Search results for "GRAPHENE OXIDE"

showing 10 items of 82 documents

Photothermal nanofibrillar membrane based on hyaluronic acid and graphene oxide to treat Staphylococcus aureus and Pseudomonas aeruginosa infected wo…

2022

Here we reported the fabrication of an electrospun membrane based on a hyaluronic acid derivative (HA-EDA) to be used as a bandage for the potential treatment of chronic wounds. The membrane, loaded with graphene oxide (GO) and ciprofloxacin, showed photothermal properties and light-triggered drug release when irradiated with a near-infrared (NIR) laser beam. Free amino groups of HA-EDA derivative allowed autocrosslinking of the elec- trospun membrane; thus, a substantial enhancement in the hydrolytic resistance of the patch was obtained. In vitro antibacterial activity studies performed on Staphylococcus aureus and Pseudomonas aeruginosa revealed that such electrospun membranes, due to the…

Staphylococcus aureusGeneral MedicineStaphylococcal InfectionsBiochemistryHyaluronan derivative Graphene oxide Nanofibers AntibiofilmAnti-Bacterial AgentsStructural BiologySettore CHIM/09 - Farmaceutico Tecnologico ApplicativoPseudomonas aeruginosaWound InfectionHumansGraphiteHyaluronic AcidMolecular BiologyInternational journal of biological macromolecules
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FLEXIBLE ELECTRODE BASED ON GOLD NANOPARTICLES AND REDUCED GRAPHENE OXIDE FOR URIC ACID DETECTION USING LINEAR SWEEP VOLTAMMETRY

2021

In this work, an electrochemical sensor for uric acid determination is shown with a preliminary study for its validation in real samples (milk and urine). Uric acid can be electrochemically oxidized in aqueous solutions and thus it is possible to obtain electrochemical sensors for this chemical by means of this electrooxidation reaction. Indium tin oxide coated on flexible polyethylene terephthalate substrate, modified with reduced graphene oxide and gold nanoparticles by co-electrodeposition, was used. Electrodeposition was performed at -0.8V vs SCE for 200 s. All samples were characterized by electron scan microscopy and electron diffraction spectroscopy. A careful investigation on the ef…

TK7885-7895Computer engineering. Computer hardwareMilkChemical engineeringSettore ING-IND/23 - Chimica Fisica ApplicataElectrochemical sensorTP155-156UrineUric acidUric acid Electrochemical sensors Reduced graphene oxide Gold nanoparticles Milk Urine
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Interfacial Self-Assembly to Spatially Organize Graphene Oxide Into Hierarchical and Bioactive Structures

2020

Multicomponent self-assembly holds great promise for the generation of complex and functional biomaterials with hierarchical microstructure. Here, we describe the use of supramolecular co-assembly between an elastin-like recombinamer (ELR5) and a peptide amphiphile (PA) to organize graphene oxide (GO) flakes into bioactive structures across multiple scales. The process takes advantage of a reaction—diffusion mechanism to enable the incorporation and spatial organization of GO within multiple ELR5/PA layers. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ImageJ software were used to demonstrate the hierarchical organization of GO flakes within the ELR5/PA lay…

TechnologyMaterials scienceBiocompatibilityScanning electron microscopeMaterials Science (miscellaneous)Materials Sciencecomposite materialsFABRICATIONMaterials Science Multidisciplinaryhierarchical biomaterialsNanotechnology02 engineering and technology010402 general chemistrylcsh:Technology01 natural scienceselastin-like recombinamerlaw.inventionDESIGNlawPeptide amphiphileBIOMATERIALS0912 Materials EngineeringCHITOSANScience & Technology1007 Nanotechnologylcsh:TGrapheneSCAFFOLD021001 nanoscience & nanotechnologyMicrostructurepeptide amphiphiles0104 chemical sciencesmulticomponent self-assemblyDIFFERENTIATIONMembraneTransmission electron microscopygraphene oxideSelf-assembly0210 nano-technologyFILMFrontiers in Materials
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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Synthesis, Characterization and Sorption Capacity Examination for a Novel Hydrogel Composite Based on Gellan Gum and Graphene Oxide (GG/GO)

2020

A novel hydrogel composite based on gellan gum and graphene oxide (GG/GO) was synthesized, characterized and tested for sorption capacity in this work. The microstructural, thermogravimetric and spectroscopic analysis confirmed the formation of the GG/GO composite. Comparative batch sorption experiments revealed a sorption capacity of the GG/GO composite for Zn (II) ions of approximately 2.3 higher than that of pure GG. The GG/GO composite exhibits a maximum sorption capacity of 272.57 mg/g at a pH of Zn (II) initial solution of 6. Generally, the sorption capacity of the sorbents is approximately 1.5 higher in slightly acidic conditions (pH 6) comparative with that for strong acidic conditi…

Thermogravimetric analysisPolymers and PlasticsIon exchangehydrogel compositeComposite numberOxidezinc sorptionSorptionGeneral ChemistryArticleGellan gumlcsh:QD241-441chemistry.chemical_compoundlcsh:Organic chemistrychemistryChemisorptionMonolayergraphene oxidegellan gumNuclear chemistryPolymers
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Functionalised poly (vinyl alcohol)/graphene oxide as polymer composite electrolyte membranes

