Transport of small and neutral solutes through reverse osmosis membranes: Role of skin layer conformation of the polyamide film
Transport of small and neutral solutes through reverse osmosis membranes: Role of skin layer conformation of the polyamide film
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DOI：
10.1016/j.memsci.2018.02.069
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发表时间：
2018-05-15
影响因子：
9.5
通讯作者：
Nghiem, Long D.
中科院分区：
文献类型：
--
作者：
Fujioka, Takahiro;O'Rourke, Brian E.;Nghiem, Long D.
反渗透（RO）膜的聚酰胺皮层的特点是使用先进的和互补的分析技术，以调查饮用水回用中出现的问题-N-亚硝基二甲胺（NDMA）和N-亚硝基甲基乙胺（NMEA）的污染物的渗透机制。本研究使用了五种具有相似膜性能的RO膜样品。五个RO膜样品跨越大范围的水渗透性（0.9-5.8 L/m（2）h bar）以及NDMA（9-66%）和NMEA（3-29%）的渗透。尽管五种RO膜之间存在这些差异，但使用正电子湮没寿命谱、原子力显微镜和场发射扫描电子显微镜对皮层进行的表征显示，它们的自由体积孔半径（0.270-0.275 nm）、有效表面积（198-212%）和皮层厚度（30-35 nm）几乎没有变化。结果表明，可能存在其他RO皮层特性，例如除了自由体积孔尺寸和皮层厚度之外的聚酰胺皮层内的突起的互连性，这也可以控制水和溶质渗透。
The polyamide skin layer of reverse osmosis (RO) membranes was characterised using advanced and complementary analytical techniques to investigate the mechanisms underlying the permeation of contaminants of emerging concern in potable water reuse - N-nitrosodimethylamine (NDMA) and N-nitrosomethylethylamine (NMEA). This study used five RO membrane samples with similar membrane properties. The five RO membrane samples spanned over a large range of water permeance (0.9-5.8 L/m(2) h bar) as well as permeation of NDMA (9-66%) and NMEA (3-29%). Despite these differences among the five RO membranes, characterisations of the skin layer using positron annihilation lifetime spectroscopy, atomic force microscopy and field emission scanning electron microscopy revealed almost no variation in their free-volume hole-radius (0.270-0.275 nm), effective surface area (198-212%) and thickness (30-35 nm) of the skin layer. The results suggest that there could be other RO skin layer properties, such as the interconnectivity of the protuberances within the polyamide skin layer additional to the free-volume hole-size and thickness of the skin layer, which can also govern water and solute permeation.