P1AP.10 - pH Imaging of Ion Diffusion at Laminar Flow Interface and Estimation of Diffusion Coefficients

Event
17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
Chapter
P-1 - Applications of Chemical Sensors
Author(s)
K. Miyamoto, S. Naito, C. Werner, T. Yoshinobu - Department of Electronic Engineering, Tohoku University, Sendai (Japan), S. Uno - Department of Electrical and Electronic Engineering, Ritsumeikan University, Shiga (Japan)
Pages
454 - 455
DOI
10.5162/IMCS2018/P1AP.10
ISBN
978-3-9816876-9-9
Price
free

Abstract

A chemical imaging sensor, which is able to visualize the pH distribution, was combined with a Yshaped microfluidic channel. HCl was injected from one inlet and various solutions of chlorides with different cations were injected from the other inlet to form a laminar flow in the channel. The pH distribution was visualized at the laminar flow interface, where protons and cations were exchanged by diffusion. The apparent diffusion coefficient was calculated by fitting the change of pH distribution to the diffusion equation, which showed a clear dependence on the size of cations and fell between the diffusion coefficient of protons and that of cations. This result demonstrated the possibility of discriminating ions based on the measurement of their diffusivity by the chemical imaging sensor.

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