scholarly journals Thermal Conductivity of Polyimide/Carbon Nanofiller Blends

2007 ◽  
Vol 334-335 ◽  
pp. 749-752 ◽  
Author(s):  
Subrata Ghose ◽  
K.A. Watson ◽  
D.M. Delozier ◽  
D.C. Working ◽  
John W. Connell ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Tensile Testing ◽  
Expanded Graphite ◽  
Multiwalled Carbon ◽  
Carbon Nanofiller ◽  
Scanning Electron

In efforts to improve the thermal conductivity (TC) of Ultem™ 1000, it was compounded with three carbon based nano-fillers. Multiwalled carbon nanotubes (MWCNT), vapor grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. Ribbons were extruded to form samples in which the nano-fillers were aligned. Samples were fabricated by compression molding where the nano-fillers were randomly oriented. The thermal properties were evaluated by DSC and TGA, and the mechanical properties of the aligned samples were determined by tensile testing. The degree of dispersion and alignment of the nanoparticles were investigated with high-resolution scanning electron microscopy. The thermal conductivity was measured in two directions using the Nanoflash technique.

scholarly journals Polymeric Composites Based on Polyurea Matrix Reinforced with Carbon Nanotubes

2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.

scholarly journals Surface Properties of Silica–MWCNTs/PDMS Composite Coatings Deposited on Plasma Activated Glass Supports

2021 ◽  
Vol 11 (19) ◽  
pp. 9256
Author(s):  
Michał Chodkowski ◽  
Iryna Ya. Sulym ◽  
Konrad Terpiłowski ◽  
Dariusz Sternik
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Composite Coatings ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Visible Range ◽  
Multiwalled Carbon ◽  
Scanning Electron

In this paper, we focus on fabrication and physicochemical properties investigations of silica–multiwalled carbon nanotubes/poly(dimethylsiloxane) composite coatings deposited on the glass supports activated by cold plasma. Air or argon was used as the carrier gas in the plasma process. Multiwalled carbon nanotubes were modified with poly(dimethylsiloxane) in order to impart their hydrophobicity. The silica–multiwalled carbon nanotubes/poly(dimethylsiloxane) nanocomposite was synthesized using the sol–gel technique with acid-assisted tetraethyl orthosilicate hydrolysis. The stability and the zeta potential of the obtained suspension were evaluated. Then, the product was dried and used as a filler in another sol–gel process, which led to the coating application via the dip-coating method. The substrates were exposed to the hexamethyldisilazane vapors in order to improve their hydrophobicity. The obtained surfaces were characterized by the wettability measurements and surface free energy determination as well as optical profilometry, scanning electron microscopy, and transmittance measurements. In addition, the thermal analyses of the carbon nanotubes as well as coatings were made. It was found that rough and hydrophobic coatings were obtained with a high transmittance in the visible range. They are characterized by the water contact angle larger than 90 degrees and the transmission at the level of 95%. The X-ray diffraction studies as well as scanning electron microscopy images confirmed the chemical and structural compositions of the coatings. They are thermally stable at the temperature up to 250 °C. Moreover, the thermal analysis showed that the obtained composite material has greater thermal resistance than the pure nanotubes.

Evaluation of 4330M Steel for Fasteners Applications

2017 ◽  
Vol 380 ◽  
pp. 198-211 ◽  
Author(s):  
A. Al Sumait ◽  
C. Delgado ◽  
F. Aldhabib ◽  
X. Sun ◽  
F. Alzubi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Testing ◽  
Grain Structure ◽  
Hardness Testing ◽  
Heat Treated ◽  
Different Types ◽  
Strength And Ductility ◽  
Scanning Electron

The objective of the study was to optimize the strength and ductility values of the 4330M steel. Optimization was conducted through different types of heat treatments. Tensile testing, hardness testing, optical microscopy, and Scanning Electron Microscopy (SEM) were used to evaluate the mechanical properties and microstructure of the as-received and the heat treated samples. The alloy was provided from two vendors; vendor H and vendor S. Results showed that by increasing the tempering temperatures, strength values decreases, while ductility values remain unchanged. Vendor H samples had higher strength values and much finer grain structure which was revealed only at 5000x magnification.

Morphology and thermal properties of nanocomposites based on chiral poly(ester-imide) matrix reinforced by vitamin B1 functionalized multiwalled carbon nanotubes

2016 ◽  
Vol 51 (16) ◽  
pp. 2291-2300 ◽  
Author(s):  
Shadpour Mallakpour ◽  
Samaneh Soltanian
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Vitamin B1 ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Scanning Electron

Chemical functionalization of carboxylated multiwalled carbon nanotubes with vitamin B1 was carried out under ultrasonic irradiation. The functionalized nanotubes were embedded in a chiral and biodegradable poly(ester-imide) to prepare multiwalled carbon nanotubes reinforced polymer nanocomposites. Optically active poly(ester-imide) was synthesized by step-growth polymerization of aromatic diol and amino acid based diacid. The vitamin B1 functionalized multiwalled carbon nanotubes and the resulting nanocomposites were examined using Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, transmission electron microscopy, and field-emission scanning electron microscopy. Thermogravimetric analysis results indicated that temperature at 10% weight loss was increased from 409℃ for pure PEI to 419℃, 427℃, and 430℃ for nanocomposites containing 5%, 10%, and 15% functionalized multiwalled carbon nanotubes, respectively. The Fourier-transform scanning electron microscopy and transmission electron microscopy images exhibited that the functionalized multiwalled carbon nanotubes were separated individually and enwrapped by polymer chains.

