TY - JOUR
T1 - Diffusiophoresis in Multivalent Electrolytes
AU - Wilson, Jessica L.
AU - Shim, Suin
AU - Yu, Yingxian Estella
AU - Gupta, Ankur
AU - Stone, Howard A.
N1 - Funding Information:
We gratefully acknowledge Professor Robert Prud'homme and Dr. Navid Bizmark (Department of Chemical and Biological Engineering Princeton University) for insightful discussions. This work was financially supported by the National Science Foundation (CBET-1702693). S.S. and H.A.S. directed the experimental research, and A.G. and H.A.S. directed the modeling. S.S. and J.L.W. designed the experiments. J.L.W. performed the experiments. Y.E.Y. and J.L.W. performed the image processing and data analysis. A.G. performed the modeling and developed the model. A.G., S.S., H.A.S., and J.L.W. wrote the manuscript.
Funding Information:
We gratefully acknowledge Professor Robert Prud’homme and Dr. Navid Bizmark (Department of Chemical and Biological Engineering, Princeton University) for insightful discussions. This work was financially supported by the National Science Foundation (CBET-1702693). S.S. and H.A.S. directed the experimental research, and A.G. and H.A.S. directed the modeling. S.S. and J.L.W. designed the experiments. J.L.W. performed the experiments. Y.E.Y. and J.L.W. performed the image processing and data analysis. A.G. performed the modeling and developed the model. A.G., S.S., H.A.S., and J.L.W. wrote the manuscript.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/6/30
Y1 - 2020/6/30
N2 - Diffusiophoresis is the spontaneous movement of colloidal particles in a concentration gradient of solutes. As a small-scale phenomenon that harnesses energy from concentration gradients, diffusiophoresis may prove useful for passively manipulating particles in lab-on-a-chip applications as well as configurations involving interfaces. Though naturally occurring ions are often multivalent, experimental studies of diffusiophoresis have been mostly limited to monovalent electrolytes. In this work, we investigate the motion of negatively charged polystyrene particles in one-dimensional salt gradients for a variety of multivalent electrolytes. We develop a one-dimensional model and obtain good agreement between our experimental and modeling results with no fitting parameters. Our results indicate that the ambipolar diffusivity, which is dependent on the valence combination of cations and anions, dictates the speed of the diffusiophoretic motion of the particles by controlling the time scale at which the electrolyte concentration evolves. In addition, the ion valences also modify the electrophoretic and chemiphoretic contributions to the diffusiophoretic mobility of the particles. Our results are applicable to systems where the chemical concentration gradient is comprised of multivalent ions, and motivate future research to manipulate particles by exploiting ion valence.
AB - Diffusiophoresis is the spontaneous movement of colloidal particles in a concentration gradient of solutes. As a small-scale phenomenon that harnesses energy from concentration gradients, diffusiophoresis may prove useful for passively manipulating particles in lab-on-a-chip applications as well as configurations involving interfaces. Though naturally occurring ions are often multivalent, experimental studies of diffusiophoresis have been mostly limited to monovalent electrolytes. In this work, we investigate the motion of negatively charged polystyrene particles in one-dimensional salt gradients for a variety of multivalent electrolytes. We develop a one-dimensional model and obtain good agreement between our experimental and modeling results with no fitting parameters. Our results indicate that the ambipolar diffusivity, which is dependent on the valence combination of cations and anions, dictates the speed of the diffusiophoretic motion of the particles by controlling the time scale at which the electrolyte concentration evolves. In addition, the ion valences also modify the electrophoretic and chemiphoretic contributions to the diffusiophoretic mobility of the particles. Our results are applicable to systems where the chemical concentration gradient is comprised of multivalent ions, and motivate future research to manipulate particles by exploiting ion valence.
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U2 - 10.1021/acs.langmuir.9b03333
DO - 10.1021/acs.langmuir.9b03333
M3 - Article
C2 - 32004429
AN - SCOPUS:85087433600
SN - 0743-7463
VL - 36
SP - 7014
EP - 7020
JO - Langmuir
JF - Langmuir
IS - 25
ER -