scholarly journals ELECTROPHYSICAL PROPERTIES OF ZINC SULFATE SOLUTIONS IN PRESENCE OF WATER DISPERSION OF MULTI-LAYERED CARBON NANOTUBES

2018 ◽  
Vol 61 (12) ◽  
pp. 115-121
Author(s):  
Evgeniy S. Vavilov ◽  
Alexandr I. Biryukov ◽  
Igor N. Kovalev ◽  
Alexandr V. Tolchev
Keyword(s):  
Carbon Nanotubes ◽  
Zinc Sulfate ◽  
Carbon Nanomaterials ◽  
Reaction System ◽  
Electrophysical Properties ◽  
Electron Conduction ◽  
Sulfate Solutions ◽  
Zinc Electrolyte ◽  
Ph Level ◽  
Solution Changes

Multi-layered carbon nanotubes were synthesized via hydrocarbons pyrolysis method in the presence of argon overpressure in the reaction system. With the use of the scanning electron microscope method, a morphology of the obtained materials were investigated. Synthetized nanotubes were modified by treating with solutions of various reagents: sodium hydroxide (10 mass. %), azotic (40 mass. %) and perchloric (40 mass. %) acids, chloroform. The sample was placed in the reagent solution with the volume of 10 ml and exposed for 24 h. Electrophysical investigation of multi-layered carbon nanotubes dispersions with zinc sulfate additions was carried with the use of the impedance meter Z - 1500J in a range of frequencies of 10 Hz - 2 MHz. It was found that the carbon nanomaterials effect on the electrophysical properties of zinc electrolyte. A change in electrical conductivity of zinc sulfate solutions with the addition of multi-layered carbon nanotubes with various morphology and surface modifications was studied. With the use of impedance spectroscopy method, there were examined the electrophysical properties of zinc electrolyte with additions of carbon nanotubes in the presence of various components concentration and pH level of the environment, that was obtained via the original technique. It is shown that electron conduction increases with the rise of nanotubes concentration, but substantially levels with the rise of zinc sulfate concentration. Moreover, insertion of multi-layered carbon nanotubes in the solution changes a state of equivalent circuit and its elements. It is concluded that insert of multi-layered carbon nanotubes has unambiguous impact on the electrophysical properties of zinc sulfate solutions. Based on the obtained data, a scheme of electrolyte and nanotubes interaction is offered.  

Separation of Cobalt from Zinc Sulfate Solution by Novel Oxidant

2011 ◽  
Vol 695 ◽  
pp. 145-148 ◽  
Author(s):  
Lin Bo Li ◽  
Juan Qin Xue ◽  
Tao Hong ◽  
Jun Yang ◽  
Xing Wang
Keyword(s):  
Zinc Sulfate ◽  
Sulfate Solution ◽  
Xrd Analysis ◽  
Cobalt Hydroxide ◽  
Precipitation Process ◽  
Optimal Parameters ◽  
Pure Cobalt ◽  
Sulfate Solutions ◽  
Zinc Electrolyte ◽  
Cobaltosic Oxide

The separation of cobalt from zinc sulfate solutions by oxidation-precipitation process using peroxy-monosulfuric acid as oxidant has been presented according to the technological conditions of removal of cobalt from zinc electrolyte. After investigating the important parameters governing the separation of cobalt and their effect on the separation process, the optimal parameters of oxidation precipitation of cobalt were determined, the oxidation precipitation percent of cobalt was up to 90% under the conditions. The XRD analysis results of precipitates demonstrated that the precipitate was cobalt hydroxide oxide (CoOOH) in pure cobalt system while the precipitates were cobaltosic oxide (Co3O4) and basic zinc sulfate (ZnSO4(OH)6.H2O) in zinc-cobalt system.

scholarly journals Autoclave Precipitation Of Iron From Zinc Sulfate Solutions

2017 ◽  
Vol 2 (2) ◽  
pp. 76
Author(s):  
K.A. Karimov ◽  
A.V. Kritskii ◽  
S.S. Naboichenko ◽  
O.B. Kolmachikhina ◽  
D.A. Rogozhnikov
Keyword(s):  
Zinc Sulfate ◽  
High Sensitivity ◽  
Negative Influence ◽  
Model Solution ◽  
Pressure Leaching ◽  
Optimum Conditions ◽  
Iron Precipitation ◽  
Sulfate Solutions ◽  
Zinc Electrolyte

