MICROSTRUCTURE AND RESISTIVITY OF CARBON NANOTUBE AND NANOFIBER/EPOXY MATRIX NANOCOMPOSITE

2002 ◽  
Vol 01 (05n06) ◽  
pp. 719-723 ◽  
Author(s):  
JIN-HONG DU ◽  
ZHE YING ◽  
SHUO BAI ◽  
FENG LI ◽  
CHAO SUN ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Epoxy Matrix ◽  
Single Walled Carbon Nanotubes ◽  
Epoxy Nanocomposites ◽  
Multiwalled Carbon ◽  
Pure Epoxy ◽  
The Matrix ◽  
Walled Carbon Nanotubes ◽  
Matrix Nanocomposites ◽  
Matrix Nanocomposite

Single-walled carbon nanotubes (SWNTs), multiwalled carbon nanotubes (MWNTs) and vapor-grown carbon nanofibers (VGCNFs)/epoxy matrix nanocomposites were prepared, respectively. The microstructure of the nanocomposites was observed by SEM and the resistivities of the nanocomposites with different concentration of CNTs/VGCNFs were measured. Based on the experimental results, the dispersion of SWNTs and MWNTs were relatively poor but that of VGCNFs is uniform within the matrix. The resistivitiy of pure epoxy is about 1010.5Ω · cm and several orders of magnitude higher than those of SWNT, MWNT and VGCNF/epoxy nanocomposites. The resistivities of the nanocomposites drop with the increase of the CNTs/VGCNFs content in the matrix and the resistivity of VGCNFs/epoxy nanocomposites was much lower than that of CNT/epoxy nanocomposites.

scholarly journals Dragging Human Mesenchymal Stem Cells with the Aid of Supramolecular Assemblies of Single-Walled Carbon Nanotubes, Molecular Magnets, and Peptides in a Magnetic Field

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Ana Cláudia C. de Paula ◽  
Gustavo A. M. Sáfar ◽  
Alfredo M. Góes ◽  
Marcelo P. Bemquerer ◽  
Marcos A. Ribeiro ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Stem Cells ◽  
Supramolecular Assembly ◽  
Single Walled Carbon Nanotubes ◽  
Molecular Magnets ◽  
Multiwalled Carbon ◽  
Blood Capillaries ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Human adipose-derived stem cells (hASCs) are an attractive cell source for therapeutic applicability in diverse fields for the repair and regeneration of damaged or malfunctioning tissues and organs. There is a growing number of cell therapies using stem cells due to their characteristics of modulation of immune system and reduction of acute rejection. So a challenge in stem cells therapy is the delivery of cells to the organ of interest, a specific site. The aim of this paper was to investigate the effects of a supramolecular assembly composed of single-walled carbon nanotubes (SWCNT), molecular magnets (lawsone-Co-phenanthroline), and a synthetic peptide (FWYANHYWFHNAFWYANHYWFHNA) in the hASCs cultures. The hASCs were isolated, characterized, expanded, and cultured with the SWCNT supramolecular assembly (SWCNT-MA). The assembly developed did not impair the cell characteristics, viability, or proliferation. During growth, the cells were strongly attached to the assembly and they could be dragged by an applied magnetic field of less than 0.3 T. These assemblies were narrower than their related allotropic forms, that is, multiwalled carbon nanotubes, and they could therefore be used to guide cells through thin blood capillaries within the human body. This strategy seems to be useful as noninvasive and nontoxic stem cells delivery/guidance and tracking during cell therapy.

scholarly journals Noncovalent Attachment of PbS Quantum Dots to Single- and Multiwalled Carbon Nanotubes

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Anirban Das ◽  
Eric Hall ◽  
Chien M. Wai
Keyword(s):  
Carbon Nanotubes ◽  
Quantum Dots ◽  
Oleic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Single Walled Carbon Nanotubes ◽  
Stacking Interactions ◽  
Multiwalled Carbon ◽  
Nir Fluorescence ◽  
Walled Carbon Nanotubes ◽  
Pbs Quantum Dots

Attachment of PbS quantum dots (QD) to single-walled carbon nanotubes (SWNT) and multiwalled carbon nanotubes (MWCNT) is described; wherein commercially obtained PbS-QD of size 2.7 nm, stabilized by oleic acid, are added to a suspension of single- or multiwalled carbon nanotubes (CNT) prefunctionalized noncovalently with 1,2-benzenedimethanethiol (1,2-BDMT) in ethanol. The aromatic part of 1,2-BDMT attaches to the CNT byπ-πstacking interactions, noncovalently functionalizing the CNT. The thiol part of the 1,2-BDMT on the functionalized CNT replaces oleic acid on the surface of the QD facilitating the noncovalent attachment of the QD to the CNT. The composites were characterized by TEM and FTIR spectroscopy. Quenching of NIR fluorescence of the PbS-QD on attachment to the carbon nanotubes (CNT) was observed, indicating FRET from the QD to the CNT.

