Date of Award

Summer 7-2016

Document Type

Thesis

Degree Name

Master of Science in Chemical Engineering (MSChE)

Department

Chemical Engineering

First Advisor

Kimberly Henworth

Second Advisor

Adam Nolte

Third Advisor

Daniel Morris

Abstract

Particulate transport in microfluidic channels is difficult due to confined geometries and low flow rates, which promote solids settling. To re-entrain these solids, the detachment behavior of closely-fitting particles from microchannel walls must be understood. Experiments were completed to examine the effects of particle size and material interactions on particle detachment velocity. Studies were conducted for various sizes of glass and poly(methyl methacrylate), PMMA, spheres in glass and poly(dimethyl siloxane), PDMS, microfluidic channels. In addition, an inexpensive method to produce monodisperse PMMA microparticles was developed. To analyze the effect of material interactions, the work of adhesion between the particle and the channel wall was calculated. The fluid velocity required to detach a particle was found to be relatively constant until the particle-to-channel diameter ratio approached approximately 50%, after which detachment velocity decreased with increasing particle size. Particles in a glass microchannel experienced significantly more adhesion than those in PDMS channels.

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