<p>Zinc concentrates processing technology that includes high-temperature roasting – leaching of cinder – purification of leached liquor – electrowinning is the most widely used technology. Purified solution, which is fed to the electrowinning stage, has a high sensitivity to such an impurity as iron. The presence of iron in the zinc electrolyte has a negative influence both on the current efficiency and the quality of the cathode zinc. </p><p>The application of autoclave equipment for iron removal from zinc sulfate solutions, obtained after the leaching stage of zinc cinder, is described in this article. All experiments were carried out with a model solution of following composition, g/L: 10-33 H<sub>2</sub>SO<sub>4</sub>, 1.5 Cu, 5 Mn, 110 Zn, 2.5 Fe. Neutralization and purification of the solution was implemented during low-temperature pressure leaching of the zinc cinder. </p><p>The optimum conditions for iron precipitation from zinc solution are following: molar flow rate Zn(cinder) / H<sub>2</sub>SO<sub>4</sub> = 1.3, t = 80 °C, τ = 1 hour, P<sub>O2</sub> = 0.2 MPa. It was found, that the concentration of iron can be reduced up to 1-2 mg/L, whereas 83.5% of Zn and 52.1% of Cu being recovered into the solution from zinc cinder.</p>

scholarly journals N-Dopant-Mediated Growth of Metal Oxide Nanoparticles on Carbon Nanotubes

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1882
Author(s):  
Jin Ah Lee ◽  
Won Jun Lee ◽  
Joonwon Lim ◽  
Sang Ouk Kim
Keyword(s):  
Carbon Nanotubes ◽  
Metal Oxide ◽  
Carbon Nanomaterials ◽  
Wide Spectrum ◽  
Metal Oxide Nanoparticles ◽  
Nucleation And Growth ◽  
Oxide Nanoparticles ◽  
Metal Oxide Nanoparticle ◽  
Nucleation Sites ◽  
Direct Growth

Metal oxide nanoparticles supported on heteroatom-doped graphitic surfaces have been pursued for several decades for a wide spectrum of applications. Despite extensive research on functional metal oxide nanoparticle/doped carbon nanomaterial hybrids, the role of the heteroatom dopant in the hybridization process of doped carbon nanomaterials has been overlooked. Here, the direct growth of MnOx and RuOx nanoparticles in nitrogen (N)-doped sites of carbon nanotubes (NCNTs) is presented. The quaternary nitrogen (NQ) sites of CNTs actively participate in the nucleation and growth of the metal nanoparticles. The evenly distributed NQ nucleation sites mediate the generation of uniformly dispersed <10 nm diameter MnOx and RuOx nanoparticles, directly decorated on NCNT surfaces. The electrochemical performance of the resultant hybridized materials was evaluated using cyclic voltammetry. This novel hybridization method using the dopant-mediated nucleation and growth of metal oxides suggests ways that heteroatom dopants can be utilized to optimize the structure, interface and corresponding properties of graphitic carbon-based hybrid materials.

Fullerene Derivatives (CN-[OH]β) and Carbon Nanotubes Modelled as Transporters for Doxorubicin Drug in Cancer Therapy

2021 ◽  
Author(s):  
Hakim AL Garalleh
Keyword(s):  
Carbon Nanotubes ◽  
Anticancer Drugs ◽  
Carbon Nanomaterials ◽  
Aqueous Media ◽  
Medical Model ◽  
Antitumor Agent ◽  
World Health ◽  
Fullerene Derivative ◽  
Fullerene Derivatives ◽  
Health Organization

Abstract Carbon nanomaterials have received increasing attention in drug delivery applications because of their distinct properties and structures, including large surface areas, high conductivity, low solubility in aqueous media, unique chemical functionalities and stability at the nano-scale size. Particularly, they have been used as nano-carriers and mediators for anticancer drugs such as, combination with Cisplatin, Camptothecin and Doxorubicin. Cancer has become the most challenging disease because its sophisticated therapy and classified as one of the top killers according to the World health organization records. The aim of the current work is to study and investigate the mechanism of combination between single-walled carbon nanotubes (SWCNTs) and the fullerene derivatives (C N -[OH] β ) as mediators, and anticancer drugs for photodynamic therapy directly to destroy the infected cells without damaging the normal ones. Here, we obtain a bio-medical model to determine the efficiency of usefulness of Doxorubicin (DOX) as an antitumor agent conjugated with SWCNTs with variant radii r and fullerene derivative (C N -[OH] β ). The two sub-models are obtained mathematically to evaluate the potential energy arising from the DOX-SWCNT and DOX-(C N -[OH] β ) interactions. DOX modelled as two-connected spheres, small and large, each interacting with different SWCNTs (variant radii r ) and fullerene derivatives C N -[OH] β , forming based on the number of carbon atoms (N) and the number of Hydroxide molecules (OH) ( β ), respectively.

