The trade-off between membrane permeability and selectivity and membrane fouling, including both physical and bio-fouling, are major challenges that limit the practical application of nanofiltration (NF) membranes. In order to address these issues simultaneously, multifunctional membranes with maximized water permeability/salt selectivity and enhanced antifouling and antibacterial properties are desired. In this work, we prepare a novel multifunctional thin film nanocomposite (TFN) NF membrane by embedding cellulose nanocrystal/silver (CNC/Ag) nanocomposites into a polyamide layer. The CNC/Ag TFN NF membranes exhibit excellent properties by taking advantage of both CNCs, a highly hydrophilic, low-cost, bio-renewable, and environmentally friendly nanomaterial, and Ag nanoparticles, one of the most effective bactericidal materials. With the incorporation of only 0.01 wt% CNC/Ag nanocomposites, a high pure water permeability (25.4 L m⁻² h⁻¹ bar⁻) and a high rejection rate of Na₂SO₄ (99.1%) of the CNC/Ag TFN NF membrane can be achieved, respectively. Besides, the membrane also exhibits exceptional antifouling (flux recovery ratio reaches 92.6% for humic acid) and antibacterial performance (99.4% reduction of Escherichia coli viability). Ag⁺ leaching tests also demonstrate the good stability of Ag nanoparticles in the active thin-film layer of the CNC/Ag NF membranes. These findings have strong positive implications for the development of next-generation high performance NF membranes for water treatment.

中文翻译：

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具有多功能特性的纤维素纳米晶体/银（CNC / Ag）薄膜纳米复合纳米过滤膜

膜渗透性和选择性以及膜污染（包括物理污染和生物污染）之间的权衡是限制纳米过滤（NF）膜实际应用的主要挑战。为了同时解决这些问题，需要具有最大的透水性/盐选择性和增强的防污和抗菌性能的多功能膜。在这项工作中，我们通过将纤维素纳米晶体/银（CNC / Ag）纳米复合材料嵌入聚酰胺层中，制备了一种新型的多功能薄膜纳米复合材料（TFN）NF膜。CNC / Ag TFN NF膜通过利用高度亲水，低成本，生物可再生且环保的纳米材料CNC和最有效的杀菌材料之一Ag纳米颗粒，展现出优异的性能。^-2 ħ ^-1巴^- ）和Na的高废品率₂ SO ₄的CNC /银TFN NF膜可分别实现的（99.1％）。此外，该膜还具有出色的防污性能（腐殖酸的通量回收率达到92.6％）和抗菌性能（大肠埃希氏菌活力降低了99.4％）。Ag ⁺浸出试验还表明，Ag纳米颗粒在CNC / Ag NF膜的活性薄膜层中具有良好的稳定性。这些发现对用于水处理的下一代高性能NF膜的开发具有强烈的积极意义。