Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 11, Issue 8, Pages 8483-8491Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.9b00492
Keywords
graphene oxide; membrane; edge-functionalization; self-diffusion; water transport; molecular dynamics
Funding
- Australian Government Department of Industry, Innovation, and Science through the Australia-China Science and Research Fund [ACSRF48154]
- National Key Research and Development Program of China (International S&T Cooperation Program, ISTCP) [2016YFE0101200]
Ask authors/readers for more resources
Graphene oxide (GO) membranes assembled by GO nanosheets exhibit high water flux because of the unique water channels formed by their functionalized layer-by-layer structure. Although water transport in the GO membrane is in principle influenced by the functional groups at the edges of GO nanosheets, this is yet to be fully understood. To fill this knowledge gap, molecular dynamics simulation was employed in this work to gain insights into the influences of three typical edge functional groups of GO nanosheets: carboxyl (COOH), hydroxyl (OH), and hydrogen (H). A well-controlled numerical analysis with complete isolation of the functional groups at the edges was undertaken. The results reveal that the COOH group has a negative impact on water transport because of its relatively large steric geometric structure, which resists water flow. By contrast, the OH group promotes water transport by uniquely pulling water molecules across the nanosheet layer because of its relatively stronger interaction with water. The H atom promotes water transport as well, mainly because of its low-resistance steric structure. Moreover, the size of the inter-edge hub has an apparent impact on the influence of these functional groups on water transport. The results suggest that in the design of high water flux GO membranes, it would be strategic to remove COOH edge functional groups while maintaining a mixture of OH and H edge functional groups.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available