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Design and Implementation of QCM Virtual Sensing Schemes for Analyses of Volatile Organic Compounds

Sensor arrays have evolved as powerful approaches for providing detection and discrimination of volatile organic compounds (VOCs) as required across numerous analytical applications. Such systems typically comprise a number of cross reactive sensor elements, which generate analyte specific response patterns upon exposure to VOCs, and are known as multisensor arrays. When evaluated using statistical methods, these response patterns facilitate classification of VOCs. As an alternative, a single dynamically operated sensor could also be used to generate analyte specific response patterns. This approach is known as a virtual sensor array (VSA) and can exhibit significant advantages when compared to MSAs. Some advantages include lower power consumption, sensor drift, material cost, and experimental preparatory time. Furthermore, several dynamically operated sensors could be used in tandem (using the MSA and VSA scheme in a complementary fashion) to fabricate virtual multisensor arrays (V-MSAs). Such systems would exhibit greater data density than either the MSA or VSA, and are promising for samples that are particularly challenging to discriminate.
Among the various systems utilized for VOC discrimination, sorption based systems hold considerable promise because they are simple and inexpensive yet highly effective. This dissertation is focused on the development of array sensing schemes using ionic liquids (ILs), a group of uniform materials based on organic salts (GUMBOS), and binary blends of either IL or GUMBOS with polymer as recognition elements and the quartz crystal microbalance (QCM) as the transducer. Towards this end, ILs, which are defined as organic salts with melting points below 100 °C, and group of uniform materials based on organic salts (GUMBOS) which extend the melting range of ILs to 250 °C to encompass similar solid phase salts, were used to design the first examples of QCM based VSAs, and V-MSAs, for pure VOC and complex mixture analyses. Furthermore binary blends of organic salts and polymer were used to fabricate the first VSA with the capability to identify and approximate molecular weight of pure VOCs. By and large, the studies presented here demonstrate the excellent potential of these materials and techniques for advancement of vapor phase measurement science.

Identiferoai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-06222016-064950
Date07 July 2016
CreatorsSpeller, Nicholas Colby
ContributorsIsiah M. Warner, Samuel D. Gilman, George Stanley, Huangen Ding
PublisherLSU
Source SetsLouisiana State University
LanguageEnglish
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lsu.edu/docs/available/etd-06222016-064950/
Rightsrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.

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