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Updated: Sep 14, 2025

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids
Published on: March 2, 2012
Gravitation-biased ion migration in aqueous solutions
Jooyoung Im1, J Carlos Santamarina2
1Physical Science and Engineering, King Abdullah University of Science and Technology KAUST, Thuwal, 23955, Saudi Arabia. jooyoung.im@kaust.edu.sa.
Abstract:
The gravity-biased drift of hydrated ions is assumed negligible and therefore disregarded in analysis and design. In this study, we reassess the impact of gravity on hydrated ion migration in aqueous solutions by subjecting six chloride salt solutions to controlled centrifugal acceleration across varying flight durations. The resulting data show that ion migration depends on both g-level and duration, providing clear evidence of gravitational bias. Based on the measured mobilities, gravity-induced effects should not be overlooked in systems extending over several meters or operating on century-long timescales. Recognizing gravity-driven migration has the potential to shift design paradigms, from industrial processes to the geological storage of nuclear waste.
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