Chemistry at liquid-liquid interfaces: con- and counter-current extraction and biologically active membranes in microchannels

Viernes, Neil Oliver

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https://hdl.handle.net/2142/88122 Copy

Description

Title

Chemistry at liquid-liquid interfaces: con- and counter-current extraction and biologically active membranes in microchannels

Author(s)

Viernes, Neil Oliver

Issue Date

2015-07-23

Director of Research (if dissertation) or Advisor (if thesis)

Moore, Jeffrey S.

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Microfluidics
• Membrane

Abstract

Surface modification of microchannels with a photo-reactive self-assembled monolayer (SAM) allows for the stable photo-patterning of liquid-air interfaces within the microchannel. It is also found that these hydrophobic/hydrophilic interfaces allow for stable interfaces between immiscible fluids. Chemistry can be conducted at these interfaces. Reversed-micelle extraction of metal ions is studied. Traditionally, fluid flow of immiscible liquids is not stable and requires controlled microchannel geometries and flow rates. The stability of the liquid-liquid interface allows for exploration in varying flow profiles within the microchannel that could not be previously studied. In particular, the flow profile in which one phase is left stationary, con- and counter-current flow. It is found that reversed-micelle extraction does not behave like typical diffusion based extraction. What is observed is an unusual perturbation at the liquid-liquid interface during the extraction that leads to turbulent flow in the microchannel. This turbulent flow differs based on the type of fluid flow in the microchannel. The ability to create stable liquid-liquid interfaces allows for the formation of membranes within the microchannel via interfacial polymerization. The stability of liquid-liquid interfaces allows for membrane formation via interfacial polymerization. Polyamide membranes are created incorporating amino acid residues. The selection of the amino acid sequence allows for the ability to create biologically active membranes that can potentially be used as biological sensors. Biologically active membranes that are reactive to chymotrypsin are synthesized and studied. It is found that these polyamide membranes can be synthesized within the microchannel and have shown reactivity toward chymotrypsin. The result of the reaction with chymotrypsin leads to a breakdown in the membranes porosity that can be visualized as a change in spontaneous fluid flow or it can lead to total dissolution of the membrane itself.

Graduation Semester

2015-8

Type of Resource

text

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http://hdl.handle.net/2142/88122

Copyright and License Information

Copyright 2015 Neil O.L. Viernes

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