1. Crossly charged microfluidic device for spontaneous filtration without an external power supply.
- Author
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Kim, Kiwoong and Lee, Sang Joon
- Subjects
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POWER resources , *FILTERS & filtration , *MICROFLUIDIC devices , *SURFACE charges , *BRACKISH waters , *WATER - Abstract
Spontaneous filtration without a power supply was investigated using highly charged precursor mixtures instead of recognized microfluidic desalination techniques. The proposed filtration method consisted of a main channel (depth: 1 mm) and shallow channels (depth: 400 μm) in which the precursor mixture was injected. The filtration performance of the proposed device was evaluated by injecting a fluorescent dye that moved toward the centerline of the main channel. The respective rejection rates of CaCl 2 , NaCl, CaSO 4 , and Na 2 SO 4 were 3.16%, 30.13%, 43.74%, and 36.32%, respectively. This trend can be explained by the mechanism of Donnan exclusion theory. The focusing of charged species toward the centerline of the main channel was caused by highly charged surfaces. The proposed filtration method exhibited a migration of charged microparticles toward a certain direction. This particle migration behavior was consistent with the simulation data. These results suggested that the proposed filtration method had strong potential for desalinating brackish water or salty surface water without an external power supply. • A spontaneous filtration of ions and charged particles without an external electrical power supply. • Crossly charged channel surfaces had the same surface charge between diagonal-directional shallow channels. • The proposed method exhibited a noticeable filtration performance by focusing charged materials toward a certain direction. • This work can be considered a promising paradigm of nature-inspired desalination technology. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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