The kinetic and thermodynamic analysis of Li+ in multi-walled carbon nanotubes

2004 ◽  
Vol 835 ◽  
Author(s):  
Kezhi Lin ◽  
Yanhui Xu ◽  
Xiaolin Wang
Keyword(s):  
Carbon Nanotubes ◽  
Diffusion Coefficient ◽  
Carbon Materials ◽  
Reversible Capacity ◽  
Electrochemical Intercalation ◽  
Different Types ◽  
Multi Walled Carbon Nanotubes ◽  
Kinetic And Thermodynamic Analysis ◽  
Walled Carbon Nanotubes ◽  
Electrochemical Intercalation Reaction

AbstractThe multi-walled carbon nanotubes (MWNTs) prepared by CVD were used in electrochemical intercalation reaction with Li+. The results of the first several charge-discharge cycles showed that the reversible capacity of the MWNTs was larger than the theoretical capacity of graphitized carbon. The equivalent circuit of the Li+ intercalated into the MWNTs was simulated The diffusion coefficient calculated based on the results of the impedance was in the range between 1 ∼ 4×10−10 cm2s−1. The diffusion coefficient calculated based on the technique of the chronoamperometery was 3.5×10−10 cm2s−1. The diffusion coefficients of the Li+ reacted with MWNTs was in the range of that of the most carbon materials. Using EMF method the partial molar entropy (ΔSx) and partial molar enthalpy (ΔHx) of the Li+ intercalated into the MWNTs were calculated as a function of × in Lix C6 at different temperatures. The values of ΔSx were in the range of 150 ∼ 550 J mol-1K-1. The values of ΔHx at 35 °C were in the range of 40∼110 kJ mol−1. Both of the ΔSx and ΔHx were lower and the changes were smaller than the values of some other carbonaceous materials. By analyzing the results conclusion is obtained that Li+ exist in MWNTs with different types which include adsorption and intercalation types.

scholarly journals Electrodeposition of Sn and Sn Composites with Carbon Materials Using Choline Chloride-Based Ionic Liquids

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 798
Author(s):  
Ana T. S. C. Brandão ◽  
Liana Anicai ◽  
Oana Andreea Lazar ◽  
Sabrina Rosoiu ◽  
Aida Pantazi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Materials ◽  
Electrochemical Impedance ◽  
Choline Chloride ◽  
Composite Films ◽  
Growth Stages ◽  
Initial Growth ◽  
Sem Images ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Nano carbons, such as graphene and carbon nanotubes, show very interesting electrochemical properties and are becoming a focus of interest in many areas, including electrodeposition of carbon–metal composites for battery application. The aim of this study was to incorporate carbon materials (namely oxidized multi-walled carbon nanotubes (ox-MWCNT), pristine multi-walled carbon nanotubes (P-MWCNT), and reduced graphene oxide (rGO)) into a metallic tin matrix. Formation of the carbon–tin composite materials was achieved by electrodeposition from a choline chloride-based ionic solvent. The different structures and treatments of the carbon materials will create metallic composites with different characteristics. The electrochemical characterization of Sn and Sn composites was performed using chronoamperometry, potentiometry, electrochemical impedance, and cyclic voltammetry. The initial growth stages of Sn and Sn composites were characterized by a glassy-carbon (GC) electrode surface. Nucleation studies were carried out, and the effect of the carbon materials was characterized using the Scharifker and Hills (SH) and Scharifker and Mostany (SM) models. Through a non-linear fitting method, it was shown that the nucleation of Sn and Sn composites on a GC surface occurred through a 3D instantaneous process with growth controlled by diffusion. According to Raman and XRD analysis, carbon materials were successfully incorporated at the Sn matrix. AFM and SEM images showed that the carbon incorporation influences the coverage of the surface as well as the size and shape of the agglomerate. From the analysis of the corrosion tests, it is possible to say that Sn-composite films exhibit a comparable or slightly better corrosion performance as compared to pure Sn films.

