scholarly journals Electrophysical and Morphological Properties of a Hydrothermally Synthesized CuFe2O4 and CuFe2O4 / Reduced Graphene Oxide Composite

2021 ◽  
Vol 22 (2) ◽  
pp. 372-379
Author(s):  
V.O. Kotsyubynsky ◽  
V.M. Boychuk ◽  
R.I. Zapukhlyak ◽  
M.A. Hodlevskyi ◽  
I.M. Budzulyak ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Composite Material ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Morphological Properties ◽  
Copper Ferrite ◽  
Spectroscopy Data ◽  
Oxide Composite ◽  
Reduced Graphene ◽  
Transfer Mechanisms

The aim of this paper is to compare the structural, morphological and electrical properties of the CuFe2O4 and CuFe2O4 / reduced graphene oxide composite. XRD and Mossbauer studies have shown that joint hydrothermal synthesis of cubic copper ferrite and reduction of graphene oxide leads to a decrease in ferrite particles from 14 to 8 nm. Based on the impedance spectroscopy data, a model of the obtained composite material has been prepared as a system consisting of contacting spinel particles covered with rGO clusters and separated by porous rGO. For CuFe2O4 / rGO composite material, the predominance of hopping charge transfer mechanisms has been shown, and the activation energies of electrical conductivity of grains and grain boundaries have been calculated.

Cobalt-iron spinel/reduced graphene oxide composite material for supercapacitor applications

2021 ◽  
Vol 717 (1) ◽  
pp. 60-71
Author(s):  
M. A. Hodlevska ◽  
R. I. Zapukhlyak ◽  
V. M. Boychuk ◽  
V. O. Kotsyubynsky ◽  
A. I. Kachmar ◽  
...  
Keyword(s):  
Composite Material ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Oxide Composite ◽  
Reduced Graphene ◽  
Cobalt Iron ◽  
Oxide Composite Material ◽  
Supercapacitor Applications

Reduced graphene oxide–reinforced gellan gum thermoresponsive hydrogels as a myocardial tissue engineering scaffold

2019 ◽  
Vol 34 (4-5) ◽  
pp. 331-345 ◽  
Author(s):  
Seyed Mohammad Zargar ◽  
Mehdi Mehdikhani ◽  
Mohammad Rafienia
Keyword(s):  
Electrical Conductivity ◽  
Tissue Engineering ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Mtt Assay ◽  
Gellan Gum ◽  
Myocardial Tissue ◽  
Oxide Composite ◽  
Reduced Graphene ◽  
Water Swelling

Myocardial infarction is one of the most prevalent diseases around the world. Cardiac tissue engineering is a new approach to repair and revive the structure and functionality of cardiac damaged tissue. In this study, gellan gum/reduced graphene oxide composite hydrogels were fabricated, characterized, and evaluated. The hydrogels were prepared using the solvent casting method and characterized via scanning electron microscopy and Fourier-transform infrared spectroscopy. Compressive mechanical analysis, injectability as well as electrical conductivity test were run. Furthermore, water swelling and degradation analyses were conducted. MTT assay was performed using rat myoblasts (H9C2) to determine the cytotoxicity of our samples. Results showed that reduced graphene oxide fillers dispersed acceptably and enhanced the compressive modulus and electrical conductivity of gellan gum hydrogels. However, in this regard, compressive strength and ductility were not significantly boosted with reduced graphene oxide addition. The water-swelling ratio (%) rised in the presence of reduced graphene oxide, whereas the degradation rate was not significantly affected by them. Meanwhile, synthesized hydrogels showed suitable injectability. MTT assay results revealed that gellan gum hydrogels containing 1% and 2% reduced graphene oxide were not cytotoxic. According to the findings, gellan gum/2% reduced graphene oxide composite hydrogel can be a promising candidate for repairing and healing infarcted myocardial tissue.

scholarly journals Graphene Oxide: A Smart (Starting) Material for Natural Methylxanthines Adsorption and Detection

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4247 ◽  
Author(s):  
Rita Petrucci ◽  
Isabella Chiarotto ◽  
Leonardo Mattiello ◽  
Daniele Passeri ◽  
Marco Rossi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Nucleic Acids ◽  
Reduced Graphene Oxide ◽  
Electrochemical Sensors ◽  
Enzymatic Digestion ◽  
Biologically Active ◽  
Polar Solvents ◽  
Dna And Rna ◽  
Reduced Graphene

Natural methylxanthines, caffeine, theophylline and theobromine, are widespread biologically active alkaloids in human nutrition, found mainly in beverages (coffee, tea, cocoa, energy drinks, etc.). Their detection is thus of extreme importance, and many studies are devoted to this topic. During the last decade, graphene oxide (GO) and reduced graphene oxide (RGO) gained popularity as constituents of sensors (chemical, electrochemical and biosensors) for methylxanthines. The main advantages of GO and RGO with respect to graphene are the easiness and cheapness of synthesis, the notable higher solubility in polar solvents (water, among others), and the higher reactivity towards these targets (mainly due to – interactions); one of the main disadvantages is the lower electrical conductivity, especially when using them in electrochemical sensors. Nonetheless, their use in sensors is becoming more and more common, with the obtainment of very good results in terms of selectivity and sensitivity (up to 5.4 × 10−10 mol L−1 and 1.8 × 10−9 mol L−1 for caffeine and theophylline, respectively). Moreover, the ability of GO to protect DNA and RNA from enzymatic digestion renders it one of the best candidates for biosensors based on these nucleic acids. This is an up-to-date review of the use of GO and RGO in sensors.

Synthesis and characterization of reduced graphene oxide by cobalt oxide composite electrode

2020 ◽  
Author(s):  
S. Veeresh ◽  
H. Ganesh ◽  
Y. S. Nagaraj ◽  
M. Vandana ◽  
S. P. Ashokkumar ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Cobalt Oxide ◽  
Composite Electrode ◽  
Synthesis And Characterization ◽  
Oxide Composite ◽  
Reduced Graphene
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