0000000000161788

AUTHOR

Eliana Quartarone

showing 4 related works from this author

Optical properties of Ge-oxygen defect center embedded in silica films

2007

The photo-luminescence features of Ge-oxygen defect centers in a 100nm thick Ge-doped silica film on a pure silica substrate were investigated by looking at the emission spectra and time decay detected under synchrotron radiation excitation in the 10-300 K temperature range. This center exhibits two luminescence bands centered at 4.3eV and 3.2eV associated with its de-excitation from singlet (S1) and triplet (T1) states, respectively, that are linked by an intersystem crossing process. The comparison with results obtained from a bulk Ge-doped silica sample evidences that the efficiency of the intersystem crossing rate depends on the properties of the matrix embedding the Ge-oxygen defect ce…

Condensed Matter - Materials SciencePhotoluminescenceGermaniumSputteringOptical spectroscopyDefectsAbsorptionLuminescenceGermaniaSilicaDopingMaterials Science (cond-mat.mtrl-sci)FOS: Physical scienceschemistry.chemical_elementGermaniumDisordered Systems and Neural Networks (cond-mat.dis-nn)Atmospheric temperature rangeCondensed Matter - Disordered Systems and Neural NetworksCondensed Matter PhysicsPhotochemistryMolecular physicsElectronic Optical and Magnetic MaterialsCondensed Matter::Materials ScienceIntersystem crossingchemistryMaterials ChemistryCeramics and CompositesSinglet stateTriplet stateLuminescence
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PBI-based composite membranes for polymer fuel cells

2010

Abstract In the present study poly(2,2-(2,6-pyridin)-5,5-bibenzimidazole) was used for the preparation of novel MEAs for high-temperature polymer fuel cells (HT-PEMFCs). We prepared hybrid materials with two types of silica fillers in order to increase the MEA performances using this polymer. The membranes were characterized in terms of their microstructure and thermal stability. Cell operation tests and Electrochemical Impedance Spectroscopy were used for the characterization of the MEAs. A maximum power density of about 80 mW cm−2 was obtained at 300 mA cm−2 by using an imidazole-modified silica filler. The EIS technique showed that the fillers chiefly help to reduce the charge transfer r…

chemistry.chemical_classificationProton exchange membrane PBI Electrochemical Impedance SpectroscopyFiller (packaging)Materials scienceRenewable Energy Sustainability and the EnvironmentAnalytical chemistryEnergy Engineering and Power TechnologyProton exchange membrane fuel cellPolymerMicrostructureDielectric spectroscopyMembranechemistryChemical engineeringProton exchange membrane PBI Electrochemical Impedance SpectroscopyThermal stabilityElectrical and Electronic EngineeringPhysical and Theoretical ChemistryHybrid material
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Lithium ion conducting PVdF-HFP composite gel electrolytes based on N-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)-imide ionic li…

2010

Blends of PVDF-HFP and ionic liquids (ILs) are interesting for application as electrolytes in plastic Li batteries. They combine the advantages of the gel polymer electrolytes (GPEs) swollen by conventional organic liquid electrolytes with the nonflammability, and high thermal and electrochemical stability of ILs. In this work we prepare and characterize PVDF-HFP composite membranes swollen with a solution of LiTFSI in ether-functionalized pyrrolidinium-imide (PYRA12O1). The membranes are filled in with two different types of silica: i) mesoporous SiO2 (SBA-15) and a commercial nano-size one (HiSilTM T700). The ionic conductivity and the electrochemical properties of the gel electrolytes ar…

Materials sciencePVdFEnergy Engineering and Power TechnologyIonic bondingchemistry.chemical_elementElectrolyteIonic liquidchemistry.chemical_compoundIonic conductivityThermal stabilityElectrical and Electronic EngineeringPhysical and Theoretical ChemistryGel polymer electrolyteSettore CHIM/02 - Chimica FisicaChromatographyRenewable Energy Sustainability and the EnvironmentPVdF; Ionic liquids; Pyrrolidinium; Gel polymer electrolytes; Lithium battery; Nanoscale fillersLithium batteryLithium batteryMembraneSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialiChemical engineeringchemistryIonic liquidLithiumNanoscale fillerNanoscale fillersPyrrolidinium
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MCM-41 silica effect on gel polymer electrolytes based on thermoplastic polyurethane

2012

Abstract Polymer electrolytes were prepared from thermoplastic polyurethane with addition of mixture of N-ethyl(methylether)-N-methylpyrrolidinium trifluoromethanesulfonimide (PYRA12O1TFSI) ionic liquid, lithium bis(trifluoromethanesulfoneimide) salt and propylene carbonate. MCM-41 mesoporous silica was added in proportions ranging from 5 to 20 wt.% with respect to TPU. The electrolytes were characterized by thermogravimetric analysis, differential scanning calorimetry, linear voltammetry and impedance spectroscopy. The MCM-41 addition to the system was found to improve the electrochemical stability of the membranes and to reduce the gel electrolyte/metallic Li interfacial resistance. The f…

Thermogravimetric analysisMCM-41 mesoporous silicaMaterials scienceGeneral Chemical EngineeringLithium batterieThermoplastic polyurethaneImpedance spectroscopyElectrolyteLithium batteries Thermoplastic polyurethane Ionic liquid MCM-41 mesoporous silica Impedance spectroscopyIonic liquidMesoporous silicaDielectric spectroscopyThermoplastic polyurethanechemistry.chemical_compoundDifferential scanning calorimetryLithium batterieschemistryChemical engineeringIonic liquidPropylene carbonatePolymer chemistryElectrochemistrySettore CHIM/02 - Chimica FisicaElectrochimica Acta
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