Search results for " 25"

showing 10 items of 220 documents

High-performance thermoplastic elastomers/carbon nanotubes nanocomposites: Mechanical behavior, rheology, and durability

2015

Advanced polystyrene-b-polybutadiene-b-polystyrene (SBS) based nanocomposites containing bare carbon nanotubes (CNTs) and CNTs bearing hydroxyl functional groups (CNTs-OH) have been formulated and fully characterized. In particular, the reinforcement effect of CNTs and CNTs-OH on SBS was deeply investigated through mechanical and dynamical thermo-mechanical analysis and the rheological response of SBS-based nanocomposites was investigated and discussed. The mechanical properties of SBS/CNTs and even more of SBS/CNTs-OH nanocomposites are substantially superior to those of neat SBS, due to the uniformly dispersed nanofillers throughout the polymeric matrix. The presence of -OH groups onto CN…

Materials Chemistry2506 Metals and AlloysMaterials sciencePolymers and PlasticsCeramics and CompositeElectron donor02 engineering and technologyCarbon nanotube010402 general chemistry01 natural scienceslaw.inventionchemistry.chemical_compoundRheologylawCeramics and Composites; Chemistry (all); Polymers and Plastics; Materials Chemistry; 2506; Metals and AlloysMaterials ChemistryThermoplastic elastomerComposite materialchemistry.chemical_classificationPolymers and PlasticNanocompositeChemistry (all)Metals and AlloysGeneral ChemistryPolymer021001 nanoscience & nanotechnologyDurability0104 chemical scienceschemistryCeramics and CompositesDegradation (geology)25060210 nano-technologyPolymer Composites
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Concentration-dependent anti-/pro-oxidant activity of natural phenolic compounds in bio-polyesters

2017

Abstract In this work, the potential of several naturally occurring phenolic compounds, such as Ferulic Acid (FA), Vanillic Acid (VA), Vitamin E (VE) and Quercetin (Q), as stabilizers against the photo-oxidative degradation of Polylactic acid (PLA) has been assessed. Specifically, PLA-based films containing different amounts of considered stabilizers have been formulated and their photo-stability under UVB exposure has been evaluated. The preliminary characterization of the formulated films shows that all used stabilizers exert plasticizing action, as probed by rheological analysis, due to their low molecular weight. Moreover, no significant modification of the PLA crystallinity has been no…

Materials Chemistry2506 Metals and AlloysMaterials sciencePolymers and Plasticsmedicine.medical_treatmentCondensed Matter Physic02 engineering and technology010402 general chemistry01 natural sciencesAnti-/pro-oxidant activity; Natural stabilizers; Photo-oxidation; Polylactic acid; Condensed Matter Physics; Mechanics of Materials; Polymers and Plastics; Materials Chemistry; 2506; Metals and AlloysPolylactic acidFerulic acidCrystallinitychemistry.chemical_compoundPolylactic acidMaterials ChemistrymedicineVanillic acidOrganic chemistryPhoto-oxidationMechanics of MaterialNatural stabilizersNatural stabilizerPolymers and PlasticVitamin EMetals and Alloys021001 nanoscience & nanotechnologyCondensed Matter PhysicsPro-oxidantAnti-/pro-oxidant activity0104 chemical sciencesPolyesterchemistryMechanics of Materials25060210 nano-technologyQuercetin
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Thiophene pyrenyl derivatives for the supramolecular processability of single-walled carbon nanotubes in thin film heterojunction

2017

Abstract A major problem for the use of single-wall carbon nanotubes (SWCNTs) in electronic devices relates to their poor processability. Chemical modification inevitably introduces defects in the nanotube lattice, resulting in a loss of electronic properties. In this contest, we report on a supramolecular approach with the aim of increasing the dispersion of SWCNTs in solution and in organic semiconductor matrices by ensuring the optoelectronic properties. In particular, new pyrenyl derivatives of thiophene have been synthesized and used to improve the solubility of SWCNTs for electron transfer in thin film heterojunction with poly(3-hexylthiophene) (P3HT) as donor system. Photoinduced ele…