2019

[EN] Crosslinked poly(vinyl alcohol) (PVA) based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells (DEFC). The membranes were functionalised by means of the addition of graphene oxide (GO) and sulfonated graphene oxide (SGO) and crosslinked with sulfosuccinic acid (SSA). The chemical structure was corroborated and suitable thermal properties were found. Although the addition of GO and SGO slightly decreased the proton conductivity of the membranes, a significant reduction of the ethanol solution swelling and crossover was encountered, more relevant for those functionalised with SGO. In general, the composite membranes were stable under …

Vinyl alcoholProton conductivityMaterials sciencePoly(vinyl alcohol)Materials Science (miscellaneous)Oxide02 engineering and technologyElectrolyteEnvironmental Science (miscellaneous)010402 general chemistry01 natural scienceslaw.inventionchemistry.chemical_compoundlawCIENCIA DE LOS MATERIALES E INGENIERIA METALURGICAmedia_common.cataloged_instanceEuropean unionmedia_commonGraphene oxideMaterials compostosGrapheneProton exchange membranesTermoplàsticsCiència dels materials021001 nanoscience & nanotechnologyDirect-ethanol fuel cell0104 chemical sciencesMembranechemistryChemical engineeringMAQUINAS Y MOTORES TERMICOSPolymer compositesDirect ethanol fuel cell0210 nano-technology
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Preparation and mechanical characterization of polycaprolactone/graphene oxide biocomposite nanofibers

2016

Biocomposite nanofiber scaffolds of polycaprolactone (PCL) filled with graphene oxide (GO) were prepared using electrospinning technology. Morphological and mechanical properties of the scaffolds were characterized in dry and wet environment. The results showed that the successful incorporation of GO nanosheets into PCL polymer nanofibers improved their mechanical properties. Furthermore it was demonstrated the higher performance achieved when GO is filled at low concentration in the nanofibers.

chemistry.chemical_classificationMaterials scienceElectrospinningGrapheneOxidePolymerElectrospinninglaw.inventionPolycaprolactoneTissue engineering.chemistry.chemical_compoundchemistryChemical engineeringTissue engineeringlawNanofiberPolycaprolactoneBiocompositeComposite materialGraphene oxideAIP Conference Proceedings
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Synthesis and self-assembly of a PEGylated-graphene aerogel

2016

Abstract In the frame of this work, we present, for the first time, the synthesis and self-assembly of an aerogel built by graphene oxide-polyethylene glycol. The synthetic route involves at first the coupling of GO with an amino-terminated polyethylene glycol sample by carbodiimide in aqueous environment, and the subsequent conversion of the hydrogel achieved into an aerogel via freeze-drying. The 3D PEGylated graphene-based aerogel, characterized by spectroscopic, morphological, structural and mechanical analyses, displays an ultralight and highly porous (99.7%) network and possesses high mechanical properties together with a good biocompatibility.

del-assemblyMaterials sciencesynthesisBiocompatibility02 engineering and technologyPolyethylene glycol010402 general chemistry01 natural scienceslaw.inventionchemistry.chemical_compoundEngineering (all)lawHighly porousB.Stress/strain curveD.Raman spectroscopycharacterizationComposite materialGraphene oxideCarbodiimidePEGylated-grapheneAqueous solutionGraphenetechnology industry and agricultureGeneral EngineeringAerogel021001 nanoscience & nanotechnologyB.Porosity/void0104 chemical scienceschemistryCeramics and CompositesSelf-assembly0210 nano-technologyA.Functional compositeComposites Science and Technology
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Electrical measurements of femtosecond laser treated graphene

2017

Tutkielman pääasiallinen tavoite oli valmistaa sähköisiin mittauksiin sopivia grafeenilaitteita ja tutkia femtosekuntilaserkäsittelyn vaikutusta grafeenin sähköisiin ominaisuuksiin. Tutkielmassa käsitellään grafeenin valmistamista kemiallisella kaasufaasipinnoituksella, laitegeometrian määrittelyä ja käsittelemättömän, sekä femtosekuntilaserilla käsitellyn grafeenin sähköisiä mittauksia. Grafeenin synteesin alustana käytettiin kupariohutkalvoja ja pääasiallisena lähtöaineena oli etanoli tai metaani. Metaanin käyttö grafeenin synteesissä johti paremmin toistettaviin tuloksiin. Lisäksi havaittiin, että synteesissä käytetyn uunin latausjärjestelmän teräksinen osa lisäsi kupariohutkalvon reikii…

femtosekuntilaserfemtosecond lasersähköiset ominaisuudetgrapheneelectrical propertiesgrafeenifunktionalisaatiographene oxidefunctionalizationgrafeenioksididopingdouppaus
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Synthesis of a biocompatible aerogel based on graphene oxide and a modified polyethylene glycol

2016

The synthesis and self-assembly of a 3D aerogel built by graphene oxide (GO) and a modified polyethylene glycol (PEG) was achieved by a multi-step synthetic procedure, involving the preparation of an amino-terminated PEG (PEG-NH2) and the subsequent coupling with GO by carbodiimide in water, exploiting the carboxyl and epoxy moieties of GO and –NH2 terminations of the biopolymer. The resulting nanohybrid hydrogel was successively converted into an aerogel via dialysis plus freeze-drying [1] and fully characterized. FTIR, Raman, XPS, XRD and BET measurements were performed to confirm the successful modification for each reaction step, while morphological, mechanical and hemolytic tests were …

graphene oxide PEG aerogel graphene
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