Search results for " multi-walled carbon nanotubes"

showing 3 items of 3 documents

Construction of green nanostructured heterogeneous catalysts via non-covalent surface decoration of multi-walled carbon nanotubes with Pd(II) complex…

2017

Abstract Green nanostructured heterogeneous catalysts were prepared via a bottom-up strategy. Designed ligands were synthesized joining covalently an electrondeficient pyrimidine residue and a scorpiand azamacrocycle. The desired molecular properties were easily transferred to nanostructured materials in two steps: first, exploiting their spontaneous chemisorption onto multi-walled carbon nanotubes (MWCNTs) via the pyrimidinic moiety in water at room temperature, then, taking advantage of the easy coordination of Pd(II) to the azamacrocycle in the same conditions. An evenly distribution of catalytic centres was obtained on the MWCNTs surface. Catalytic properties of these materials were ass…

ChemistryAzamacrocycles Hybrid materials Multi-walled carbon nanotubes Non-covalent functionalization Palladium(II) catalysis Sonogashira cross coupling CatalysisSonogashira coupling02 engineering and technologyCarbon nanotube010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesCatalysis0104 chemical scienceslaw.inventionCatalysisResidue (chemistry)Chemical engineeringlawCovalent bondChemisorptionMoietyOrganic chemistryPhysical and Theoretical Chemistry0210 nano-technologyHybrid material
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Rheological Percolation Threshold in High-Viscosity Polymer/CNTs Nanocomposites

2017

AbstractPolystyrene (PS)/multi-walled carbon nanotubes (CNT) nanocomposites have been prepared through melt mixing processing aiming at obtaining a uniform and homogeneous dispersion of the used nanoparticles within the polymeric matrix. Optical and scanning electron microscopy has been employed to determine the dispersion and distribution of CNTs at different length scales. Furthermore, the linear viscoelastic behavior of formulated nanocomposites has been deeply investigated. As a result of CNTs added, the nanocomposites experience a transition from liquid-like to solid-like rheological behavior, and a disappearance of relaxation processes at low frequency can be noticed. By plotting G’ v…

Materials scienceScanning electron microscopePolystyrene (PS) multi-walled carbon nanotubes Rheological percolation nanocompositesPhysics::Medical PhysicsPhysics::Optics02 engineering and technologyCarbon nanotube010402 general chemistry01 natural sciencesViscoelasticitylaw.inventionCondensed Matter::Materials ScienceRheologylawComposite materialchemistry.chemical_classificationNanocompositeMechanical EngineeringPercolation thresholdPolymer021001 nanoscience & nanotechnology0104 chemical sciencesCondensed Matter::Soft Condensed MatterchemistryMechanics of Materials0210 nano-technologyDispersion (chemistry)Mechanics of Materials; Mechanical Engineering
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Improvement of interaction in and properties of PMMA-MWNT nanocomposites through microwave assisted acid treatment of MWNT

2013

Soluble derivatives of multi-walled carbon nanotubes (MWNT) embedded in a poly(methylmethacrylate) (PMMA) matrix forming thick, homogeneous and transparent nanocomposites, were prepared and characterized. A new photo-assisted method using microwaves, to purify the MWNTs from amorphous carbon and synthesis catalyst clusters, was tested in a sulphonitric mix. This method shortened the processing time compared to other methods. Pristine and functionalized MWNTs were introduced into the MMA, then in situ photo-polymerized. Transmission electron microscopy (TEM) and X-ray diffractometry (XRD), as well as Fourier-transform infrared (FTIR), Raman and nuclear magnetic resonance (NMR) spectroscopy w…

Microwave-assisted purificationThermogravimetric analysisThermal propertiesMaterials sciencePolymers and PlasticsGeneral Physics and AstronomyCarbon nanotubePMMA; Multi-walled carbon nanotubes; Microwave-assisted purification; Nanocomposite structure; Thermal propertieslaw.inventionsymbols.namesakeDifferential scanning calorimetrylawMaterials ChemistryComposite materialFourier transform infrared spectroscopySettore CHIM/02 - Chimica Fisicachemistry.chemical_classificationNanocompositeOrganic Chemistrytechnology industry and agriculturePolymerPMMAMulti-walled carbon nanotubeAmorphous carbonChemical engineeringchemistrysymbolsRaman spectroscopyNanocomposite structureEuropean Polymer Journal
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