Journal of Membrane Science, Vol.537, 32-41, 2017
Hierarchically structured porous anion exchange membranes containing zwetterionic pores for ion separation
Hierarchically structured porous membranes have shown promising advantages over traditional membranes when used in separation technologies. These bio-inspired sophisticated structures provide a feasible scaffold to tailor membranes with desired functionalities for potential applications in ion separation. This study presents a unique approach to fabricating hierarchical structured porous membranes containing zwitterionic pores and investigates the impact of zwitterionic pores on membrane performance. The membranes were fabricated via a supported sol-gel strategy to facilitate the orientation and organisation of the functional groups in the silica network. Quaternised poly(2-dimethylaminoethanol-N-2,3-dimethylphenyl oxide) (QDAPPO) was used to form the main matrix, whereas an organosilane ionic liquid (IL) and 4-(hydroxymethyl) benzoic acid underwent electrostatic ion repulsion to form zwitterionic pores. The obtained membranes exhibited a superior proton diffusion coefficient of 0.0386 m h(-1) at 25 degrees C. Despite their high ionic characteristics, these hierarchical structured anion exchange membranes containing zwitterionic pores also had high mechanical and dimensional stability.
Keywords:Anion exchange membrane;Hierarchically structured porous structure;Zwitterionic pores;Ion separation;Diffusion dialysis