(521c) Ion Transport through Sulfonated Polymer Membranes for Desalination Applications

Fundamental understanding of ion transport in polymer membranes for desalination applications is critical to the development of future generations of membrane materials. Here, sulfonated and highly charged poly(arylene ether sulfone) and styrenic pentablock copolymer membranes have been evaluated for ion transport. Sulfonated polymers are of special interest for desalination applications due to evidence of favorable tolerance to chemicals such as the chlorine used in water treatment. Favorable chemical tolerance and the highly charged nature of sulfonated polymers differentiate these materials from traditional desalination membranes. Both the poly(arylene ether sulfone) and styrenic pentablock copolymer materials are of interest for future desalination membrane applications due to favorable water/ion selectivity and permeability properties. Here, transport of sodium and chloride ions through these materials has been analyzed in terms of the solution-diffusion model for transport through non-porous materials. In this model, penetrant permeability is given as the product of the solubility of the penetrant and the diffusion coefficient of the penetrant in the polymer matrix. Thus, in this work, ionic transport is presented in terms of ionic permeability, ionic partitioning (solubility), and ionic diffusion for polymer materials with varying degrees of sulfonation.