ZIF-8 particle size effects on reverse osmosis performance of polyamide thin-film nanocomposite membranes: Importance of particle deposition
ZIF-8 particle size effects on reverse osmosis performance of polyamide thin-film nanocomposite membranes: Importance of particle deposition
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DOI：
10.1016/j.memsci.2018.10.015
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发表时间：
2019-01-15
影响因子：
9.5
通讯作者：
Park, Ho Bum
中科院分区：
文献类型：
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作者：
Lee, Tae Hoon;Oh, Jee Yeon;Park, Ho Bum
基于纳米材料嵌入的聚酰胺层的薄膜纳米复合材料（TFN）膜作为用于反渗透（RO）脱盐的节能材料已被广泛研究。尽管几项研究已经报道了具有沸石咪唑骨架的TFN膜（例如，ZIF-8）显示出改善的RO性能，这归因于其固有的微孔性和高比表面积，关于ZIF-8纳米颗粒在选择性聚酰胺层中的作用的深入研究尚未发表。在这里，我们合成了具有不同平均尺寸（60、150和250 nm）的ZIF-8纳米颗粒，并研究了颗粒尺寸对TFN膜分离性能的影响。有趣的是，发现在聚酰胺层的界面聚合之前，ZIF-8纳米颗粒在微孔聚砜（PSf）载体上的沉积受ZIF-8粒度的影响。小尺寸的ZIF-8纳米颗粒表现出最高的表面覆盖率，这与经典的颗粒沉积理论一致。ZIF-8纳米颗粒与聚酰胺基体之间的界面面积随颗粒尺寸而变化，最终影响TFN膜的反渗透性能。我们的研究结果首次揭示了颗粒沉积量之前，界面聚合可以强烈影响颗粒的大小，强调颗粒沉积的重要性，为进一步研究纳米颗粒嵌入TFN膜。
Thin-film nanocomposite (TFN) membranes based on nanomaterial-embedded ultrathin polyamide layers have been extensively studied as an energy-efficient material for reverse osmosis (RO) desalination. Although several studies have reported that TFN membranes with zeolitic imidazole frameworks (e.g., ZIF-8) showed improved RO performances, attributed to its intrinsic microporosity and high specific surface area, an in-depth study on the role of ZIF-8 nanoparticles in selective polyamide layers has not yet been published. Here we synthesized ZIF-8 nanoparticles with different average sizes (60, 150, and 250 nm) and investigated the effects of particle size on the separation performance of TFN membranes. Interestingly, it was found that the deposition of ZIF-8 nanoparticles on the microporous polysulfone (PSf) support prior to interfacial polymerization of the polyamide layer was influenced by ZIF-8 particle size. Small-sized ZIF-8 nanoparticles showed the highest surface coverage, which is consistent with the classical particle deposition theories. The interface area between ZIF-8 nanoparticles and polyamide matrix varied with particle size, ultimately affecting the RO performance of TFN membranes. Our results firstly reveal that the amount of particle deposition prior to interfacial polymerization could be strongly influenced by particle size, emphasizing the importance of particle deposition for the further studies on nanoparticle-embedded TFN membranes.