title: Numerical modeling of surface reaction kinetics in electrokinetically actuated microfluidic devices.
abstract: We outline a comprehensive numerical procedure for modeling of species transport and surface reaction kinetics in electrokinetically actuated microfluidic devices of rectangular cross section. Our results confirm the findings of previous simplified approaches that a concentration wave is created for sufficiently long microreactors. An analytical solution, developed for the wave propagation speed, shows that, when normalizing with the fluid mean velocity, it becomes a function of three parameters comprising the channel aspect ratio, the relative adsorption capacity, and the kinetic equilibrium constant. Our studies also reveal that the reactor geometry idealized as a slit, instead of a rectangular shape, gives rise to the underestimation of the saturation time. The extent of this underestimation increases by increasing the Damkohler number or decreasing the dimensionless Debye-Hückel parameter. Moreover, increasing the values of the Damkohler number, the dimensionless Debye-Hückel parameter, the relative adsorption capacity, and the velocity scale ratio results in lower saturation times.
authors: Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, P.O. Box 11155-9567, Tehran, Iran. Electronic address: armansadeghi@mech.sharif.edu.
authors: Arman
authors: A
authors: Sadeghi
authors: Department of Chemical Engineering, Isfahan University of Technology, Isfahan, Iran. Electronic address: y.amini@ce.iut.ac.ir.
authors: Younes
authors: Y
authors: Amini
authors: Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering, Sharif University of Technology, P.O. Box 11155-9567, Tehran, Iran. Electronic address: saman@sharif.edu.
authors: Mohammad Hassan
authors: MH
authors: Saidi
authors: Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721302, India. Electronic address: suman@mech.iitkgp.ernet.in.
authors: Suman
authors: S
authors: Chakraborty
keywords: Electroosmotic flow; Mass transport; Microfluidics; Numerical modeling; Surface reaction