scholarly journals Influence of Processing Method on the Mechanical and Electrical Properties of MWCNT/PET Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
O. Rodríguez-Uicab ◽  
A. May-Pat ◽  
F. Avilés ◽  
P. Toro ◽  
M. Yazdani-Pedram
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Processing Method ◽  
Multiwalled Carbon ◽  
Electrical Percolation ◽  
Melt Compounding ◽  
Mechanical And Electrical Properties ◽  
Electrical Percolation Threshold ◽  
Scanning Electron

Multiwalled carbon nanotube (MWCNT)/polyethylene terephthalate (PET) composites were prepared by three processing methods: direct extrusion (DE), melt compounding followed by extrusion (MCE), and dispersion of the MWCNTs in a solvent by sonication followed by extrusion (SSE). The mechanical properties of the MWCNT/PET composites processed by MCE increased with 0.1 wt% MWCNTs with respect to the neat PET. The electrical percolation threshold of MWCNT/PET composites processed by DE and MCE was ~1 wt% and the conductivity was higher for composites processed by MCE. Raman spectroscopy and scanning electron microscopy showed that mixing the MWCNTs by melt compounding before extruding yields better dispersion of the MWCNTs within the PET matrix. The processing method assisted by a solvent resulted in matrix plasticization.

Self-Assembly of Aligned Multi-Walled Carbon Nanotubes in Polypropylene-Coated Multi-Walled Carbon Nanotubes Composites

2013 ◽  
Vol 669 ◽  
pp. 55-62 ◽  
Author(s):  
Yi Na Xiong ◽  
Xiao Hua Chen ◽  
Qun Huang ◽  
Long Shan Xu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Self Assembly ◽  
Butyl Methacrylate ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Polypropylene (PP)-coated multi-walled carbon nanotubes (MWNTs) composite with MWNTs exceptional alignment dispersed and improved mechanical properties was prepared with maleic anhydride (MAH) as a compatibilizer and poly (butyl methacrylate) (PBMA) as a binding. Scanning electron microscopy (SEM) results showed that MWNTs within composite were aligned without aggregation and the oriented MWNTs were connected by matrix. High-resolution transmission electron microscopy (HRTEM) results demonstrated that the nanotubes were densely coated with a PP layer. Infrared spectroscopy (IR) results revealed that there was covalently linkage of MWNTs with PP via MAH. The interactions between MWNTs-PP and MWNTs-PBMA induced orientation of MWNTs. The improved mechanical properties of PP - coated MWNTs composite was also shown.

Effect of B Refinement on Structure and Fracture Morphology of Al-7 wt.% Si Alloy

2014 ◽  
Vol 590 ◽  
pp. 181-186
Author(s):  
Xiao Song Li ◽  
An Hui Cai ◽  
Ji Jie Zeng
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Testing ◽  
Testing Machine ◽  
Fracture Morphology ◽  
Optical Microscope ◽  
Tensile Testing Machine ◽  
Alloy Microstructure ◽  
Scanning Electron

Using optical microscope, electronic tensile testing machine, scanning electron microscopy methods, such as detailed treatment of the B hypoeutectic Al-Si alloy microstructure, mechanical properties and fracture morphology were studied. The results showed that after treatment by the B refinement, α-Al dendrite phase was refined, resulting in mechanical properties of Al-Si alloy significantly improved. Which, B content 0.036wt.%, the alloy the best, the σb, δ, respectively, than the non-thinning increased 67.8% and 15.2%. From the fracture surface, the fracture morphology of the specimen showed a quasi-cleavage fracture. Which, B content 0.036wt.% at the time of fracture is more deep dimples, and a good plastic toughness.

MWCNTs-polymer composites characterization through spectroscopies: FTIR and Raman

MRS Advances ◽  
2018 ◽  
Vol 3 (63) ◽  
pp. 3757-3762 ◽  
Author(s):  
Francisco G. Granados-Martínez ◽  
José J. Contreras-Navarrete ◽  
Jael M. Ambriz-Torres ◽  
Carmen J. Gutiérrez-García ◽  
Diana L. García-Ruiz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Polymer Composites ◽  
Multiwalled Carbon Nanotubes ◽  
Polymethyl Methacrylate ◽  
Multiwalled Carbon ◽  
Polymeric Matrices ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Scanning Electron

ABSTRACTComposites from carbon nanotubes and polymers have been synthesized and studied. The composites were obtained joining carbon nanotubes with polymethyl methacrylate, nylon-6 and polystyrene. The materials were observed through scanning electron microscopy to evaluate the carbon nanotubes dispersion in the polymeric matrices. FTIR and Raman spectroscopies were used to analyze the interactions among functionalized and non-functionalized multiwalled carbon nanotubes and polymers, demonstrating affinity and peculiar spectra behaviors for each composite with different carbon nanotubes loads.

Enhanced Electrical Properties of Fly Ash Geopolymer Composites with Carbon Nanotubes

2019 ◽  
Vol 296 ◽  
pp. 137-142 ◽  
Author(s):  
Cecílie Mizerová ◽  
Ivo Kusák ◽  
Pavel Rovnaník ◽  
Patrik Bayer
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Fly Ash ◽  
Electrical Properties ◽  
Mercury Intrusion Porosimetry ◽  
Mercury Intrusion ◽  
Geopolymer Composites ◽  
Scanning Electron

Carbon nanotubes (CNTs) are used for the application in concrete especially due to their excellent physical properties. In this study, CNTs were used as a conductive admixture to prepare composites with enhanced electrical properties that might be potentially used in smart concretes or structures. We assessed the changes in selected electrical properties of fly ash geopolymer mortars (conductivity, resistance, capacitance) depending on the concentration of CNTs that ranged from 0.05 to 0.20%. The most convenient CNTs concentration was discussed considering both the electrical and mechanical properties (compressive and flexural strength). Mercury intrusion porosimetry and scanning electron microscopy were used to observe the distribution of CNTs and porosity of the mortars.

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