Materials Chemistry2506 Metals and AlloysNanotubeMaterials scienceCarbon nanotubes02 engineering and technologyCarbon nanotube010402 general chemistryPhotochemistry01 natural sciencesCarbon nanotubePhotoinduced electron transferlaw.inventionchemistry.chemical_compoundElectron transferCarbon nanotubes; Fluorescence quenching; Heterojunctions; Organic photovoltaics; Pyrene; Electronic Optical and Magnetic Materials; Condensed Matter Physics; Mechanics of Materials; Mechanical Engineering; 2506; Materials Chemistry2506 Metals and AlloyslawElectronicMaterials ChemistryThiopheneMoietyOptical and Magnetic MaterialsAlkylSettore CHIM/02 - Chimica Fisicachemistry.chemical_classificationPyreneMechanical EngineeringMetals and AlloysSettore CHIM/05 - Scienza E Tecnologia Dei Materiali PolimericiSettore CHIM/06 - Chimica Organica021001 nanoscience & nanotechnologyCondensed Matter Physics0104 chemical sciencesElectronic Optical and Magnetic MaterialsFluorescence quenchingOrganic semiconductorchemistrySettore CHIM/03 - Chimica Generale E InorganicaMechanics of MaterialsOrganic photovoltaicsHeterojunctionsHeterojunctionOrganic photovoltaic25060210 nano-technologySynthetic Metals
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Organic-inorganic nanocomposites prepared by reactive suspension method: investigation on filler/matrix interactions and their effect on the nanopart…

2017

Epoxy resin/TiO2 nanocomposites prepared by both reactive suspension method, based on in situ synthesis, and conventional mechanical mixing are analysed by solid-state nuclear magnetic resonance and transmission electron microscopy in order to have a deeper insight into the nature of interactions at the polymer/particle interface and their effect on the nanoparticles dispersion. Specifically, solid-state nuclear magnetic resonance experiments showed that the nanoparticles, synthesized by reactive suspension method, can efficiently link the matrix by hydrogen bonds forming a hybrid organic-inorganic 3D network. Such evidences strongly supports our previously reported theory, in which the nan…

Materials Chemistry2506 Metals and AlloysPolymers and PlasticsReactive suspension methodNanoparticle02 engineering and technology010402 general chemistry01 natural sciencesColloid and Surface ChemistryNanoparticles/polymer interfaceH-bondsMaterials ChemistryComposite materialPhysical and Theoretical ChemistrySuspension (vehicle)chemistry.chemical_classificationNanocompositeDispersion; H-bonds; Hybrid nanocomposite; Nanoparticles/polymer interface; Reactive suspension method; Physical and Theoretical Chemistry; Polymers and Plastics; Colloid and Surface Chemistry; Materials Chemistry2506 Metals and AlloysPolymers and PlasticMetals and AlloysPolymerEpoxyDispersionHybrid nanocomposite021001 nanoscience & nanotechnologyH-bondDispersion; H-bonds; Hybrid nanocomposite; Nanoparticles/polymer interface; Reactive suspension method; Physical and Theoretical Chemistry; Polymers and Plastics; Colloid and Surface Chemistry; Materials Chemistry; 2506; Metals and Alloys0104 chemical scienceschemistryTransmission electron microscopyvisual_artvisual_art.visual_art_mediumParticle25060210 nano-technologyDispersion (chemistry)
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Supramolecular Design of Low-dimensional Carbon Nano-hybrids encoding a Polyoxometalate-bis-Pyrene Tweezer

2014

A novel bis-pyrene tweezer anchored on a rigid polyoxometalate scaffold fosters a unique interplay of hydrophobic and electrostatic supramolecular interactions, to shape carbon nanostructures (CNSs)-based extended architectures.

Materials Chemistry2506 Metals and AlloysSurfaces Coatings and FilmCarbon nanotubelaw.inventionCatalysiCoatings and Filmschemistry.chemical_compoundlawhybrid materialsMaterials ChemistryCarbon nanostructures; recognition; hybrid materials; polyoxometalatesMaterials Chemistry2506 Metals and AlloyPyrenesPyreneElectronic Optical and Magnetic MaterialChemistry (all)Metals and AlloysTungsten CompoundsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsSurfacesSpectrophotometryPolyoxometalatePyrenerecognitionLangmuir-Schaefer filmsHybrid materialHydrophobic and Hydrophilic InteractionsCarbon nanostructuresMaterials scienceStatic ElectricitySupramolecular chemistrychemistry.chemical_elementNanotechnologyCeramics and CompositeCarbon nanotubeCatalysisNano-ElectronicpolyoxometalatesChemistry (all); Catalysis; Ceramics and Composites; Electronic Optical and Magnetic Materials; Surfaces Coatings and Films; Materials Chemistry2506 Metals and Alloys; 2506Optical and Magnetic Materialscarbon nanotubeHybrid materialPolyoxometalateGeneral ChemistryCarbon nanostructuresCarbonNanostructureschemistryCeramics and Composites2506Supramolecular chemistryCarbon
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Enhancement of photoconversion efficiency in dye-sensitized solar cells exploiting pulsed laser deposited niobium pentoxide blocking layers

2015

Abstract Among all the photovoltaic technologies developed so far, dye-sensitized solar cells are considered as a promising alternative to the expensive and environmentally unfriendly crystalline silicon-based solar cells. One of the possible strategies employed to increase their photovoltaic efficiency is to reduce the charge recombination at the cell conductive substrate through the use of a compact blocking layer. In this paper, we report on the fabrication and characterization of dye-sensitized solar cells employing niobium pentoxide (Nb 2 O 5 ) thin film blocking layer deposited through the pulsed laser deposition technique on conductive substrates. The careful selection of the optimal…

Materials scienceOpen circuit voltage decaySubstrate (electronics)Dye-sensitized solar cellsSettore ING-INF/01 - ElettronicaPulsed laser depositionBlocking layer; Dye-sensitized solar cells; Electrochemical impedance spectroscopy; Niobium pentoxide; Open circuit voltage decay; Pulsed laser deposition; Electronic Optical and Magnetic Materials; Materials Chemistry; 2506; Metals and Alloys; 2506; Surfaces Coatings and Films; Surfaces and InterfacesCoatings and Filmschemistry.chemical_compoundElectronicMaterials ChemistryOptical and Magnetic MaterialsCrystalline siliconThin filmNiobium pentoxidepulsed laser depositionbusiness.industryOpen-circuit voltagePhotovoltaic systemMetals and AlloysSurfaces and InterfacesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsSurfacesDye-sensitized Solar CellDye-sensitized solar cellniobium pentoxidechemistryblocking layerOptoelectronics2506businessElectrochemical impedance spectroscopyThin Solid Films
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Advanced ultra-high molecular weight polyethylene/antioxidant-functionalized carbon nanotubes nanocomposites with improved thermo-oxidative resistance

2015

Multiwalled carbon nanotubes (CNTs) functionalized with hindered phenol moieties are dispersed in ultra-high molecular weight polyethylene (UHMWPE), and the stabilizing action of the antioxidant (AO) functionalized CNTs (AO-f-CNTs) is studied through a combination of rheological and spectroscopic (FT-IR) analyses. The effectiveness of two alternative compounding methods, namely hot compaction (HC) and melt mixing (MM), is compared. The combination of high temperature and mechanical stress experienced during MM brings about noticeable degradation phenomena of the matrix already in the course of the compounding step. Differently, the milder conditions of the HC process preserve the stability …

Materials sciencePolymers and PlasticsCarbon nanotubelaw.inventionnanotubesCoatings and Filmschemistry.chemical_compoundlawgraphene and fullerenesMaterials Chemistrydegradation graphene and fullerenes nanotubes polyolefinsComposite materialpolyolefindegradationchemistry.chemical_classificationUltra-high-molecular-weight polyethyleneNanocompositeChemistry (all)Metals and AlloysGeneral ChemistryPolymerPolyethyleneGraftingdegradation; graphene and fullerenes; nanotubes; polyolefins; Chemistry (all); Surfaces Coatings and Films; Polymers and Plastics; Materials Chemistry; 2506; Metals and AlloysSurfaces Coatings and FilmsSurfaceschemistryCompoundinggraphene and fullerenenanotube2506Dispersion (chemistry)polyolefins
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Double bond-functionalized POSS: dispersion and crosslinking in polyethylene-based hybrid obtained by reactive processing

2016

Polyethylene-based organic inorganic hybrids were prepared by one-step reactive melt mixing using a mono-functionalized nanofiller, i.e., allyl-heptaisobutyl-substituted polyhedral oligomeric silsesquioxane (1POSS) and a multi-functionalized octavinyl polyhedral oligomeric silsesquioxane (8POSS). The hybrids were also prepared in dicumyl peroxide (DCP) presence and morphological, spectroscopical and calorimetric analysis were carried out. Moreover, rheological measurement and Sohxlet extraction were performed on investigated samples. It was inferred that double bonds of POSS functional groups were triggered by radicals coming from the peroxide decomposition or from the degradation reactions…

