### Abstract

The streaming potential is generated by the electrokinetic flow effect within the electrical double layer of a charged solid surface. Surface charge properties are commonly quantified in terms of the zeta potential obtained by computation with the Helmholtz-Smoluchowski (H-S) equation following experimental measurement of streaming potential. In order to estimate a rigorous zeta potential for cone-shaped microchannel, the correct H-S equation is derived by applying the Debye-Hückel approximation and the fluid velocity of diverging flow on the specified position. The present computation provides a correction ratio relative to the H-S equation for straight cylindrical channel and enables us to interpret the effects of the channel geometry and the electrostatic interaction. The correction ratio decreases with increasing of diverging angle, which implies that smaller zeta potential is generated for larger diverging angle. The increase of Debye length also reduces the correction ratio due to the overlapping of the Debye length inside of the channel. It is evident that as the diverging angle of the channel goes to nearly zero, the correction ratio converges to the previous results for straight cylindrical channel.

Original language | English |
---|---|

Pages (from-to) | 120-126 |

Number of pages | 7 |

Journal | Journal of Colloid and Interface Science |

Volume | 266 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2003 Oct 1 |

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### All Science Journal Classification (ASJC) codes

- Electronic, Optical and Magnetic Materials
- Biomaterials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry

### Cite this

*Journal of Colloid and Interface Science*,

*266*(1), 120-126. https://doi.org/10.1016/S0021-9797(03)00576-9

}

*Journal of Colloid and Interface Science*, vol. 266, no. 1, pp. 120-126. https://doi.org/10.1016/S0021-9797(03)00576-9

**Estimation of zeta potential by electrokinetic analysis of ionic fluid flows through a divergent microchannel.** / Chun, Myung Suk; Lee, Sangyup; Yang, Seung Man.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Estimation of zeta potential by electrokinetic analysis of ionic fluid flows through a divergent microchannel

AU - Chun, Myung Suk

AU - Lee, Sangyup

AU - Yang, Seung Man

PY - 2003/10/1

Y1 - 2003/10/1

N2 - The streaming potential is generated by the electrokinetic flow effect within the electrical double layer of a charged solid surface. Surface charge properties are commonly quantified in terms of the zeta potential obtained by computation with the Helmholtz-Smoluchowski (H-S) equation following experimental measurement of streaming potential. In order to estimate a rigorous zeta potential for cone-shaped microchannel, the correct H-S equation is derived by applying the Debye-Hückel approximation and the fluid velocity of diverging flow on the specified position. The present computation provides a correction ratio relative to the H-S equation for straight cylindrical channel and enables us to interpret the effects of the channel geometry and the electrostatic interaction. The correction ratio decreases with increasing of diverging angle, which implies that smaller zeta potential is generated for larger diverging angle. The increase of Debye length also reduces the correction ratio due to the overlapping of the Debye length inside of the channel. It is evident that as the diverging angle of the channel goes to nearly zero, the correction ratio converges to the previous results for straight cylindrical channel.

AB - The streaming potential is generated by the electrokinetic flow effect within the electrical double layer of a charged solid surface. Surface charge properties are commonly quantified in terms of the zeta potential obtained by computation with the Helmholtz-Smoluchowski (H-S) equation following experimental measurement of streaming potential. In order to estimate a rigorous zeta potential for cone-shaped microchannel, the correct H-S equation is derived by applying the Debye-Hückel approximation and the fluid velocity of diverging flow on the specified position. The present computation provides a correction ratio relative to the H-S equation for straight cylindrical channel and enables us to interpret the effects of the channel geometry and the electrostatic interaction. The correction ratio decreases with increasing of diverging angle, which implies that smaller zeta potential is generated for larger diverging angle. The increase of Debye length also reduces the correction ratio due to the overlapping of the Debye length inside of the channel. It is evident that as the diverging angle of the channel goes to nearly zero, the correction ratio converges to the previous results for straight cylindrical channel.

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U2 - 10.1016/S0021-9797(03)00576-9

DO - 10.1016/S0021-9797(03)00576-9

M3 - Article

VL - 266

SP - 120

EP - 126

JO - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

IS - 1

ER -