift diffusion experiments, we demonstrated the ultrahigh charge selectivity for GO membranes, with more than order of magnitude difference in the permeabilities of cationic and anionic species of equivalent hydration radii. Measuring diffusion of a wide range of ions of different size and charge, we were able to clearly disentangle different physical mechanisms contributing to the ionic sieving in GO membranes: electrostatic repulsion between ions and charged chemical groups; and the compression of the ionic hydration shell within the membrane's nanochannels, following the activated behavior. The charge-selectivity allows us to rationally design membranes with increased ionic rejection and opens up the field of ion exchange and electrodialysis to the GO membranes. (AU)

FAPESP's process: 13/21190-2 - CVD growth of graphene/h-BN layers, structural characterization and study of layers: water interaction
Grantee:Juan Alfredo Guevara Carrió
Support type: Scholarships abroad - Research