No abstract

Nickel-based metallic foams are commonly used in electrochemical energy storage devices (rechargeable batteries) as both current collectors and active mass support. These materials attract attention as tunable electrode materials because they are available in a range of chemical compositions, pore structures, pore sizes, and densities. This contribution presents structural, chemical, and electrochemical characterization of Ni-based metallic foams. Several materials and surface science techniques (transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), focused ion beam (FIB), and X-ray photoelectron spectroscopy (XPS)) and electrochemical methods (cyclic voltammetry (CV)) are used to examine the micro-, meso-, and nanoscopic structural characteristics, surface morphology, and surface-chemical composition of these materials. XPS combined with Ar-ion etching is employed to analyze the surface and near-surface chemical composition of the foams. The specific and electrochemically active surface areas (As, Aecsa) are determined using CV. Though the foams exhibit structural robustness typical of bulk materials, they have large As, in the range of 200-600 cm(2) g(-1). In addition, they are dual-porosity materials and possess both macro- and mesopores.

Dysregulated metal ions are hypothesized to play a role in the aggregation of the amyloid-β (Aβ) peptide, leading to Alzheimer's disease (AD) pathology. In addition to direct effects on Aβ aggregation, both Cu and Fe can catalyze the generation of reactive oxygen species (ROS), possibly contributing to significant neuronal toxicity. Therefore, disruption of metal-Aβ interactions has become a viable strategy for AD therapeutic development. Herein, we report a new series of dual-function triazole-pyridine ligands [4-(2-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)ethyl)morpholine (L1), 3-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)propan-1-ol (L2), 2-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)acetic acid (L3), and 5-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)pentan-1-amine (L4)] that interact with the Aβ peptide and modulate its aggregation in vitro. Metal chelation and Aβ interaction properties of these molecules were studied by UV-vis, NMR spectroscopy and X-ray crystallography. In addition, turbidity and transmission electron microscopy (TEM) were employed to determine the anti-aggregation properties of L1-L4. All compounds demonstrated an ability to limit metal-induced Aβ aggregation. Overall, our studies suggest the utility of the triazole-pyridine framework in the development of chemical reagents toward inhibitors for metal-triggered Aβ aggregation.

A series of cobalt salen complexes, where salen represents an N2O2 bis-Schiff-base bis-phenolate framework, are prepared, characterised and investigated for reversible-termination organometallic mediated radical polymerisation (RT-OMRP). The salen ligands contain a cyclohexane diimine bridge and systematically altered para-substituted phenoxide moieties as a method to examine the electronic impact of the ligand on complex structure and reactivity. The complexes are characterised by single crystal X-ray diffraction, cyclic voltammetry, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy and computational methods. Structural studies all support a tailorable metal centre reactivity altered by the electron-donating ability of the salen ligand. RT-OMRP of styrene, methyl methacrylate and vinyl acetate is reported and suggests that cobalt-carbon bond strength varies with the ligand substitution. Competing β-hydrogen abstraction affords long-chain olefin-terminated polymer chains and well controlled vinyl acetate polymerisations, contrasting with the lower temperature associative exchange mechanism of degenerative transfer OMRP.

One of the hallmarks of Alzheimer's disease (AD) in the brain are amyloid- (A) plaques, and metal ions such as copper(II) and zinc(II) have been shown to play a role in the aggregation and toxicity of the A peptide, the major constituent of these