Browsing by Subject "copper"

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    Atomistic modeling of resistivity evolution of copper nanoparticle in intense pulsed light sintering process
    (Elsevier, 2019-02) Meng, Lingbin; Zhang, Yi; Yang, Xuehui; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and Technology
    In this work, the intense pulsed light (IPL) sintering process of copper nanoparticle ink is simulated using molecular dynamics (MD) method. First, the neck size growth between the two copper nanoparticles during the IPL sintering process is computed. The resultant electrical resistivity is then calculated by substituting the neck size into the Reimann-Weber formula. Overall, a rapid decrease of electric resistivity is observed in the beginning of the sintering, which is caused by quick neck size growth, followed by a gradually decrease of resistivity. In addition, the correlation of the simulated temperature dependent resistivity is similar to that of the experimentally measured resistivity. The MD model is an effective tool for designers to optimize the IPL sintering process.
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    Design, Synthesis, and Structure of Copper Dithione Complexes: Redox‐Dependent Charge Transfer
    (Wiley, 2019-12) Colston, Kyle J.; Dille, Sara A.; Mogesa, Benjamin; Astashkin, Andrei V.; Brant, Jacilynn A.; Zeller, Matthias; Basu, Partha; Chemistry and Chemical Biology, School of Science
    Redox‐active ligands impart versatility in transition metal complexes, which are attractive for photosensitizers, dye sensitized solar cells, photothermal therapy, etc. Dithiolene (Dt) ligands can transition between fully reduced and fully oxidized states. Herein, we report the syntheses, characterization, crystal structures and electronic properties of four [Cu(R2Dt0)2]+/2+ (R = Me, iPr) complexes, [Cu(iPr2Dt0)2][PF6] (1a), [Cu(iPr2Dt0)2][PF6]2 (1b), and [Cu(Me2Dt0)2][PF6] (2a), [Cu(Me2Dt0)2][PF6]2 (2b), where iPr2Dt0 = N,N′‐diisopropyl‐1,2‐piperazine dithione and Me2Dt0 = N,N′‐dimethyl‐1,2‐piperazine dithione. In addition, the molecular structure of [Cu(iPr2Dt0)2][BF4]2(1c) is also reported. Complexes 1a and 2a crystallized in the triclinic, P1 space group, and 1c crystallized in the monoclinic crystal system, space group C2/c. The single‐crystal X‐ray diffraction measurements show that the Cu(I) complexes have a distorted tetrahedral geometry, whereas the Cu(II) complex exhibits a true square‐planar geometry. Cu(I) complexes exhibit a low energy charge‐transfer band (450–650 nm), which are not observed in Cu(II) complexes. Electrochemical studies of these complexes show both ligand‐ and metal‐based redox couples.
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    The role of SMF 1, SMF-2, SMF-3 in metal-induced whole animal vulnerability and dopamine neuron degeneration in Caenorhabditis elegans
    (2012-12-04) LeVora, Jennifer K.; Nass, Richard M.; Nicol, Grant D.; Hingtgen, Cynthia M., 1966-
    The etiology of many neurodegenerative diseases is unknown, but a number of studies indicate that a combination of both genetic and environmental factors contribute to the progression of disease. Exposure to environmental metals, such as Mn2+, Fe2+, Cu2+, and Al3+, has been shown to increase cell death that is characteristic of neurodegenerative disorders such as AD, PD, Wilson’s disease and Menkes disease. These metals are important in numerous biological processes in the brain and their homeostasis is regulated through multiple mechanisms of transport, storage, and secretion. The vertebrate divalent metal transporter-1 (DMT-1) has been implicated in transport and homeostasis of these divalent cations. In these studies I utilize Caenorhabditis elegans (C. elegans) to show that long term exposure to Mn2+ decreases animal viability in a dose-dependent manner, and I demonstrate that C. elegans homologues to DMT-1, SMF-1, SMF-2, and SMF-3, play specific roles in divalent metal ion-induced DA neurodegeneration. I show that SMF-1 contributes to Fe2+-induced DA neuron degeneration, SMF-3 contributes to Al3+-induced DA neuron degeneration, and both SMF-2 and DAT-1 contribute to Cu2+-induced DA neuron cell death. These studies utilize C. elegans as a powerful model to characterize molecules and pathways involved in metal toxicity and metal-induced DA neuron degeneration.