Repository logo

Theses and Dissertations

Permanent URI for this collection

https://hdl.handle.net/10217/100368

Browse

Browsing Theses and Dissertations by Author "Ackerson, Chris J., committee member"

Now showing 1 - 4 of 4
  • Thumbnail Image
    ItemOpen Access
    Development of a multidisciplinary toolkit for the colloidal nanoparticle synthesis of copper selenophosphate, Cu3PSe4, a promising material for photovoltaics
    (Colorado State University. Libraries, 2021) Lee, Jennifer M., author; Prieto, Amy L., advisor; Ackerson, Chris J., committee member; Henry, Chuck S., committee member; Buchanan, Kristen S., committee member
    To view the abstract, please see the full text of the document.
  • Thumbnail Image
    ItemOpen Access
    Development of biomass-derived furanic monomers for biorenewable polyesters and polyurethanes
    (Colorado State University. Libraries, 2019) Wilson, Jedediah Forrest, author; Chen, Eugene Y.-X., advisor; Reynolds, Melissa M., committee member; Ackerson, Chris J., committee member; Radford, Donald W., committee member; Crans, Debbie C., committee member
    Development of Biomass-Derived Furanic Monomers for Biorenewable Polyesters and Polyurethanes This dissertation describes the development of difuranic diol monomers through the N-heterocyclic carbene (NHC) catalyzed cross-coupling of the biomass-derived platform chemicals, 5-hydroxymethylfurfural (HMF) and furfural (FF), and their subsequent utilization in the synthesis of renewable polyesters and polyurethanes with tunable thermal and mechanical properties through the use of soft and rigid co-monomers. The resulting polymers can undergo reversible cross-linking with bis-maleimide cross-linkers through the thermally reversible Diels-Alder reaction involving both the internal and pendent furan rings. The ability to construct a thermally reversible cross-linked network, coupled with formation of a significant amount (up to 34%) of stable carbonaceous materials when heating the polymers to 700 °C, demonstrates some promising features of this class of new difuranic polymers. To address the need to enhance the molecular weight of the current furan-based polymers produced by the step-growth polycondensation process, alternative monomer structures have been designed to adopt the chain-growth mechanism. The first such alternative monomer belongs to a class of furan-derived lactones as candidates for ring-opening polymerization (ROP), which have been shown to produce high molecular weight polyesters because they follow the chain-growth mechanism. Two synthetic routes have been explored to produce such lactone monomers, and their polymerization behavior has been subsequently examined. The second such alternative is centered on a multifunctional furan acrylate monomer, methacrylate furan aldehyde (MFA). The studies tested a hypothesis that auto-tandem or cascading reaction involving the aldehyde functionality in MFA would undergo a benzoin condensation, then the consequent diacrylate would have the appropriate functionality for NHC catalyzed tail-to-tail coupling resulting in a proton transfer polymerization (HTP). It was found that the benzoin condensation was successful but an oxidation occurred at the α-hydroxy of the furoin diacrylate resulting in a highly electrophilic diketone furil diacrylate. Exploration of the coupling mechanism suggests that the enolate acts as a base catalyzing the oxidation. Through careful analysis of the adducts formed when the NHC was reacted with the furil diacrylate showed that the NHC had strong affinity for the diketone moiety thus blocking the HTP pathway. Overall, this work added significantly to our understanding of furans as monomers, NHC catalysis in furan monomer synthesis as well as polymerizations, and enhanced our ability to control thermal and mechanical properties of furan containing polymers.
  • Thumbnail Image
    ItemEmbargo
    Synthesis and discovery of mixed-anion nitride materials
    (Colorado State University. Libraries, 2023) Storck, Emily N., author; Neilson, James R., advisor; Ackerson, Chris J., committee member; Ma, Kaka, committee member
    The ability to synthesize heteroanionic (or mixed-anion) materials is an important area in solid-state chemistry research. Mixed-anion compounds offer the potential to provide more desirable functionality compared to single-anion systems. However, mixed-anion systems are underexplored compared to single-anions. This is especially true for nitride materials when compared to oxides, because nitrides are difficult to make. The ease of making most oxides is due to the reactivity of oxygen and the thermodynamic stability of metal oxides, whereas the strong triple bond of N2 leads to its low reactivity and therefore difficulty in making nitrides and oxynitrides. Therefore, improved synthetic routes to produce these mixed-anion compounds are needed to unlock the potential of this underexplored phase space. This thesis describes the use of solid-state metathesis reactions to produce heteroanionic ZrNCl through reaction between AyNCl (A = Zn, Mg, or Li) precursors and ZrCl4. This thesis also highlights the use of flux reactions in attempts to synthesize new oxynitride materials based on the hypothesis that alkali halide salts have the ability to solublize nitrogen and raise its chemical potential relative to the chemical potential of nitrogen in traditional solid-state reactions to produce nitrides and oxynitrides, allowing for incorporation into products to form an oxynitride material. Here, a eutectic flux mix, LiCl-KCl, was used in the reaction between V2O3 and Li3N to synthesize vanadium containing compounds along with preliminary experiments to ascertain their stiochiometry.
  • Thumbnail Image
    ItemOpen Access
    Synthesis of fluoromodified carbon rich electron acceptors and exploration of their structural, electronic, and device properties
    (Colorado State University. Libraries, 2020) DeWeerd, Nicholas J., author; Strauss, Steven H., advisor; Shores, Matthew P., committee member; Ackerson, Chris J., committee member; McCullagh, Martin J., committee member; Gelfand, Martin P., committee member
    The electronic and structural characterization of fluoro-modified carbon-rich compounds is critical to the successful implementation of these materials by physicists, biochemists, materials scientists, medicinal chemists, and most significantly for this work, organic electronics chemists. By adding powerful electron-withdrawing groups, the electron acceptor and solid-state structural properties of carbon rich substrates such as polyaromatic hydrocarbons (PAHs) and fullerenes can be improved, making these derivatives attractive semiconductor materials for organic electronics applications. This work will discuss research which has focused on expanding the library of electron acceptor compounds, elucidating the electronic and structural properties of those compounds, and exploring their physicochemical properties, focusing on properties that are important for the performance of organic electronic devices. This was accomplished by exploring reaction conditions which had not been previously reported at pressures and temperatures exceeding the operational limits of conventional reactors, developing purification methods that allow for chromatographic separation of constitutional isomers, and structural characterization of those purified materials by mass spectrometry, NMR, and most importantly X-ray crystallography. As a complement to this research, the stability of organic electronic active layers was studied to better understand how organic semiconductor active layer's degradation affects device performance over time and to better inform which active layer material properties should be pursued. Based on those findings and literature precedent, one family of compounds, C60 and C70 fauxhawk fullerenes, found to have favorable characteristics were then utilized in OFET devices as n-type semiconductors resulting in record-setting charge carrier mobilities.