Separation Performance of Anion Exchange Membranes with Electrodialysis

PROJECT NUMBER: 9

AUTHOR: Joshua Cedillos, Chemical and Biological Engineering

MENTOR: Andrew Herring, Chemical and Biological Engineering | MENTOR: Ivy Wu, Chemical and Biological Engineering

ABSTRACT

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Water desalination is a complex and important industry, requiring the development of practical treatment processes capable of processing a multitude of different wastewaters from municipal, agricultural, and industrial sectors. Ion exchange membranes have the potential to serve a vital role in the development of more robust and efficient treatment processes such as electrodialysis, but no commercial standard yet exists for anion exchange membranes (AEM). In this work, we have developed a robust triblock AEM and elucidated the effects of block ratios on membrane separation performance. Specifically, we investigated how different block ratios affect conductivity, selectivity, resistance, and permeability. In electrodialysis, ion separation is induced through electrical potential by separating anions through AEMs and cation through CEMs. We have developed an ABA triblock copolymer of polychloromethylstyrene-polycyclooctene-polychloromethylstyrene (PCMS-PCOE-PCMS) quaternized with methyl piperidine. The AEM was implemented into a custom-built electrodialysis cell to gauge its separation performance of a 0.1M sodium chloride solution under a range of applied current. We found that large block ratios led to larger hydrophilic channels, increasing the permeability of the membrane but at the cost of separation performance. Small block ratios created small hydrophilic channels with higher selectivity but lower permeability.

VISUAL PRESENTATION

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AUTHOR BIOGRAPHY

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Joshua Cedillos is currently a first-generation undergraduate freshman at Colorado School of Mines. He is planning to major in Chemical and Biological Engineering, and minor in biomedical engineering. Starting his undergraduate career, Joshua got accepted to the FIRST fellowship program and worked consistently with PhD candidate mentor, Ivy Wu. This freshman year, Joshua had his first research project and initial stepping stones in a lab environment. Joshua has researched and learned about methods of water desalination regarding the mechanisms of electrodialysis. Joshua learned proper lab etiquette, chemical solutions, and processes that aided with the project. The research that Joshua would like to do one day is medicine and medical purposes.

Sponsored by Phillips 66