Modeling the water permeability and water/salt selectivity tradeoff in polymer membranes
Modeling the water permeability and water/salt selectivity tradeoff in polymer membranes
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DOI：
10.1016/j.memsci.2016.08.035
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发表时间：
2016-12
影响因子：
9.5
通讯作者：
Huan Zhang;Geoffrey M. Geise
中科院分区：
文献类型：
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作者：
Huan Zhang;Geoffrey M. Geise
提出了一个理论框架来模拟所观察到的水/盐的渗透性，扩散性和吸附选择性的权衡关系与水的渗透性，扩散和吸附系数。盐吸附建模使用静电（或介电）排除方法。水和盐的扩散采用受阻扩散和自由体积理论建模。这里建议的建模方法相比，一组水和盐的传输性能的数据测量使用各种各样的聚合物。模型描述了在权衡关系中观察到的一般趋势，但也描述了助溶剂-聚合物相互作用和/或其他系统特定效应可能显著的情况。该方法还强调了在分析水在水合聚合物中的扩散时对流参考系和热力学校正因子的重要性。这些修正讨论的框架内的实验数据从各种水合聚合物系统。扩展的权衡关系的数据集和理论框架有助于扩大洞察力的基本现象，在聚合物膜的脱盐应用中的水和盐的运输。
A theoretical framework is proposed to model the observed water/salt permeability, diffusivity, and sorption selectivity tradeoff relationships with water permeability, diffusion, and sorption coefficients. Salt sorption is modeled using an electrostatic (or dielectric) exclusion approach. Water and salt diffusion are modeled using hindered diffusion and free volume theories. The modeling approach suggested here is compared to a set of water and salt transport property data measured using a wide variety of polymers. The models describe the general trends observed in the tradeoff relationships but also situations where penetrant-polymer interactions and/or other system specific effects are likely significant. The approach also highlights the importance of convective frame of reference and thermodynamic correction factors in the analysis of water diffusion in hydrated polymers. These corrections are discussed within the framework of experimental data from a variety of hydrated polymer systems. The expanded tradeoff relationship data set and theoretical framework help to expand insight into the fundamental phenomena that govern water and salt transport in polymer membranes for desalination applications.