Elaboration of copper-tin alloys coatings : effects of glycine

International audienc

Adsorption of gelatin during electrodeposition of copper and tin-copper alloys from acid sulfate electrolyte

International audienceAn acid Cu–Sn deposition bath was developed, and copper and copper–tin coatings were electrodeposited on polycrystalline platinum. The effect of gelatin on copper and copper–tin electrodeposition from acid sulfate solutions has been investigated by a variety of electrochemical methods (voltammetric studies and electrochemical quartz crystal microbalance) as well as by morphologic technique (scanning electron microscopy). The electrochemical results have shown that the overpotential is required when gelatin is added, indicating the presence of interaction between the additive and the coating. From the results of X-ray photoelectron spectroscopy, PM-IRRAS and cyclic voltammetry, gelatin was found to react with metal ions and platinum substrate. Adsorption of gelatin on the coating and platinum substrate is shown. Gelatin adsorption seemed to inhibit the initial nucleation of the copper and copper–tin electrodeposition, allowing homogeneous and smaller crystallites. Addition of gelatin was found to have an effect on reducing copper–tin alloys. The presence of gelatin impacts the crystal size and morphology of Cu–Sn deposits

Influence of organic additives on the initial stages of copper electrodeposition

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Nasal neuron PET imaging quantifies neuron generation and degeneration

Olfactory dysfunction is broadly associated with neurodevelopmental and neurodegenerative diseases and predicts increased mortality rates in healthy individuals. Conventional measurements of olfactory health assess odor processing pathways within the brain and provide a limited understanding of primary odor detection. Quantification of the olfactory sensory neurons (OSNs), which detect odors within the nasal cavity, would provide insight into the etiology of olfactory dysfunction associated with disease and mortality. Notably, OSNs are continually replenished by adult neurogenesis in mammals, including humans, so OSN measurements are primed to provide specialized insights into neurological disease. Here, we have evaluated a PET radiotracer, [11C]GV1-57, that specifically binds mature OSNs and quantifies the mature OSN population in vivo. [11C]GV1-57 monitored native OSN population dynamics in rodents, detecting OSN generation during postnatal development and aging-associated neurodegeneration. [11C]GV1-57 additionally measured rates of neuron regeneration after acute injury and early-stage OSN deficits in a rodent tauopathy model of neurodegenerative disease. Preliminary assessment in nonhuman primates suggested maintained uptake and saturable binding of [18F]GV1-57 in primate nasal epithelium, supporting its translational potential. Future applications for GV1-57 include monitoring additional diseases or conditions associated with olfactory dysregulation, including cognitive decline, as well as monitoring effects of neuroregenerative or neuroprotective therapeutics

Effects of natural organic matter and ionic species on membrane surface charge

The surface charges of clean and natural organic matter (NOM) adsorbed membrane surfaces of two different types of membranes (a UF and a NF membrane composed of the same material but having different pore sizes) were investigated Concentrated NOM and its fractionated constituents were used as adsorbate and interacting macromolecules near the membrane surface The potential and the acidity of membranes were measured using electrophoresis and potentiometric titration methods respectively from the perspective of charge characterization along with demonstration of ionic strength effects The membrane surface was also characterized with attenuated total refractive Fourier transform infrared spectra to determine intrinsic functional groups and those changes before and after NOM adsorption As a comparative study for the electrokinetic property of membrane the potentials for both examined polymeric membranes were determined by the electrophoresis and the streaming potential measurement methods as functions of ionic strength and the pH of measuring solution Selectivity tests were performed to decide the relative importance of charge valence of cation in terms of the surface charge of membrane It was demonstrated that divalent cations (Ca2+ Mg2+) increase zeta potentials relatively compared to monovalent cations (Na+ K+) because divalent cations have a greater potential in approaching membrane surfaces (i e inside the Stern layer) Thus divalent cations can provide a greater double layer compaction and when near the shear plane (available for both the potential measurement methods) exist to a lesser extent than monovalent cationsclose10311