Biosensors for Food Toxin Detection: Carbon Nanotubes and Graphene

2015 ◽  
Vol 1725 ◽  
Author(s):  
Bansi D. Malhotra ◽  
Saurabh Srivastava ◽  
Shine Augustine
Keyword(s):  
Carbon Nanotubes ◽  
Early Detection ◽  
Electrochemical Properties ◽  
Carbon Materials ◽  
Electrochemical Biosensor ◽  
Food Contamination ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Based Nanomaterials ◽  
Food Toxin ◽  
Walled Carbon Nanotubes

ABSTRACTThere is increased interest towards the application of carbon based nanomaterials to biosensors since these can be used to quickly detect presence of the toxins in food, agricultural and environmental systems. The accurate, faster and early detection of food toxins is presently very important for ensuring safety and shelf life of agricultural commodities resulting from food contamination. The carbon materials (CNTs) and recently discovered graphene have been predicted to be promising candidates in the development of electrochemical biosensor owing to their exceptionally large surface area and interesting electrochemical properties. We focus on some of the recent results obtained in our laboratories pertaining to the development of biosensors based on multi-walled carbon nanotubes and graphene for mycotoxin(aflatoxin ) detection.

scholarly journals Multi-walled carbon nanotube doped PVA membrane for desalination

2018 ◽  
Vol 19 (4) ◽  
pp. 1229-1237 ◽  
Author(s):  
B. Yilman ◽  
F. U. Nigiz ◽  
A. Aytaç ◽  
N. D. Hilmioglu
Keyword(s):  
Carbon Nanotubes ◽  
Sem Analysis ◽  
Multi Walled Carbon Nanotube ◽  
Mwcnt Concentration ◽  
Degree Of Swelling ◽  
Excess Amount ◽  
Different Types ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Abstract In this study, multi-walled carbon nanotubes (MWCNT) loaded polyvinyl alcohol (PVA) membranes were synthesized and applied for desalination by means of pervaporation technique. Membranes were characterized using scanning electron microscope (SEM). Sorption studies were carried out to determine the degree of swelling of the MWCNT/PVA membranes into different types of salt solution. Pervaporation experiments were carried using the pristine and MWCNT loaded membranes. The effect of MWCNT concentration and salt concentration on the swelling, flux and salt rejection were investigated at the constant temperature of 40 °C. As a result, greater than 92% of rejections were obtained using all membrane. The highest flux was obtained using 0.3 wt% MWCNT loaded membrane with the highest rejection of 98.8%. SEM analysis confirmed that the excess amount of particles caused agglomeration and negatively affected the desalination performance.

Fabrication and Properties of Multi-Walled Carbon Nanotubes Buckypaper

2015 ◽  
Vol 1108 ◽  
pp. 33-38 ◽  
Author(s):  
W.A.D. Wan Dalina ◽  
M. Mariatti ◽  
Soon Huat Tan ◽  
Z.A. Mohd Ishak ◽  
Abdul Rahman Mohamed
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
High Performance ◽  
Free Standing ◽  
Filtration Process ◽  
Different Types ◽  
Multi Walled Carbon Nanotubes ◽  
Triton X ◽  
Walled Carbon Nanotubes

Free-standing carbon nanotubes (CNTs) film known as buckypaper is a method used to address dispersion problems of CNTs. Unique properties of CNTs made the CNTs buckypaper to be considered as promising reinforcement materials in development of high-performance of nanocomposites. Buckypaper was fabricated by dispersing multi-walled carbon nanotubes (MWCNTs) in two different types of solution namely Triton X-100 and ethanol then followed by filtration process. In this study, MWCNTs loading and pressure used during filtration process were manipulated. The morphology, thermal and electrical conductivity of the buckypaper produced was studied.

