scholarly journals Thermal Spectroscopy and Kinetic Studies of PEO/PVDF Loaded by Carbon Nanotubes

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Laila Hussein Gaabour
Keyword(s):  
Activation Energy ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Heating Rate ◽  
Polyvinylidene Fluoride ◽  
Kinetic Studies ◽  
Multiwalled Carbon ◽  
Polymeric Matrices ◽  
Swcnts And Mwcnts ◽  
Thermal Stability Of

Nanocomposites of polyethylene oxide (PEO) and polyvinylidene fluoride (PVDF) without and with low content of single and multiwalled carbon nanotubes (SWCNTs-MWCNTs) were prepared and studied by thermogravimetric analysis (TGA) using different heating rate. TGA results indicate that the thermal stability of neat PEO/PVDF blend was improved with both heating rate and incorporation of carbon nanotubes (CNTs). The degradation temperature for neat blend was lower than those of the nanocomposites after adding both SWCNTs and MWCNTs. As increase of heating rate, the onset of decomposition is irregularly moved to higher temperatures. This indicates that the thermal stability of the polymeric matrices has been improved after addition of CNTs. The residual weight of the samples left increased steadily with adding of both SWCNTs and MWCNTs. Kinetic thermodynamic parameters such as activation energy, enthalpy, entropy, and Gibbs free energy are evaluated from TGA data using Coats-Redfern model. The values of all parameters irregularly decrease with increasing of heating rate due to increasing of heating rate temperature, the random scission of macromolecule chain in the polymeric matrices predominates and the activation energy has a lower value.

Towards Long-Term Thermal Stability of Dye-Sensitized Solar Cells Using Multiwalled Carbon Nanotubes

ChemPlusChem ◽  
2018 ◽  
Vol 83 (7) ◽  
pp. 682-690 ◽  
Author(s):  
Mahyar Mohammadnezhad ◽  
Gurpreet Singh Selopal ◽  
Zhiming M. Wang ◽  
Barry Stansfield ◽  
Haiguang Zhao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Solar Cells ◽  
Multiwalled Carbon Nanotubes ◽  
Dye Sensitized Solar Cells ◽  
Multiwalled Carbon ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Thermal Stability Of

An effective and novel approach for enhancement of the oxidative thermal stability of multiwalled carbon nanotubes loaded polymer blend

2019 ◽  
Vol 33 (11) ◽  
pp. 1499-1517
Author(s):  
Mohammad Abu-Abdeen ◽  
Osama Saber ◽  
Javed Mazher ◽  
Mohamed M Ahmed ◽  
Mohamed Gouda
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Thermal Treatment ◽  
Multiwalled Carbon Nanotubes ◽  
Polymer Matrix ◽  
Gravimetric Analysis ◽  
Multiwalled Carbon ◽  
Ac Electrical Conductivity ◽  
Wide Range ◽  
Thermal Stability Of

Multiwalled carbon nanotubes (MWCNTs) have wide range of applications. Commercial MWCNTs have impurities, disorder and entangled structure, which limit its applications. In this respect, novel, low-energy consumption and friendly technique was applied to enhance its structure. The technique is operated during isometric process inside autoclave and based on thermal treatment of MWCNTs in the presence of solvent and pressure. It was used to enhance the oxidative thermal stability of MWCNTs. Thermal gravimetric analysis results showed an increase in onset temperature, activation energy of decomposition, and the temperature required to loss 75, 50, and 33 wt% as the treating temperature increased. Raman spectroscopy tests showed a decrease in the degree of disorder from 1.29 for untreated samples to 0.45 for samples treated at 250°C. The electrical resistivity of MWCNTs was increased from 0.33 Ω.cm for untreated samples to 0.54 Ω cm for 250°C treated samples. Advantages of thermal treatment of MWCNTs using this technique appeared in the presence of a percolation behavior for the AC electrical conductivity when a polymer matrix was loaded with it with a threshold percolation concentration of 0.7 wt%. Furthermore, Cole–Cole Z semicircles as well as Argand plots of the electric modulus appeared for polymer matrix loaded with thermally treated MWCNTs beyond the threshold percolation concentration.

scholarly journals Cover Feature: Towards Long-Term Thermal Stability of Dye-Sensitized Solar Cells Using Multiwalled Carbon Nanotubes (ChemPlusChem 7/2018)

ChemPlusChem ◽  
2018 ◽  
Vol 83 (7) ◽  
pp. 546-546
Author(s):  
Mahyar Mohammadnezhad ◽  
Gurpreet Singh Selopal ◽  
Zhiming M. Wang ◽  
Barry Stansfield ◽  
Haiguang Zhao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Solar Cells ◽  
Multiwalled Carbon Nanotubes ◽  
Dye Sensitized Solar Cells ◽  
Multiwalled Carbon ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Thermal Stability Of

Thermal Stability of Zirconia-coated Multiwalled Carbon Nanotubes

2010 ◽  
Vol 60 (3) ◽  
pp. 337-342 ◽  
Author(s):  
R. Manivannan ◽  
Alex Daniel ◽  
I. Srikanth ◽  
Anil Kumar ◽  
Rajdeep Sarkar ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
Thermal Stability Of

scholarly journals Single- and Multiwalled Carbon Nanotubes with Phosphorus Based Flame Retardants for Textiles

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
D. Wesolek ◽  
W. Gieparda
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Multiwalled Carbon Nanotubes ◽  
Flame Retardants ◽  
Multiwalled Carbon ◽  
Textile Materials ◽  
Flow Calorimeter ◽  
Polyurethane Resin ◽  
Combustion Flow ◽  
Thermal Stability Of

Due to growing popularity of composites, modification methods to obtain the best properties are searched for. The aim of the study is to reduce the flammability of textile materials using nanocomposite polymer back-coating. Different types of carbon nanotubes (single- and multiwalled) and different phosphorus flame retardants (ammonium polyphosphates and melamine polyphosphate) were introduced into the resin and then the fabrics were covered by the obtained composites. Homogeneous dispersion of multiwalled carbon nanotubes in the polyurethane resin was obtained by sonification, which was confirmed by scanning electron microscopy. Flammability tests of fabrics coated by modified polyurethane resin were carried out using pyrolysis combustion flow calorimeter (PCFC) and thermal stability of textiles was evaluated. Also, organoleptic estimation of coatings was conducted (flexibility and fragility). The use of polymer nanocomposites with phophorus flame retardants as a back-coating for textiles effectively reduces flammability and improves thermal stability of the fabric. Furthermore, the synergistic effect beetwen carbon nanotubes and phosphorous compound occurs. The resulting coatings are flexible and do not crack or change the feel of fabrics.

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