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dc.contributor.advisorSarathy, Mani
dc.contributor.authorChavarrio Cañas, Javier Eduardo
dc.date.accessioned2020-11-18T12:24:51Z
dc.date.available2020-11-18T12:24:51Z
dc.date.issued2020-11
dc.identifier.citationChavarrio Cañas, J. E. (2020). Theoretical Kinetic Study of Gas Phase Oxidation of Nicotine by Hydroxyl Radical. KAUST Research Repository. https://doi.org/10.25781/KAUST-60EK6
dc.identifier.doi10.25781/KAUST-60EK6
dc.identifier.urihttp://hdl.handle.net/10754/666016
dc.description.abstractCigarette smoke is suspected to cause diverse illnesses in smokers and people breathing second- and third-hand smoke. Although different studies have been done to elucidate the impact on health due to smoking, there is a lack of kinetic information regarding the degradation of nicotine under different environmental conditions. As a consequence, currently it is not possible to determine thoroughly the risk due to exposure to nicotine and the compounds derived from its decomposition. With the aim of contributing to clarify the different degradation paths followed by nicotine during and after the consumption of cigarettes, this work presents a theoretical study of the hydrogen atom abstraction reaction by hydroxyl radical at four sites in the nicotine molecule in a broad range of temperature, specifically be-tween 200-3000 K. The site-specific kinetic rate constants were computed by means of the multi-structural torsional variational transition state theory with small curvature tunneling contribution, performing ab initio calculations at the level M06-2X/aug-cc-pVQZ//M06-2X/cc-pVTZ. According to our computations, the dependence on temperature of the studied rate constants exhibited a non-Arrhenius fashion, with a minimum at 873 K. A negative temperature dependence was observed at temperatures lower than 873 K, indicating more prolonged exposure to nicotine in warmer environments. On the other hand, the opposite behavior was observed at higher temperatures; this non-Arrhenius be-havior results of interest in tobacco cigarette combustion, inducing different reaction mechanisms depending on the burning conditions of the different smoking devices. The results indicate that multi-structural and torsional anharmonicity is an im-portant factor in the computation of accurate rate constants, especially at high tem-peratures where the higher-energy conformers of the different species exert a larger influence. The anharmonicity factors suggest that disregarding the anharmonic de-viations leads to overestimation of the rate constant coefficients, by a factor between four and six. Our computed overall kinetic rate constant at 298 K exhibited very good agreement with the only experimental value meausred by Borduas et al. [1], af-fording certainty about our calculated site-specific rate constants, which are currently inaccessible to experiments. However, further experimental studies are necessary to validate our kinetic studies at other temperatures.
dc.language.isoen
dc.subjectNicotine degradation
dc.subjectKinetic study
dc.subjectAtmospheric oxidation
dc.titleTheoretical Kinetic Study of Gas Phase Oxidation of Nicotine by Hydroxyl Radical
dc.typeThesis
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.rights.embargodate2021-11-18
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberMishra, Himanshu
dc.contributor.committeememberCastaño, Pedro
thesis.degree.disciplineChemical Engineering
thesis.degree.nameMaster of Science
dc.rights.accessrightsAt the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis will become available to the public after the expiration of the embargo on 2021-11-18.
refterms.dateFOA2020-11-18T12:24:52Z
kaust.request.doiyes


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