Characterization of Mechanical and Viscoelastic Properties of SC-15 Epoxy Nanocomposites Reinforced With Multi-Walled Carbon Nanotubes, Nanoclay and Binary Nanoparticles

2014 ◽  
Author(s):  
Tanjheel H. Mahdi ◽  
Mohammad E. Islam ◽  
Mahesh V. Hosur ◽  
Alfred Tcherbi-Narteh ◽  
S. Jeelani
Keyword(s):  
Carbon Nanotubes ◽  
Epoxy Resin ◽  
Viscoelastic Properties ◽  
Flexural Modulus ◽  
Epoxy Nanocomposites ◽  
Multiwalled Carbon ◽  
Epoxy Resin System ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Binary Nanoparticles

Mechanical and viscoelastic properties of polymer nanocomposites reinforced with carboxyl functionalized multiwalled carbon nanotubes (COOH-MWCNT), montmorillonite nanoclays (MMT) and MWCNT/MMT binary nanoparticle were investigated. In this study, 0.3 wt. % of COOH-MWCNT, 2 wt. % of MMT and 0.1 wt. % COOH-MWCNT/2 wt. % MMT binary nanoparticles by weight of epoxy were incorporated to modify SC-15 epoxy resin system. The nanocomposites were subjected to flexure test, dynamic mechanical and thermomechanical analyses. Morphological study was conducted with scanning electron microscope. Addition of each of the nanoparticles in epoxy showed significant improvement in mechanical and viscoelastic properties compared to those of control ones. But, best results were obtained for addition of 0.1% MWCNT/2% MMT binary nanoparticles in epoxy. Nanocomposites modified with binary nanoparticles exhibited about 20% increase in storage modulus as well as 25° C increase in glass transition temperature. Flexural modulus for binary nanoparticle modified composites depicted about 30% improvement compared to control ones. Thus, improvement of mechanical and viscoelastic properties was achieved by incorporating binary nanoparticles to epoxy nanocomposites. The increase in properties was attributed to synergistic effect of MWCNTs and nanoclay in chemically interacting with each other and epoxy resin as well as in arresting and delaying the crack growth once initiated.

scholarly journals Effect of Increasing the Strength of Aluminum Matrix Nanocomposites Reinforced with Microadditions of Multiwalled Carbon Nanotubes Coated with TiC Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1596 ◽  
Author(s):  
Artemiy Aborkin ◽  
Kirill Khorkov ◽  
Evgeny Prusov ◽  
Anatoly Ob’edkov ◽  
Kirill Kremlev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Aluminum Matrix ◽  
High Energy ◽  
High Tech ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
Tic Nanoparticles ◽  
Matrix Nanocomposites

Aluminum matrix composites reinforced with multiwalled carbon nanotubes (MWCNTs) are promising materials for applications in various high-tech industries. Control over the processes of interfacial interaction in Al/MWCNT composites is important to achieve a high level of mechanical properties. The present study describes the effects of coating MWCNTs with titanium carbide nanoparticles on the formation of mechanical properties and the evolution of the reinforcement structure in bulk aluminum matrix nanocomposites with low concentrations of MWCNTs under conditions of solid-phase consolidation of ball-milled powder mixtures. Using high-energy ball milling and uniaxial hot pressing, two types of bulk nanocomposites based on aluminum alloy AA5049 that were reinforced with microadditions of MWCNTs and MWCNTs coated with TiC nanoparticles were successfully produced. The microstructural and mechanical properties of the Al/MWCNT composites were investigated. The results showed that, on the one hand, the TiC nanoparticles on the surface of the MWCNT hybrid reinforcement reduced the damage of reinforcement under the intense exposure of milling bodies, and on the other hand, they reduced the contact area of the MWCNTs with the matrix material (acting as a barrier interface), which also locally inhibited the reaction between the matrix and the MWCNTs.

scholarly journals Study of the Nanocomposite cBN/TiC-SWCNTs by Field Actived Sparck Plasma Sintering Process

2020 ◽  
Vol 1 (2) ◽  
pp. 14-29
Author(s):  
Badis Bendjemil ◽  
Badis Bendjemil ◽  
Mohamed Mouyane ◽  
Jacques G. Noudem ◽  
Jérôme Bernard ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Protective Layers ◽  
Plasma Sintering ◽  
The Matrix ◽  
Ceramics Matrix ◽  
Walled Carbon Nanotubes ◽  
Matrix Nanocomposites