scholarly journals Thermodynamics and Kinetic Modeling of the ZnSO4.H2O Thermal Decomposition in the Presence of a Pd/Al2O3 Catalyst

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 548
Author(s):  
Gabriela V. T. Kurban ◽  
Artur S. C. Rego ◽  
Nathalli M. Mello ◽  
Eduardo A. Brocchi ◽  
Rogério C. S. Navarro ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Zinc Sulfate ◽  
Thermodynamic Assessment ◽  
Reaction System ◽  
Decomposition Temperature ◽  
Kinetic Behavior ◽  
Proposed Model ◽  
Al2o3 Catalyst ◽  
Iodine Reaction

The sulfur–iodine thermochemical water-splitting cycle is a promising route proposed for hydrogen production. The decomposition temperature remains a challenge in the process. Catalysts, such as Pd supported on Al2O3, are being considered to decrease reaction temperatures. However, little is known regarding the kinetic behavior of such systems. In this work, zinc sulfate thermal decomposition was studied through non-isothermal thermogravimetric analysis to understand the effect of a catalyst within the sulfur–iodine reaction system context. The findings of this analysis were also related to a thermodynamic assessment. It was observed that the presence of Pd/Al2O3 modified the reaction mechanism, possibly with some intermediate reactions that were suppressed or remarkably accelerated. The proposed model suggests that zinc sulfate transformation occurred in two sequential stages without the Pd-based material. Activation energy values of 238 and 368 kJ.mol−1 were calculated. In the presence of Pd/Al2O3, an activation energy value of 204 kJ.mol−1 was calculated, which is lower than observed previously.

scholarly journals Application of Carbon Nanomaterials Decorated Electrochemical Sensor for Analysis of Environmental Pollutants

2021 ◽  
Author(s):  
Sunil Kumar ◽  
Abhay Nanda Srivastva
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanomaterials ◽  
Electrochemical Sensors ◽  
Anodic Stripping Voltammetry ◽  
Environmental Pollutants ◽  
Stripping Voltammetry ◽  
Metal Electrode ◽  
Effective Area ◽  
Electrochemical Sensing ◽  
Working Electrode

Carbon nanomaterials (CNMs), especially carbon nanotubes and graphene, have been attracting tremendous attention in environmental analysis for rapid and cost effective detection of various analytes by electrochemical sensing. CNMs can increase the electrode effective area, enhance the electron transfer rate between the electrode and analytes, and/or act as catalysts to increase the efficiency of electrochemical reaction, detection, adsorption and removal are of great significance. Various carbon nanomaterials including carbon nanotubes, graphene, mesoporous carbon, carbon dots exhibited high adsorption and detection capacity. Carbon and its derivatives possess excellent electro catalytic properties for the modified sensors, electrochemical methods usually based on anodic stripping voltammetry at some modified carbon electrodes. Metal electrode detection sensitivity is enhanced through surface modification of working electrode (GCE). Heavy metals have the defined redox potential. A remarkable deal of efficiency with the electrochemical sensors can be succeeded by layering the surface of the working electrode with film of active electro-catalytic species. Usually, electro catalysts used for fabrication of sensors are surfactants, nano-materials, polymers, carbon-based materials, organic ligands and biomaterials.

scholarly journals Preparation of Bulk13C-Enriched Graphene Materials

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Leilei Tian ◽  
Xin Wang ◽  
Li Cao ◽  
Mohammed J. Meziani ◽  
Chang Yi Kong ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Convenient Method ◽  
Carbon Nanomaterials ◽  
Arc Discharge ◽  
Single Walled Carbon Nanotubes ◽  
Production Technique ◽  
Graphene Oxides ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Bulk Production

Arc-discharge has been widely used in the bulk production of various carbon nanomaterials, especially for structurally more robust single-walled carbon nanotubes. In this paper, the same bulk-production technique was applied to the synthesis of significantly13C-enriched graphitic materials, from which graphene oxides similarly enriched with13C were prepared and characterized. The results demonstrate that arc-discharge is a convenient method to produce bulk quantities of13C-enriched graphene materials from relatively less expensive precursors (largely amorphous13C powders).

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