Effect of fluorescent dye on zeta potential in electroosomotic flow

Fluorescent dyes are widely used in the area of microfluidic studies. However, few studies have been conducted to determine whether these fluorescent dyes affect the zeta potential and the electroosomotic flow (EOF) of the fluids used in experiments. This project aims to investigate the effect of f...

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Main Author: Wong, Jonathan Tze Hou
Other Authors: Lam Yee Cheong
Format: Final Year Project
Language:English
Published: 2014
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Online Access:http://hdl.handle.net/10356/60155
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-601552023-03-04T18:33:07Z Effect of fluorescent dye on zeta potential in electroosomotic flow Wong, Jonathan Tze Hou Lam Yee Cheong School of Mechanical and Aerospace Engineering DRNTU::Engineering::Mechanical engineering::Fluid mechanics Fluorescent dyes are widely used in the area of microfluidic studies. However, few studies have been conducted to determine whether these fluorescent dyes affect the zeta potential and the electroosomotic flow (EOF) of the fluids used in experiments. This project aims to investigate the effect of fluorescent dyes on zeta potential in EOF, which is induced by an electric field. Sodium bicarbonate (NaHCO3) is used as the buffer solution in this project as it is stable in all the substrates used; providing a good baseline on which the behaviors of the fluorescent dyes can be analysed. The dyes used are disodium fluorescein (Fl), Rhodamine B (RhB) and Rhodamine 6G (Rh6G). Current monitoring method was utilized to measure the time taken for the fluid to be transported through straight microchannels made from three different materials, namely glass, polydimethylsiloxane (PDMS) and polyurethane (PU). Linear curve fitting is performed to determine the time taken for the fluid to be transported through the channel from the current-time plot. Subsequently, the zeta potential can be determined. Finally, statistical tests are conducted to examine the effect of fluorescent dyes on zeta potential of various microchannels. From the experimental result, it can be observed that Fl dye which is a negatively charged dye increases the zeta potential for flow in PU microchannels. This phenomenon is potentially useful and can be exploited to increase the flow velocity in PU microchannels. RhB which is a neutral dye has no effect on the zeta potential of a fluid when it is added to the buffer solution. Rh6G which is a positive dye does not support any EOF in glass, PDMS and PU microchannels. This effect is potentially useful to suppress EOF in certain applications. For example, during the measurement of ion mobility, EOF is typically not desirable and should be suppressed. Bachelor of Engineering (Mechanical Engineering) 2014-05-22T07:59:48Z 2014-05-22T07:59:48Z 2014 2014 Final Year Project (FYP) http://hdl.handle.net/10356/60155 en Nanyang Technological University 38 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Mechanical engineering::Fluid mechanics
spellingShingle DRNTU::Engineering::Mechanical engineering::Fluid mechanics
Wong, Jonathan Tze Hou
Effect of fluorescent dye on zeta potential in electroosomotic flow
description Fluorescent dyes are widely used in the area of microfluidic studies. However, few studies have been conducted to determine whether these fluorescent dyes affect the zeta potential and the electroosomotic flow (EOF) of the fluids used in experiments. This project aims to investigate the effect of fluorescent dyes on zeta potential in EOF, which is induced by an electric field. Sodium bicarbonate (NaHCO3) is used as the buffer solution in this project as it is stable in all the substrates used; providing a good baseline on which the behaviors of the fluorescent dyes can be analysed. The dyes used are disodium fluorescein (Fl), Rhodamine B (RhB) and Rhodamine 6G (Rh6G). Current monitoring method was utilized to measure the time taken for the fluid to be transported through straight microchannels made from three different materials, namely glass, polydimethylsiloxane (PDMS) and polyurethane (PU). Linear curve fitting is performed to determine the time taken for the fluid to be transported through the channel from the current-time plot. Subsequently, the zeta potential can be determined. Finally, statistical tests are conducted to examine the effect of fluorescent dyes on zeta potential of various microchannels. From the experimental result, it can be observed that Fl dye which is a negatively charged dye increases the zeta potential for flow in PU microchannels. This phenomenon is potentially useful and can be exploited to increase the flow velocity in PU microchannels. RhB which is a neutral dye has no effect on the zeta potential of a fluid when it is added to the buffer solution. Rh6G which is a positive dye does not support any EOF in glass, PDMS and PU microchannels. This effect is potentially useful to suppress EOF in certain applications. For example, during the measurement of ion mobility, EOF is typically not desirable and should be suppressed.
author2 Lam Yee Cheong
author_facet Lam Yee Cheong
Wong, Jonathan Tze Hou
format Final Year Project
author Wong, Jonathan Tze Hou
author_sort Wong, Jonathan Tze Hou
title Effect of fluorescent dye on zeta potential in electroosomotic flow
title_short Effect of fluorescent dye on zeta potential in electroosomotic flow
title_full Effect of fluorescent dye on zeta potential in electroosomotic flow
title_fullStr Effect of fluorescent dye on zeta potential in electroosomotic flow
title_full_unstemmed Effect of fluorescent dye on zeta potential in electroosomotic flow
title_sort effect of fluorescent dye on zeta potential in electroosomotic flow
publishDate 2014
url http://hdl.handle.net/10356/60155
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