Search results for "Graphene oxide"

Functionalization of Graphene with Molecules and/or Nanoparticles for Advanced Applications

2019

Graphene is considered the material of the third millennium, due to its extraordinary electronic and mechanical properties, and due to the possibility to modulate its conductivity, flexibility, elasticity, transparency, and biocompatibility by bottom-up approach. The possibility to gather the proper- ties of graphene and graphene oxide with those of functional moieties or nanoparticles is herein reviewed. The synthetic approaches proposed, either covalent or noncovalent, are aimed to tune appropriately graphene’s properties for the realization of materials for advanced uses, such as bio- medical applications, sensors, catalysis, and energy devices. In particular, methods based on covalent l…

Temperature influence on the synthesis of pristine graphene oxide and graphite oxide

2015

Abstract Derivative oxide carbon materials, such as graphene or graphite oxides, have been recently considered to be a promising material in a wide scenarios of emerging technologies due to their physical and chemical properties, as well as, for their low production costs. Even if apparently similar, these materials exhibit different physical and chemical properties. One of the critical issue is associated with the exfoliation process and contributes to the formation of graphene oxide and graphite oxide material. Here, we show a single synthetic wet method to produce graphene or graphite oxide by applying a control of the operational temperature during the reaction. The process was optimise…

Investigation of Acetone Vapour Sensing Properties of a Ternary Composite of Doped Polyaniline, Reduced Graphene Oxide and Chitosan Using Surface Pla…

2020

This work reports the use of a ternary composite that integrates p-Toluene sulfonic acid doped polyaniline (PANI), chitosan, and reduced graphene oxide (RGO) as the active sensing layer of a surface plasmon resonance (SPR) sensor. The SPR sensor is intended for application in the non-invasive monitoring and screening of diabetes through the detection of low concentrations of acetone vapour of less than or equal to 5 ppm, which falls within the range of breath acetone concentration in diabetic patients. The ternary composite film was spin-coated on a 50-nm-thick gold layer at 6000 rpm for 30 s. The structure, morphology and chemical composition of the ternary composite samples were character…

Facile and novel synthesis of Graphene oxide/Silica nanohybrids with tunable properties

2013

Sensors for the monitoring of analytes in the sweat

In the last decade, can be found an exceptional growth in research activity relating to the development of wearable devices, capable of continuously monitoring the health conditions of the wearer by analyzing body fluids such as blood, urine, saliva, tears and sweat. Among the body fluids available, sweat is a biofluid of particular interest, as it allows a non-invasive, continuous and comfortable collection. Human sweat contains useful information on the health of an individual and therefore is an excellent biofluid for the detection of specific analytes. The most abundant ions in the sweat are Na+ and Cl- (10 - 100 mM), and their monitoring is useful in patients with cystic fibrosis. Othe…

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…

A Novel Graphene Oxide-Silica Nanohybrid, Highly Functionalized by Organic Fluorotails

2015

GO-based composites have attracted increasing attention due to their improved properties: in this context Silica-GO nanohybrids are currently used in many fields, ranging from biomedicine to optoelectronics. In recent years growing interest of the materials community has been posed on the functionalization of graphene materials with fluorine: Fluorinated graphene oxide has been proven to be the first carbon material for Magnetic Resonance Imaging without the addition of magnetic nanoparticles,1 moreover, has proven to absorb NIR-laser energy and efficiently transform it into heat, so that fluorinated graphene oxide has been suggested as a contrast agent for MRI, ultrasound and photoacoustic…

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…

Carbon based nanomaterials for tissue engineering of bone: Building new bone on small black scaffolds: A review.

2019

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Graphene oxide-silica nanohybrids as fillers for PA6 based nanocomposites

2014

Graphene oxide (GO) was prepared by oxidation of graphite flakes by a mixture of H2SO4/H3PO4 and KMnO4 based on Marcano's method. Two different masterbatches containing GO (33.3%) and polyamide-6 (PA6) (66.7%) were prepared both via solvent casting in formic acid and by melt mixing in a mini-extruder (Haake). The two masterbatches were then used to prepare PA6-based nanocomposites with a content of 2% in GO. For comparison, a nanocomposite by direct mixing of PA6 and GO (2%) and PA6/graphite nanocomposites were prepared, too. The oxidation of graphite into GO was assessed by X-ray diffraction (XRD), Micro-Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectrosco…