TJ802 : Numerical and experimental study of the electrokinetic flow within the microchannel with porous membrane for preconcentration of charged particles using ion concentration polarization
Thesis > Central Library of Shahrood University > Mechanical Engineering > PhD > 2021
Authors:
[Author], Ali Jabari Moghadam[Supervisor]
Abstarct: In recent years, the passage of current through micro-nano ducts or porous membranes has been used to preconcentrate particles. The reason for this is to create ion selective behavior in the channel to allow only the desired ion to pass through the nanochannel or porous membrane. In this case, the ion concentration distribution is changed, causing two enriched and depleted regions in the microchannel; these changes are the basis of the ion concentration phenomenon. baxsed on this, the preconcentration of charged particles has been achieved, which has many applications in industrial, chemical and medical sciences. In this research, the numerical and experimental study of preconcentration of charged particle has been studied. Initially, in order to obtain effective parameters for the design of particle preconcentration, optimization baxsed on the response surface method (RSM) has been applied. The optimization results revealed that the effect of electrolyte concentration and the simultaneous effect of voltage and microchannel length on each other are the most important factors on particle preconcentration. The results of optimization also suggested an electric field in the range of 20-30 V/cm to find the maximum particle preconcentration for a given concentration of 1 mM. Then, according to the proposed electric field, microchannel design is performed. Experimental results showed that the applying different electric fields on the system lead to different patterns for the preconcentration of charged particles. Due to the application of different fields, the preconcentration of particles is classified as released along the microchannel, protruded, concentrated and without preconcentration. All the mentioned patterns are also confirmed by numerical simulation using COMSOL Multiphysics® software. Finally, through experimental and numerical analysis of the effect of electrolyte concentration on the enrichment factor, it was found that unlike the electric field, the concentration of electrolyte only affects the enrichment factor and has no effect on the pattern of preconcentrated particles. Findings of the present study can be used in biomedical applications for preconcentrating charged particles including protein and DNA for early detection of disease and to control the analytes in any` micro-nanofluidic systems.
Keywords:
#: Ion concentration polarization #Particle preconcentration #Response surface method #Numerical simulation #Experimental study Keeping place: Central Library of Shahrood University
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