Atomistic simulation study of GO/HKUST-1 MOF membranes for seawater desalination via pervaporation

• Main Authors: Dahanayaka, Madhavi, Babicheva, Rita, Chen, Zhong, Law, Adrian Wing-Keung, Wu, Mao See, Zhou, Kun
• Other Authors: Interdisciplinary Graduate School (IGS)
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Environmental engineering; Molecular Dynamics; Pervaporation
• Online Access: https://hdl.handle.net/10356/161228
• Institution: Nanyang Technological University

HKUST-1 is one of the most widely used metal-organic frameworks (MOFs) in gas separation. However, its application in liquid separation is limited due to its relatively low stability in water caused by the interaction of coordinatively unsaturated Cu sites with the water molecules. In this study, molecular dynamics simulations of the pervaporation process are conducted to investigate the desalination performance of composite membranes composed of an HKUST-1 sheet and graphene oxide (GO) layers introduced to enhance its stability in water. The membrane configurations of single or double-layered GO on both sides of the HKUST-1 thin sheet are considered. It is revealed that the composite membranes demonstrate excellent water flux higher than that of ZIF-8 and GO membranes reported earlier. All the considered membranes show complete salt rejection. The water affinity of Cu atoms decreases with the addition of GO layers that improve the stability of HKUST-1 in water. However, this increase diminishes the permeate flux due to the presence of additional barriers in the molecular paths. The simulation results suggest that the HKUST-1 sheet with single-layered GO is a suitable material for pervaporation membrane fabrication.