Effect of Multi Walled Carbon Nanotubes Incorporated on Refractory Castables

2016 ◽  
Vol 881 ◽  
pp. 475-480
Author(s):  
Norval Rodrigues de Oliveira Jr. ◽  
Fabíola A.S. Ribeiro ◽  
Gustavo C. Salles ◽  
Clascídia A. Furtado ◽  
Modestino A. Brito ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Modulus Of Rupture ◽  
Outer Diameter ◽  
Water Addition ◽  
Refractory Castables ◽  
Mwcnt Concentration ◽  
Different Types ◽  
Negative Effect ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Two different types of multi walled carbon nanotubes (MWCNT) were introduced in a calcium aluminate refractory castable used in steelmaking process. The first MWCNT was purchased from Cheap Tubes (USA), a hydroxyl (-OH) functionalized, outer diameter of 50-80 nm, length of 10-20 μm, and, the second one was supplied by Nanocyl (Belgium), not functionalized, outer diameter of 9.5 nm, and length of 1.5 μm. Both types of MWCNT were incorporated into the dry castable mixture before water addition. The workability and properties of the final product, such as apparent density, apparent porosity and hot modulus of rupture were evaluated. The nanocarbons were characterized by SEM, TEM, TGA and Raman spectroscopy. In both cases, the incorporation of MWCNT had a negative effect on the rheology of wet castables, decreasing their workability. No significant improvements on mechanical properties of the castables were observed with the incorporation until MWCNT concentration reached 0.15 % (m/m), except for the increase of hot modulus of rupture observed for Cheap Tubes MWCNT introduction.

scholarly journals Polycondensation of Hexamethylenetetramine in Anhydrous Acid Media as a New Approach to Carbyne-Like Materials and Its Application as Dispersant of Carbon Materials

2019 ◽  
Vol 5 (3) ◽  
pp. 54
Author(s):  
Alyona V. Gerasimova ◽  
Olga V. Alekhina ◽  
Leticia García-Cruz ◽  
Jesús Iniesta ◽  
Alexander V. Melezhik ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Spectral Properties ◽  
High Performance ◽  
Carbon Materials ◽  
Acid Media ◽  
New Approach ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Aminocumulene (AC), a technical name that results from the hexamethylenetetramine polycondensation in anhydrous sulfuric acid, was successfully performed toward the synthesis of oligomeric cumulenic compounds made up of carbyne-like (=C=C)x fragments as a main moiety together with amino endcapping groups. The tentative mechanism for the synthesis of the soluble and insoluble AC likely included the participation of carbene species as an intermediate. Spectral properties obtained from UV-Vis, infrared, and Raman spectroscopies, and surface chemistry analysis through X-ray photoelectron spectroscopy of the soluble AC confirmed the presence of a mixture of linear and branched aminocumulene-based oligomers. AC displayed high performance as a dispersant and stabilizer agent of both multi-walled carbon nanotubes and graphene in aqueous solutions after powerful insonation treatment under controlled temperature compared to the most commonly used dispersant agents. Thereby, AC is vitally important for the preparation of carbonaceous materials based on nanoinks in a wide variety of fields.

Conductivity Modification of Carbon-Based Nanocomposites

2018 ◽  
Vol 879 ◽  
pp. 41-46
Author(s):  
Theerapol Thurakitseree ◽  
Wilaiwan Leenakul
Keyword(s):  
Carbon Nanotubes ◽  
Electron Transfer ◽  
Thermal Properties ◽  
Polyvinyl Chloride ◽  
Chemical Process ◽  
Carbon Materials ◽  
Electrical Conductivities ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Thermal Conductivities

The combination of carbon materials and polymer has been well studied according to their compatable mixture in polymer with promising properties. Due to their excellent electrical and thermal properties for some types of carbons such as carbon nanotubes and graphite, they have been selected as component for nanocomposites. Here, capability of multi-walled carbon nanotubes (MWNTs) and graphite for nanocomposites were demonstrated. Nanotubes were functionalized by chemical process, and added into polyvinyl chloride (PVA) matrix. They were then used as main filler to modify thermal and electrical conductivities. Conductivities of different composite mixtures were finally investigated. With the use of low total amount of carbon materials, it was found that although there is no significant change in electrical and thermal conductivities, the highest conductivities could be obtained from MWNT to graphite ratio of 1:1 in PVA matrix, while the G-band mode does not give a rise to electron transfer.

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