Enabling Graphene Oxide Nanosheets as Water Separation Membranes
Enabling Graphene Oxide Nanosheets as Water Separation Membranes
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DOI：
10.1021/es400571g
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发表时间：
2013-04-16
影响因子：
11.4
通讯作者：
Mi, Baoxia
中科院分区：
文献类型：
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作者：
Hu, Meng;Mi, Baoxia
我们报道了一种利用氧化石墨烯（GO）纳米片合成新型水分离膜的新方法，使得水能够通过GO层间的纳米通道流动，而不需要的溶质则因尺寸排阻和电荷效应被截留。该GO膜是通过在聚多巴胺涂层的聚砜支撑体上逐层沉积GO纳米片制成的，这些纳米片通过1,3,5 - 苯三甲酰氯进行交联。交联不仅为堆叠的GO纳米片提供了在水环境中克服其固有分散性所需的稳定性，还精细调节了GO纳米片的电荷、官能团和间距。然后我们测试了具有不同层数GO的合成膜，以展示其有趣的水分离性能。研究发现，GO膜通量在80到276升/平方米·小时·兆帕之间，大约是大多数商业纳滤膜的4 - 10倍。尽管现阶段开发的GO膜对一价和二价盐的截留率相对较低（6% - 46%），但它对亚甲基蓝表现出中等截留率（46% - 66%），对罗丹明 - WT表现出高截留率（93% - 95%）。在论文结尾我们强调，利用廉价GO材料的理想特性简便合成GO膜为改变其物理化学性质提供了大量机会，有可能使GO膜成为用于水分离应用的长期存在的薄膜复合聚酰胺膜的下一代、具有成本效益且可持续的替代品。
We report a novel procedure to synthesize a new type of water separation membrane using graphene oxide (GO) nanosheets such that water can flow through the nanochannels between GO layers while unwanted solutes are rejected by size exclusion and charge effects. The GO membrane was made via layer-by-layer deposition of GO nanosheets, which were cross-linked by 1,3,5-benzenetricarbonyl trichloride, on a polydopamine-coated polysulfone support. The cross-linking not only provided the stacked GO nanosheets with the necessary stability to overcome their inherent dispensability in water environment but also fine-tuned the charges, functionality, and spacing of the GO nanosheets. We then tested the membranes synthesized with different numbers of GO layers to demonstrate their interesting water separation performance. It was found that the GO membrane flux ranged between 80 and 276 LMH/MPa, roughly 4-10 times higher than that of most commercial nanofiltration membranes. Although the GO membrane in the present development stage had a relatively low rejection (6-46%) of monovalent and divalent salts, it exhibited a moderate rejection (46-66%) of Methylene blue and a high rejection (93-95%) of Rhodamine-WT. We conclude the paper by emphasizing that the facile synthesis of a GO membrane exploiting the ideal properties of inexpensive GO materials offers a myriad of opportunities to modify its physicochemical properties, potentially making the GO membrane a next-generation, cost-effective, and sustainable alternative to the long-existing thin-film composite polyamide membranes for water separation applications.