Unravelling the solvent flux behaviour of ceramic nanofiltration and ultrafiltration membranes
Unravelling the solvent flux behaviour of ceramic nanofiltration and ultrafiltration membranes
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DOI：
10.1016/j.memsci.2013.03.032
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发表时间：
2013-07-15
影响因子：
9.5
通讯作者：
Verhulst, K.
中科院分区：
文献类型：
--
作者：
Buekenhoudt, A.;Bisignano, F.;Verhulst, K.
为了增加对有机溶剂纳滤（OSN）基本过程的理解，进行了一项旨在澄清陶瓷纳滤和超滤膜的溶剂通量行为的研究。选择陶瓷膜是因为它们的非溶胀特性。纯水和11种不同的有机溶剂的变化进行了测量上的一系列不同的陶瓷膜的孔径直径范围从0.9 nm至100 nm。为了避免任何历史影响，每次通量测量都在新的膜上进行，通量结果以现象学的方式进行分析，并且在通量与溶剂粘度的乘积和溶剂的总汉森溶解度参数之间观察到常见的非常简单的线性关系。线性关系被发现为所有的膜，独立的膜孔径和膜材料。线性关系的斜率被发现以指数方式依赖于孔径直径和膜表面的极性。这一结果强调了粘度在溶剂传输中的重要性，但也强调了膜表面和溶剂之间的极性差异。推导出的非常简单的通量模型，允许直接预测任何溶剂或溶剂混合物的通量，一旦膜的水通量是已知的。在高孔隙尺寸端，现象学模型自然地根据需要转化为粘性流动或孔隙流动行为。该模型的一个尝试性的物理解释考虑到存在和扩展的水层吸附到这些membranes.This工作的总孔表面的亲水性膜的水通量给出了一个很好的指示其分子量截止（MWCO），因此，其在水中的分离性能。(C)0 2013爱思唯尔有限公司版权所有。
In order to increase the understanding of the underlying processes in organic solvent nanofiltration (OSN), a study has been undertaken aimed at clarifying the solvent flux behaviour of ceramic nanofiltration and ultrafiltration membranes. Ceramic membranes were chosen for their non-swelling character. Pure water and a variation of 11 different organic solvents were measured on a series of different ceramic membranes with pore-size diameters ranging from 0.9 nm up to 100 nm. To avoid any historical effects, each flux measurement was carried out on a new membrane.The flux results were analysed in a phenomenological way, and a common very simple linear relationship was observed between the product of flux and viscosity of the solvent, and the total Hansen solubility parameter of the solvent. The linear relationship was found for all membranes, independent of the membrane pore size and the membrane material. The slope of the linear relationship was found to depend exponentially on the pore-size diameter and on the polarity of the membrane surface. This result emphasizes the importance of viscosity in the solvent transport, but also of the polarity difference between membrane surface and solvent. The very simple flux model deduced, allows a straightforward prediction of the flux of any solvent or solvent mixture, once the water flux of the membrane is known. At the high pore-size end, the phenomenological model naturally transforms into the viscous-flow or pore-flow behaviour as required. A tentative physical explanation of the model takes into account the presence and extension of a water layer adsorbed to the total pore surface of these membranes.This work also shows that the water flux of a hydrophilic membrane gives a good indication of its molecular weight cut-off (MWCO), and therefore of its separation performance in water. (C)0 2013 Elsevier B.V. All rights reserved.