期刊
ACS Sustainable Chemistry & Engineering
标题
Antibacterial Thin-Film Nanocomposite Membranes Incorporated with Graphene Oxide Quantum Dot-Mediated Silver Nanoparticles for Reverse Osmosis Application
作者
Li Yu, Wen Zhou, Yiming Li, Quanzhu Zhou, Haibo Xu, Baoyu Gao, Zhining Wang
摘要
The trade-off between selectivity and permeability as well as membrane biofouling are major limitations of thin-film composite (TFC) membranes. Graphene oxide quantum dot (GOQD) has aroused wide interest in membrane preparation because of the hydrophilic groups and one-atom-thick structure with lateral dimensions of 3–20 nm. GOQD could improve the permeability by providing additional water channels in membranes without compromising the selectivity. As an effective bactericidal material, silver nanoparticles (Ag) were uniformly deposited on GOQD by a facile method. The structure of the GOQD/Ag nanocomposite was verified by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy, and Raman spectroscopy. Subsequently, GOQD/Ag was embedded in the polyamide (PA) selective layer using an interfacial polymerization method to obtain thin-film nanocomposite (TFN-GOQD/Ag) membranes. The TFN membrane prepared at optimized conditions demonstrated a water flux of 39.1 L·m–2·h–1 and a NaCl rejection rate of 98.9% at 16 bar, reflecting a remarkable promotion in the flux (44.3%) compared with the pristine TFC membrane. Furthermore, owing to the synergistic effect of GOQD and Ag, the TFN-GOQD/Ag200 membrane possessed prominent bactericidal capacity against both Gram-negative Escherichia coli (98.6%) and Gram-positive Staphylococcus aureus(96.5%). The bactericidal mechanism was analyzed using a live/dead fluorescent imaging assay, scanning electron microscopy, morphology analysis, and reactive oxygen species detection. Furthermore, the bactericidal capacity of the TFN membrane was also measured via silver ion leaching and during extended practical application. This work demonstrates a new way to facilely prepare reverse osmosis membranes with prominent separation performance and excellent antibacterial and fouling resistance capacities.
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