Microfluidics for environmental analysis
| dc.contributor.author | Gerold, Chase T., author | |
| dc.contributor.author | Henry, Charles S., advisor | |
| dc.contributor.author | Krummel, Amber, committee member | |
| dc.contributor.author | Levinger, Nancy, committee member | |
| dc.contributor.author | Finke, Richard, committee member | |
| dc.contributor.author | Dandy, David, committee member | |
| dc.date.accessioned | 2018-09-10T20:04:55Z | |
| dc.date.available | 2018-09-10T20:04:55Z | |
| dc.date.issued | 2018 | |
| dc.description.abstract | During my graduate dissertation work I designed and utilized microfluidic devices to study, model, and assess environmental systems. Investigation of environmental systems is important for areas of industry, agriculture, and human health. While effective and well-established, traditional methods to perform environmental assessment typically involve instrumentation that is expensive and has limited portability. Because of this, analysis of environmental systems can have considerable financial burden and be limited to laboratory settings. To overcome the limitations of traditional methods researchers have turned to microfluidic devices to perform environmental analyses. Microfluidics function as a versatile, inexpensive, and rapidly prototyped analytical tool that can achieve analysis in field setting with limited infrastructure; furthermore, microfluidic devices can also be used to study fundamental chemistry or model complex environmental systems. Given the advantages of microfluidic devices, the research presented herein was accomplished using this alternative to traditional instrumentation. The research projects described in this dissertation involve: 1) the study of fundamental chemistry associated with surfactant surface fouling facilitated by divalent metal cations; 2) the creation of a microfluidic device to study fluid interactions within an oil reservoir; and 3) the fabrication of a paper-based microfluidic to selectively quantify K+ in complex samples. The first research topic discussed involves observation of dynamic evidence that supports the hypothesized cation bridging phenomenon. Experimental results were acquired by pairing traditional microfluidics with the current monitoring method to observe relative changes to a charged surface's zeta potential. Divalent metal cations were found to increase surfactant adsorption, and cations of increasing charge density were found to have a greater effect on surface charge. Analysis of the experimental data further supports theoretical cation bridging models and expands on knowledge relating to the mechanism by which surfactant adsorption occurs. This work was published in the ACS journal Langmuir (2018, 34 (4), pp 1550–1556). The second project discussed herein focuses on the development of the microfluidic Flow On Rock Device (FORD) that was designed to study fluid interactions within complex media. The FORD was designed to be an alternative to existing fluid modeling methods and microfluidic devices that test oil recovery strategies. Fabrication of the FORD was accomplished by incorporating real reservoir rock core samples into the device. The novelty of this device is due to the simplicity and accuracy by which the physical and chemical characteristics are represented. This project has been accepted for publication pending minor revisions in Microfluidics and Nanofluidics. The final project discussed the creation of the first non-electrochemical microfluidic paper-based analytical device (µPAD) capable of quantitatively measuring alkali or alkaline earth metals using K+ as a model analyte. This device was fabricated by combining distance-based analytical quantification in µPADs with optode nanosensors. Experimental results were obtained using the naked eye without the requirement of a power source or external hardware. The resulting distance-based µPAD showed high selectivity and the capacity to quantify K+ in real undiluted human serum samples. This work has been published in the ACS journal Analytical Chemistry (2018, 90 (7), pp 4894–4900). The research projects briefly described above and thoroughly discussed later within this dissertation were made possible by the utilization of microfluidic devices. These projects investigated various aspects of environmental chemistry without the use of traditional instrumentation or methods. The experimental results that were obtained further the fundamental understanding of surfactant adsorption, provide an inexpensive and accurate model to observe fluid interactions within reservoir rock material, and allow for the selective quantification of K+ in a paper-based device without the use of a power source. The funding for each of these projects was supplied by BP plc and Global Good, as is mentioned accordingly within this dissertation. | |
| dc.format.medium | born digital | |
| dc.format.medium | doctoral dissertations | |
| dc.identifier | Gerold_colostate_0053A_14975.pdf | |
| dc.identifier.uri | https://hdl.handle.net/10217/191385 | |
| dc.language | English | |
| dc.language.iso | eng | |
| dc.publisher | Colorado State University. Libraries | |
| dc.relation.ispartof | 2000-2019 | |
| dc.rights | Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright. | |
| dc.subject | metal quantification | |
| dc.subject | oil recovery | |
| dc.subject | environmental | |
| dc.subject | paper-based | |
| dc.subject | microfluidics | |
| dc.title | Microfluidics for environmental analysis | |
| dc.type | Text | |
| dcterms.rights.dpla | This Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). | |
| thesis.degree.discipline | Chemistry | |
| thesis.degree.grantor | Colorado State University | |
| thesis.degree.level | Doctoral | |
| thesis.degree.name | Doctor of Philosophy (Ph.D.) |
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