Cubic boron nitrid (cBN) bonded TiC and alloyed with single walled carbon nanotubes (SWCNTs or NC) ceramics matrix nanocomposites (CMNCs) tools were manufacturated by a field actived sparck plasma sintering processus (FASPS). The effects of cBN-TiC ratio, carbon nanotubes and optimisation of the sintering process on the microstructure, densification in addition mechanical and vibronic properties of NC-cBN-TiC nanocomposites were studied. The results showed that for the nanocomposite cBN-TiC vol. ratio of 8:2 with 0.1 wt% NC, it was found that microhardness incresses significantly with addition of carbon nanotubes exhibited the highest microhardness and fracture toughness. After sintering of the samples at 1800 °C, 10 mn, 75 MPa of cBN–TiC1-x, x=0.8 with and without addition of 0.1 wt% NC were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction. The samples exhibited a dense polycrystalline structure. From the resonant Raman scattering we can locate the vibration frequency of the transformation cBN to hexagonal boron nitrid (hBN) and formation of secondary hard phase TiB2to consolid the (CMNCs) tools. The final product is hBN-TiC-TiB2-NC.The best product contained cBNx-TiC1-x (x=0.8)-0.1 wt % NC which was sintered at 1800 °C, 75 MPa for 10 mn. The Vickers hardness of cBN-TiC1-x (x=0.8) incresses with NC incorporation in the matrix The indentation fracture toughness was calculated to be 12.30 MPa m1/2 for cBNx-TiC1-x (x=0.8 -0.1 wt % NC ceramics matrix nanocomposite (CMNCs) tools with excellent wear resistant will be confirmed. The wear of cBN-TiC of the composites tools have shown that this is predominantly a chemical process involving the interaction of the tool with its environment and is restricted by the formation of protective layers on the exposed faces of the tool by the addition of carbon nanotubes (NC). The wear features of tools used in fine cutting tests under identical conditions will be compared and the results will be interpreted in terms of the existing models for the wear of cBN -based nanomaterials by the effects of the additives in the modified tools

Investigation of fracture toughness parameters of epoxy nanocomposites for different crack angles

2012 ◽  
Vol 32 (4-5) ◽  
pp. 311-317
Author(s):  
Abdolhossein Fereidoon ◽  
Lia Mottahedin ◽  
Sara Tahan Latibari
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Single Walled Carbon Nanotubes ◽  
Tensile Loading ◽  
3D Finite Element ◽  
Scaling Properties ◽  
Pure Epoxy ◽  
Walled Carbon Nanotubes ◽  
Epoxy Systems

Abstract The effects of single-walled carbon nanotubes (SWCNTs) on the mechanical properties of nanocomposites with epoxy matrix were studied, with the emphasis on fracture toughness under tensile loading conditions. It has been demonstrated that adding CNTs into polymer-based materials can improve the mechanical properties of this material. CNTs possess a certain potential to improve the fracture toughness of epoxy systems due to their mechanical properties and increase the fracture toughness of nanocomposites. Since the fracture toughness parameters were best manifested in the scaling properties and were the main parameters, the angles of different cracks have been simulated in a 3D finite element framework and the effects of different angles of crack, on the fracture toughness of polymers, have been modeled and investigated. The simulations are run for different bias angles. The influence of angle, the crack lengths and the variations of different lengths of nanocomposite in different volume fractions (vol%) are investigated. That is to say, at first, nanocomposites had a significantly higher fracture toughness compared to the pure epoxy. We found that nanocomposites, in the presence of SWCNTs, had a greater effect on fracture toughness of nanocomposites in a greater volume of fractions. Also, the nanocomposites exhibited a significant increase in fracture toughness, with zero angle of crack compared with greater angles. In addition, it is found that at a constant volume fracture, fracture toughness, increases by increasing crack lengths.

scholarly journals Thermal Conductivity of Epoxy Resin Reinforced with Magnesium Oxide Coated Multiwalled Carbon Nanotubes

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Fei-Peng Du ◽  
Hao Tang ◽  
De-Yong Huang
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Magnesium Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Epoxy Matrix ◽  
Content Increase ◽  
Epoxy Nanocomposites ◽  
Multiwalled Carbon ◽  
Mwnt Content ◽  
Filler Content Increase

Magnesium oxide coated multiwalled carbon nanotubes (MgO@MWNT) were fabricated and dispersed into epoxy matrix. The microstructures of MgO@MWNT and epoxy/MgO@MWNT nanocomposites were characterized by TEM and SEM. Electrical resistivity and thermal conductivity of epoxy nanocomposites were investigated with high resistance meter and thermal conductivity meter, respectively. MgO@MWNT has core-shell structure with MgO as shell and nanotube as core, and the thickness of MgO shell is ca. 15 nm. MgO@MWNT has been dispersed well in the epoxy matrix. MgO@MWNT loaded epoxy nanocomposites still retain electrical insulation inspite of the filler content increase. However, thermal conductivity of epoxy was increased with the MgO@MWNT content increasing. When MgO@MWNT content reached 2.0 wt.%, thermal conductivity was increased by 89% compared to neat epoxy, higher than that of unmodified MWNT nanocomposites with the same loading content.

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