Search

Impressed current cathodic protection systems are used in combination with organic coatings to prevent corrosion of hulls. The reaction species which are formed in the proximity of the anodes, like chlorinated compounds and acidity, can stress the antifouling paints of the protective coating system. A 3 × 3 matrix was defined to drive the tests aiming to investigate the behavior of novel biocide-free foul release (FR) and self-polishing (SP) paints under this kind of attack. The matrix was featured by different pH and free chlorine (free-Cl) values derived by a galvanostatic test performed at an anodic current density required for the protection of paints roughly at their mid age. Chemical/physical characterization was performed through visual analysis, thickness measurements, profilometry, contact angle measurements, and FTIR-ATR analysis. Both FR and SP paints underwent adhesive failure only in the harshest conditions, pH = 3/free-Cl 3–6 ppm, with unmodified chemistry of the polymers. Both paints exhibited no detachment in milder pH/free-Cl conditions, but thickness and contact angle reduction were observed. Finally, results were discussed inferring possible behaviors of the tested paints in real applications. [ABSTRACT FROM AUTHOR]

Concerns about climate change, urban air pollution and dependence on unstable and expensive supplies of foreign oil have led policy-makers and researchers to investigate alternatives to conventional petroleum-fuelled internal-combustion-engine vehicles in transportation. Because vehicles that get some or all of their power from an electric drivetrain can have low or even zero emissions of greenhouse gases (GHGs) and urban air pollutants, and can consume little or no petroleum, there is considerable interest in developing and evaluating advanced electric vehicles (EVs), including pure battery-electric vehicles, plug-in hybrid electric vehicles and hydrogen fuel-cell electric vehicles. To help researchers and policy-makers assess the potential of EVs to mitigate climate change and reduce petroleum use, this paper discusses the technology of EVs, the infrastructure needed for their development, impacts on emissions of GHGs, petroleum use, materials use, lifetime costs, consumer acceptance and policy considerations. [ABSTRACT FROM AUTHOR]

Cold rolled SS is suitable for deep drawing operations, however the presence of resilient scales or oxides on the surface can damage the deep drawing punch/die sets and emphasise creep phenomena of the material. These oxides can be formed during the hot rolling process preceding the cold one, or during the bright annealing performed between the steps of thickness reduction of the coil. Then a cleaning of the SS surface before drawing is necessary to have a longer life of the tools. The removal of the surface oxide scale can be performed with electrolytic pickling using neutral electrolytes, but the process parameters can be varied depending on the amount of oxides present on the surface of the starting material. To optimise the process efficiency, then, an univocal scale of the degree of oxidation of the bright annealed SS was determined through microscopical analysis and potentiodynamic tests. [ABSTRACT FROM AUTHOR]

A series of waterborne coatings obtained from aqueous dispersions of fluorinated polyurethane ionomers were characterized by Differential Scanning Calorimetry (DSC), Contact Angle measurements (CA), and Electrochemical Impedance Spectroscopy (EIS) with evaluation of water uptake and barrier properties at prolonged exposure. All the considered materials showed two glass transition temperatures and the formation of highly hydrophobic surfaces with CA values against water well above 100°. On the other hand the compositive parameters of the polymers—presence and concentration of cationic as well as anionic groups, linear or crosslinked molecular structure—showed a significant effect on the electrochemical behaviour. In particular it resulted that less water absorption is shown by coatings with lower ionic character, while crosslinked anionomer structures show excellent long-term barrier properties. The research offers useful indication towards the design of a new class of hydrophobic barrier coatings from aqueous dispersions. [ABSTRACT FROM AUTHOR]

This study was performed to investigate the electrochemical oxidation of anionic surfactants. In particular, a synthetic solution of sodium dodecyl benzene sulfonate and a real car wash wastewater were treated by galvanostatic electrolysis using a Ti-Ru-Sn ternary oxide and a boron-doped diamond (BDD) anode. Measurements of the Chemical Oxygen Demand (COD) and the concentration of the anionic surfactants were used to follow the oxidation. Using the Ti-Ru-Sn ternary oxide anode, the complete removal of COD and sodium dodecyl benzene sulfonate was obtained only in the presence of chloride ions that act as inorganic mediators. The oxidation rate was almost independent of current density and electrolyte flow rate. In the case of BDD the mineralisation of the sodium dodecyl benzene sulfonate was achieved in all experimental conditions due to reaction with hydroxyl radicals electrogenerated on the diamond surface during electrolysis. The COD removal rate increased with increase in electrolyte flow rate, indicating that the oxidation was mass-transfer controlled. Comparison of the results of the two electrodes showed that chlorine mediated oxidation at the Ti-Ru-Sn ternary oxide anode allowed a faster COD removal of both the synthetic solution and real car wash wastewater. [ABSTRACT FROM AUTHOR]

The electrochemical characteristics of composite cathodes consisting of Lanthanum Strontium Manganite (LSM) and Yttria Stabilised Zirconia (YSZ) have been analysed in order to emphasise the opportunity offered by these electrodes in the attempt to reduce the temperature of solid oxide fuel cells. Impedance analysis and potentiodynamic polarisation have been used as tools to evaluate the main electrochemical parameters and the results show that a volume ratio between LSM and YSZ close to 1 gives the best electrochemical activity because of the extension of the three phase boundary (TPB) in the electrode. Electrodes of this composition were subjected to high current load to verify the stability of the electrochemical performance and the results confirmed good cathode reliability. [ABSTRACT FROM AUTHOR]