Materials sciencePolymers and PlasticsDouble bond02 engineering and technology010402 general chemistry01 natural sciencesPeroxidechemistry.chemical_compoundPolymer chemistryMaterials ChemistryMoleculeChemistry (all); Condensed Matter Physics; Polymers and Plastics; Materials Chemistry; 2506; Metals and AlloysMaterials Chemistry2506 Metals and Alloychemistry.chemical_classificationPolymers and PlasticChemistry (all)Metals and AlloysGeneral ChemistryPolyethylene021001 nanoscience & nanotechnologyCondensed Matter PhysicsSilsesquioxane0104 chemical sciencesPolyolefinchemistryCovalent bond25060210 nano-technologyDispersion (chemistry)Polymer Bulletin
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Mechanical and rheological properties of polystyrene-block-polybutadiene-block-polystyrene copolymer reinforced with carbon nanotubes: effect of proc…

2017

Abstract Styrene-b-butadiene-b-styrene (SBS)-based nanocomposites filled with unmodified and –COOH functionalized carbon nanotubes (CNTs) have been formulated at different processing conditions in order to provide an understanding of the influence of the processing temperature and mixing speed on the nanofillers dispersion and on the overall properties of the nanocomposites. The evaluation of the nanocomposites’ mechanical and rheological behavior reveals that the effect of the processing speed on the final properties is almost negligible. Differently, the processing temperature influences strongly the mechanical and rheological properties of SBS-based nanocomposites. Indeed, for the nanoco…

Materials sciencePolymers and PlasticsGeneral Chemical EngineeringCarbon nanotubes (CNTs); Mechanical properties; Polystyrene-block-polybutadiene-block-polystyrene; Processing conditions; Rheological behavior; Chemical Engineering (all); Polymers and Plastics; Materials Chemistry; 2506; Metals and AlloysMechanical properties02 engineering and technologyCarbon nanotube010402 general chemistryPolystyrene-block-polybutadiene-block-polystyrene01 natural scienceslaw.inventionchemistry.chemical_compoundPolybutadieneRheologylawBlock (telecommunications)Materials ChemistryCopolymerChemical Engineering (all)Processing conditionComposite materialProcessing conditionsMetals and AlloysRheological behavior021001 nanoscience & nanotechnology0104 chemical scienceschemistryCarbon nanotubes (CNTs)Polystyrene25060210 nano-technologyMechanical propertieJournal of Polymer Engineering
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Thermo-oxidative resistant nanocomposites containing novel hybrid-nanoparticles based on natural polyphenol and carbon nanotubes

2015

Abstract Quercetin (Q), a natural antioxidant molecule, is physically immobilized onto multi-walled carbon nanotubes (CNTs) bearing covalently-linked long-chain alkyl functional groups, and the so obtained hybrid-nanoparticles are used to prepare Ultra High Molecular Weight PolyEthylene-based nanocomposite films with enhanced thermo-oxidation resistance. The effective immobilization of the Q molecules is confirmed by spectroscopic (micro-Raman, ATR-FTIR, and FTIR) and thermo-gravimetric analyses, and the influence of the nanoparticles on the rheological behaviour and thermo-oxidative stability of the nanocomposites are investigated. Rheological analyses (linear viscoelasticity and stress re…

Materials sciencePolymers and PlasticsNanoparticleMulti-walled carbon nanotubesCarbon nanotubeNanocompositeslaw.inventionchemistry.chemical_compoundUltra-high molecular weight polyethylene (UHMWPE)lawMaterials ChemistryMoleculeMechanics of MaterialSolubilityComposite materialAlkylMaterials Chemistry2506 Metals and AlloyUltra-high-molecular-weight polyethylenechemistry.chemical_classificationPolymers and PlasticNanocompositeNanocompositeMetals and AlloysMulti-walled carbon nanotubes; Nanocomposites; Quercetin; Thermo-oxidation resistance; Ultra-high molecular weight polyethylene (UHMWPE); Condensed Matter Physics; Mechanics of Materials; Polymers and Plastics; Materials Chemistry; 2506; Metals and AlloysPolyethyleneCondensed Matter PhysicsMulti-walled carbon nanotubeSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialiChemical engineeringchemistryMechanics of MaterialsQuercetin2506Thermo-oxidation resistancePolymer Degradation and Stability
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