Li Qian, Song Peng, Yang Yuye, Li Yan, Wang Naixin, An Quanfu
Beijing Key Laboratory for Green Catalysis and Separation, Department of Environmental and Chemical Engineering, Beijing University of Technology, Beijing 100124, China.
Nanomaterials (Basel). 2021 Dec 26;12(1):59. doi: 10.3390/nano12010059.
The pursuit of improved water purification technology has motivated extensive research on novel membrane materials to be carried out. In this paper, one-dimensional carboxylated carbon nanotubes (CNTs) were intercalated into the interlayer space of layered double hydroxide (LDH) to form a composite membrane for water purification. The CNTs/LDH laminates were deposited on the surface of the hydrolyzed polyacrylonitrile (PAN) ultrafiltration membrane through a vacuum-assisted assembly strategy. Based on the characterization of the morphology and structure of the CNTs/LDH composite membrane, it was found that the intercalation of CNT created more mass transfer channels for water molecules. Moreover, the permeance of the CNTs/LDH membrane was improved by more than 50% due to the low friction and rapid flow of water molecules in the CNT tubes. Additionally, the influence of preparation conditions on the separation performance was investigated using Evans blue (EB). Optimized fabrication conditions were given (the concentration of CoAl-LDH was 0.1 g/L and the weight ratio of CNTs was 2 wt.%). Next, the separation performances of the prepared CNTs/LDH composite membrane were evaluated using both single and mixed dye solutions. The results showed that the composite membrane obtained possessed a retention of 98% with a permeance of 2600 kg/(m·h·MPa) for EB, which was improved by 36% compared with the pristine LDH composite membrane. Moreover, the stability of the CNTs/LDH composite membrane was investigated in 100 h with no obvious permeance drop (less than 13%), which exhibited its great potential in water purification.
对改进水净化技术的追求促使人们对新型膜材料展开广泛研究。本文将一维羧基化碳纳米管（CNTs）插入层状双氢氧化物（LDH）的层间空间，以形成用于水净化的复合膜。通过真空辅助组装策略，将CNTs/LDH层状材料沉积在水解聚丙烯腈（PAN）超滤膜表面。基于对CNTs/LDH复合膜形态和结构的表征，发现CNT的插入为水分子创造了更多传质通道。此外，由于水分子在CNT管中摩擦力低且流动迅速，CNTs/LDH膜的渗透率提高了50%以上。此外，使用伊文思蓝（EB）研究了制备条件对分离性能的影响。给出了优化的制备条件（CoAl-LDH浓度为0.1 g/L，CNTs重量比为2 wt.%）。接下来，使用单一和混合染料溶液评估制备的CNTs/LDH复合膜的分离性能。结果表明，所得复合膜对EB的截留率为98%，渗透率为2600 kg/(m·h·MPa)，与原始LDH复合膜相比提高了36%。此外，对CNTs/LDH复合膜在100小时内的稳定性进行了研究，渗透率无明显下降（小于13%），这表明其在水净化方面具有巨大潜力。
