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Saint-Martin-Vésubie, France

Laidani Y.,University of Hassiba Ben Bouali Chlef | Hanini S.,Dr. Yahia Fares University Center of Medea | Mortha G.,LGP2 | Heninia G.,University of Hassiba Ben Bouali Chlef
Iranian Journal of Chemistry and Chemical Engineering | Year: 2012

This study is devoted to the morphological, chemical and physical characterization of raw material of the fruit of Luffa Cylindrica. By microscopic analysis, it can be observed that the fruit is composed of an assembly of dependent cords, where four parts are differentiated: external, internal wall, core and bond. Each cord consists of hollow and flexible cylindrical fibers. The external part is richest in cellulose (80%). The mean contents cellulose of the various parts appears higher than those of wood fibers, and the lower percentages lignin (10%). The crystallinity index of cords cellulose was characterized by x-rays diffractometry; the measured value (69%). The thermophysical analysis showes that various kinetic phases of the adsorbed water drainage process and heat capacities measured being close to those of wood celluloses. Source

Gros F.,National Graduate School of Chemistry of Clermont Ferrand | Baup S.,Joseph Fourier University | Aurousseau M.,LGP2
Hydrometallurgy | Year: 2011

Cementation of copper ions onto a rotating disc electrode (RDE) of zinc and iron, either alone or associated as sacrificial metals is studied. The influence of operating temperature (10-50 °C range) confirms copper cementation limitation by mass transfer on iron and zinc, with the systems presenting mass transfer coefficients in the range 8-50 • 10- 5 m s- 1. Electrode potential changes indicate that the cathodic surface increases as cementation proceeds, where copper cement presents nearly 10 m2 g- 1 of specific surface. This results in a kinetic acceleration, underlined by the copper/iron system. These results also highlight that zinc metal is the main site of hydrogen evolution and thus lessens iron corrosion during hydronium ion reduction. Tests of iron protection by zinc via galvanic coupling did not fully succeed as iron is still released in the solution. © 2010 Elsevier B.V. Source

Gros F.,National Graduate School of Chemistry of Clermont Ferrand | Baup S.,Joseph Fourier University | Aurousseau M.,LGP2
Hydrometallurgy | Year: 2011

In this study, the cementation of copper ions on iron and zinc as sacrificial metals in a fluidized bed configuration was carried out. A preliminary hydrodynamic study checked the non-segregating behaviour of iron/zinc mixtures during fluidization experiments. The efficiency of the mixtures in copper recovery has been estimated in terms of kinetic and apparent mass transfer coefficients according to operating parameter modifications. The influence of temperature on the kinetics revealed a mass transfer limitation of the reaction, with an activation energy of 19.6 kJ mol-1. Maximum apparent mass transfer (13.6 • 10-5 m s-1) was obtained for a 1.5 pH solution due to the presence of hydrogen bubbles that increase local mass transfer. Acid and sacrificial metal consumptions revealed an over-consumption of zinc compared to iron due to copper catalysed hydrogen evolution. The influence of initial copper concentration in the 50-1000 ppm range shows that kinetic and mass transfer dependence is due to modifications of the copper deposit morphology. © 2010 Elsevier B.V. Source

Gopalakrishnan P.,LGP2 | Narayan-Sarathy S.,PepsiCo | Ghosh T.,PepsiCo | Mahajan K.,PepsiCo | Belgacem M.N.,LGP2
Journal of Polymer Research | Year: 2014

Recent work in biomass-based furanic polyesters has shown that they deliver a good balance of sustainability advantage with improved performance and economics. In light of that research, completely renewable furanic polyesters with novel compositions and enhanced performance were synthesized using two different polymerization methods and characterized. These materials, based on ethylene glycol (PEF) and 1,4-Butanediol (PBF), exhibit thermal and structural properties similar to fossil-based poly (ethylene terephthalate) (PET), which is widely used in beverage packaging. Direct polycondensation method resulted in doubling the yield of polymer with properties identical to those of material synthesized using trans-esterification. PBF synthesized using our process has unique thermal properties (higher glass transition and lower melting temperature) that could result in lower costs and environmental impacts associated with the processing step. The other new polymer compositions were also well characterized for potential high-temperature applications. The biomass-based furanic polyesters are a potential sustainable alternative for petroleum-based PET in packaging applications. © 2013 Springer Science+Business Media Dordrecht. Source

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