(373k) Investigation of Correlation Between Membrane Characteristics and Rejection Rate of Ions

As a growing global population and development of industry, water consumption has shown an obvious rising trend. However, the available water resource is limited and conventional water filtration processes need not only huge amounts of energy but large-scale infrastructure. To break this, understanding of ionic behavior in the region near a charged surface is important for development of small-scale water filtration devices. In this study, formation of ion depletion zones and water filtration performance were experimentally investigated using membranes with varying surface charges and pore sizes. These membranes were fabricated using graphene oxide, poly(sodium 4-styrenesulfonate), and sodium dodecyl sulfate. The respective rejection rate of the fluorescent dyes and the ionic solutions was noticeably high as revealed by the mechanism of Donnan exclusion theory and size exclusion. In addition, the proposed membrane exhibited an antimicrobial property. These results suggested that the proposed filtration membrane can be hired as a compact and small-scale water filtration device because of its strong potential for desalinating brackish water.

*This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. NRF-2020R1C1C1003813).