Aluminum fumarate MOF/PVDF hollow fiber membrane for enhancement of water flux and thermal efficiency in direct contact membrane distillation
Aluminum fumarate MOF/PVDF hollow fiber membrane for enhancement of water flux and thermal efficiency in direct contact membrane distillation
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富马酸铝 MOF/PVDF 中空纤维膜用于提高直接接触膜蒸馏中的水通量和热效率
DOI：
10.1016/j.memsci.2019.117204
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发表时间：
2019-10-15
影响因子：
9.5
通讯作者：
Xie, Zongli
中科院分区：
文献类型：
--
作者：
Cheng, Dongjian;Zhao, Lihua;Xie, Zongli
将聚合物的可加工性与多孔纳米添加剂的性能相结合的混合基质膜是提高膜蒸馏（MD）工艺性能的有效方法。本文制备了一种掺富马酸铝金属有机骨架（AlFu MOF）的新型疏水杂化PVDF中空纤维膜，并对其在直接接触膜蒸馏中的性能进行了实验和理论研究。结果表明，MOF颗粒的加入有效地增大了膜的有效孔隙率，提高了MD工艺的水通量和热效率。当MOF载荷为1 wt%时，膜的有效孔隙率增加了52.4%，膜的总传质系数增加了55.9%，膜的导热系数降低了38.6%，从而降低了MD的显热损失。在进料温度为40℃时，MOF/PVDF混合膜的水通量提高了50.5%，热效率提高了46.2% (0.58 vs 0.31)，在3.5 wt% NaCl溶液中，MOF/PVDF膜在50 h的脱盐试验中表现出稳定的通量，并保持了较高的除盐率（> 99.9%）。总的来说，本研究揭示了AlFu MOF添加剂对蒸馏过程中膜性能增强的积极作用。
Mixed matrix membranes combining the processibility of polymers with the properties of porous nano-additives is an effective method to enhance the performance of membrane distillation (MD) process. In this work, a new type of hydrophobic hybrid PVDF hollow fiber membranes doped with aluminum fumarate metal-organic frameworks (AlFu MOF) was fabricated and their performance in direct contact membrane distillation were studied experimentally and theoretically. The results showed that the addition of MOF particles efficiently enlarged the effective porosity of membrane and increased the water flux as well as the thermal efficiency of MD process. At 1 wt% MOF loading, the effective porosity of membrane was enlarged by 52.4%, which induced 55.9% increment in overall mass transfer coefficient of the hybrid membrane, and the thermal conductivity of the membrane was decreased by 38.6%, which contributed to the reduction of sensible heat loss of MD. Correspondingly, the experimental water flux of the hybrid 1 wt% MOF/PVDF membrane was improved by 50.5% and the thermal efficiency increased by 46.2% (0.58 vs 0.31) at a feed temperature of 40 degrees C. Moreover, the MOF/PVDF membrane exhibited stable flux and retained high salt rejection ( > 99.9%) for 3.5 wt% NaCl solution over a 50 h desalination test period. Overall, this study provides an insight into the positive effects of AlFu MOF additives on the enhancement of membrane performance in distillation process.