title: Thin-Film Nanocomposite (TFN) Membranes Incorporated with Super-Hydrophilic Metal-Organic Framework (MOF) UiO-66: Toward Enhancement of Water Flux and Salt Rejection.
abstract: Zirconiumv (IV)-carboxylate metal-organic framework (MOF) UiO-66 nanoparticles were successfully synthesized and incorporated in the polyamide (PA) selective layer to fabricate novel thin-film nanocomposite (TFN) membranes. Compared to unmodified pure polyamide thin-film composite (TFC) membranes, the incorporation of UiO-66 nanoparticles significantly changes the membrane morphology and chemistry, leading to an improvement of intrinsic separation properties due to the molecular sieving and superhydrophilic nature of UiO-66 particles. The best performing TFN-U2 (0.1 wt % particle loading) membrane not only shows a 52% increase of water permeability but also maintains salt rejection levels (∼95%) similar to the benchmark. The effects of UiO-66 loading on the forward osmosis (FO) performance were also investigated. Incorporation of 0.1 wt % UiO-66 produced a maximum water flux increase of 40% and 25% over the TFC control under PRO and FO modes, when 1 M NaCl was used as the draw solution against deionized water feed. Meanwhile, solute reverse flux was maintained at a relatively low level. In addition, TFN-U2 membrane displayed a relatively linear increase in FO water flux with increasing NaCl concentration up to 2.0 M, suggesting a slightly reduced internal concentration polarization effect. To our best knowledge, the current study is the first to consider implementation of Zr-MOFs (UiO-66) onto TFN-FO membranes.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 117585, Singapore.
authors.forename: Dangchen
authors.initials: D
authors.lastname: Ma
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 117585, Singapore.
authors.forename: Shing Bo
authors.initials: SB
authors.lastname: Peh
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 117585, Singapore.
authors.forename: Gang
authors.initials: G
authors.lastname: Han
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 117585, Singapore.
authors.forename: Shing Bor
authors.identifier: http://orcid.org/0000-0003-1454-9865
authors.initials: SB
authors.lastname: Chen
keywords: UiO-66; forward osmosis (FO); internal concentration polarization (ICP); metal−organic framework (MOF); seawater desalination; thin-film nanocomposite (TFN)