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Method Development for On-Site Air Quality Analysis and Design of Hydrogen Sensors for Orthopedic Applications

Smith, Michael E
http://orcid.org/0000-0002-4295-8917
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1583999801696302

Abstract Details

2020, PhD, University of Cincinnati, Arts and Sciences: Chemistry.
The work described in this dissertation is divided into two main sections, of which the first involved method development of a commercially available TD GC MS sensor for monitoring hazardous VOCs in air, while the second section detailed the development of a novel and visual hydrogen sensor for the target application of monitoring degradable Mg biomaterials in vivo. Motivation for research pertaining to the first section stems from the fact that many VOCs have been identified as highly toxic and/or carcinogenic and may cause short and long term human health effects as well as disrupt natural ecosystems. Additionally, increased emission of VOCs from anthropogenic sources and their subsequent effects on human health and ecosystems has drawn tremendous concern from a number of environmental safety agencies such as OSHA, NIOSH, and the EPA. In this work, a method was developed for a commercially available and field portable TD GC MS sensor for monitoring 10 selected VOCs in air via passive air sampling. It is proposed that the method described herein will be used for industrial hygiene exposure assessment and emergency response and recovery operations, which will enable rapid and on site assessments to determine compliance with worker exposure and public health standards. With respect to the second section of the dissertation, Mg and its alloys have the capability of outperforming traditionally used materials for orthopedic applications because they can act as load bearing implants that safely degrade when no longer needed. Novel combinations of materials capable of detecting hydrogen, a product of Mg corrosion, via visual color changes were studied with aim to develop visual sensors to non invasively monitor the in vivo corrosion of Mg implants in a clinical setting. Results from a solution based scope of reactivity study showed that the combination of resazurin with gold palladium nanoparticles (Au-Pd NPs) was best suited for the target application. Resazurin and Au Pd NPs were incorporated into thin Nafion™ films to construct visual hydrogen sensors. Orange to blue green color changes were observed for Nafion™ based hydrogen sensors upon exposure to hydrogen dissolved in water such that the UV-Vis absorption maximum corresponding to the blue green color of sensors was linearly proportional to the concentration of hydrogen. However, the color change associated with Nafion™ based hydrogen sensors was found to be reversible upon exposure to ambient oxygen, potentially limiting the sensitivity for monitoring degradable Mg implants. For these reasons, resazurin and Au Pd NPs were incorporated into thin hydrogel matrices to construct bandage like sensors that could undergo an irreversible color change via a redox reaction with hydrogen. The bandage like hydrogen sensors exhibited rapid, irreversible, and blue to pink color changes upon reaction with hydrogen at levels comparable to that detected from in vivo corrosion of subcutaneous Mg alloy implants in mice, thus making the bandage like hydrogen sensors potentially useful for non invasive monitoring of the in vivo corrosion of Mg implants in a clinical setting using a smart phone to quantify sensor color changes.
Peng Zhang, Ph.D. (Committee Chair)
William Heineman, Ph.D. (Committee Member)
James Mack, Ph.D. (Committee Member)
Laura Sagle, Ph.D. (Committee Member)
143 p.
Analytical Chemistry
TD-GC-MS; Passive air sampling; Hydrogen sensing; Magnesium biomaterials; Analytical chemistry; Optical sensing

Recommended Citations

Citations

  • Smith, M. E. (2020). Method Development for On-Site Air Quality Analysis and Design of Hydrogen Sensors for Orthopedic Applications [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1583999801696302

    APA Style (7th edition)

  • Smith, Michael. Method Development for On-Site Air Quality Analysis and Design of Hydrogen Sensors for Orthopedic Applications. 2020. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1583999801696302.

    MLA Style (8th edition)

  • Smith, Michael. "Method Development for On-Site Air Quality Analysis and Design of Hydrogen Sensors for Orthopedic Applications." Doctoral dissertation, University of Cincinnati, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1583999801696302

    Chicago Manual of Style (17th edition)

ucin1583999801696302
102
© 2020, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.