test Browse by Author Names Browse by Titles of Works Browse by Subjects of Works Browse by Issue Dates of Works
       

Advanced Search
Home   
 
Browse   
Communities
& Collections
  
Issue Date   
Author   
Title   
Subject   
 
Sign on to:   
Receive email
updates
  
My Account
authorized users
  
Edit Profile   
 
Help   
About T-Space   

T-Space at The University of Toronto Libraries >
School of Graduate Studies - Theses >
Doctoral >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1807/24814

Title: Integrated Droplet-based Microfluidics for Chemical Reactions and Processes
Authors: Li, Wei
Advisor: Kumacheva, Eugenia
Department: Chemistry
Keywords: microfluidics
microreactor
Issue Date: 30-Aug-2010
Abstract: This thesis describes a study of various aspects of chemical reactions conducted in microfluidic reactors. (i) In the first project, we proposed the application of the 'internal trigger' approach to multi-step microfluidic polymerization reactions conducted in droplets, namely, polyaddition and polycondensation. We hypothesized and experimentally established that heat generated in the exothermic free radical polymerization of an acrylate monomer triggers the polycondensation of the urethane oligomer. As a result, we synthesized monodispersed poly(acrylate/urethane) microparticles with an interpenetrating polymer network structure. (ii) In the second project, we developed a multiple modular microfluidic reactor with the purpose of increasing productivity in microfluidic synthesis. Compared to the productivity of the single microfluidic reactor < 1g/hr, we synthesized poly(N-isopropylacrylamide) particles at a productivity of approximately 50g/hr with a CV < 5%. We analyzed and addressed several challenges of this process, such as the fidelity in the fabrication of microfluidic reactors, crosstalk between individual reactors sharing a common liquid supply, and coalescence of droplets. (iii) We developed an integrated microfluidic reactor comprising four parallel individual reactors to study the effect of geometry and surface energy of the microchannels on the emulsification process. We spontaneously generated droplets with different volumes by integrating individual droplet generators in parallel with varying geometry. This approach is important in studies of the effect of droplet surface and volume on chemical reactions, and in the studies of diffusion-controlled processes. (iv) We conducted a microfluidic study of the reversible binding of CO2 to secondary amines in the process that mediates solvent polarity switch. We studied reaction rates and CO2 uptake by generating plugs of gaseous a CO2 and monitoring the change in their dimensions. We also demonstrated fast screening of reaction conditions, as well as the ability to reverse the reaction in situ.
URI: http://hdl.handle.net/1807/24814
Appears in Collections:Doctoral
Department of Chemistry - Doctoral theses

Files in This Item:

File Description SizeFormat
Li_Wei_201006_PhD_Thesis.pdf7.24 MBAdobe PDF
View/Open

Items in T-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

uoft