Gohil G S, Nagarale R K, Binsu V V, Shahi Vinod K
Electro-Membrane Processes Division, Central Salt & Marine Chemicals Research Institute, Bhavnagar-364002, India.
J Colloid Interface Sci. 2006 Jun 15;298(2):845-53. doi: 10.1016/j.jcis.2005.12.069. Epub 2006 Feb 7.
Highly charged cation permeable composite membranes were prepared by blending of sulfonated poly(ether sulfone) (SPES) with sulfonated poly(ether ether ketone) (SPEEK) in 0 to 90% weight ratio, to adjust the hydrophobic properties and ion selective nature. Extent of sulfonation was confirmed by 1H NMR and ion exchange capacity and degree of sulfonation depending on blending composition. These membranes were characterized as a function of weight fraction of SPEEK by recording ion-exchange capacity, water uptake, thermogravimetric analysis, membrane conductivity and membrane potential in equilibration with different electrolytic solutions. Membrane permselectivity and solute flux were estimated using these data on the basis of non-equilibrium thermodynamic principles and for observing the selectivity of different membranes for mono- or bivalent counter-ions. It was observed that relative selectivity for monovalent in comparison to bivalent counter-ions were increased with the decrease in SPEEK content in the composite membrane matrix. The range of SPEEK content in the blend from 60 to 80% appears the most suitable for the selective separation of monovalent ions from bivalent ions. Furthermore, highly charged nature and stabilities of these membranes extend their applications for the electro-assisted separations of similarly charged ions as well as other electro-membrane processes.
通过将磺化聚醚砜（SPES）与磺化聚醚醚酮（SPEEK）按0至90%的重量比混合来制备高电荷阳离子渗透复合膜，以调节其疏水性能和离子选择性。通过1H NMR、离子交换容量以及取决于共混组成的磺化度来确定磺化程度。通过记录离子交换容量、吸水率、热重分析、膜电导率以及与不同电解液平衡时的膜电位，对这些膜进行了表征，表征结果作为SPEEK重量分数的函数。基于非平衡热力学原理，利用这些数据估算了膜的选择透过性和溶质通量，以观察不同膜对单价或二价抗衡离子的选择性。观察到，与二价抗衡离子相比，复合膜基质中随着SPEEK含量的降低，对单价离子的相对选择性增加。共混物中SPEEK含量在60%至80%的范围似乎最适合从二价离子中选择性分离单价离子。此外，这些膜的高电荷性质和稳定性扩展了它们在电辅助分离带相同电荷离子以及其他电膜过程中的应用。
