Development and application of a digestion-Raman analysis approach for studying multiwall carbon nanotube uptake in lettuce

2018 ◽  
Vol 5 (3) ◽  
pp. 659-668 ◽  
Author(s):  
Kamol K. Das ◽  
Yaqi You ◽  
Miguel Torres ◽  
Felipe Barrios-Masias ◽  
Xilong Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Nitric Acid ◽  
Multiwall Carbon Nanotubes ◽  
Analysis Approach ◽  
Multiwall Carbon Nanotube ◽  
Raman Analysis ◽  
Multiwall Carbon

Optimized plant digestion using nitric acid in conjunction with Raman analysis is an effective approach for detecting and analyzing multiwall carbon nanotubes in lettuce plants.

Thermal conductivity and flammability of multiwall carbon nanotube/polyurethane foam composites

2016 ◽  
Vol 53 (2) ◽  
pp. 215-230 ◽  
Author(s):  
JJ Espadas-Escalante ◽  
F Avilés ◽  
PI Gonzalez-Chi ◽  
AI Oliva
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Polyurethane Foam ◽  
Fire Behavior ◽  
Multiwall Carbon Nanotubes ◽  
Propagation Speed ◽  
Interfacial Thermal Resistance ◽  
Multiwall Carbon Nanotube ◽  
Multiwall Carbon

The thermal conductivity and fire response of multiwall carbon nanotube/polyurethane foam composites are investigated for ∼45 kg/m3 foams with multiwall carbon nanotube concentrations of 0.1, 1, and 2 wt.%. The thermal conductivity of such nanocomposites shows a modest increase with increased multiwall carbon nanotube content, which is explained by a high value of interfacial thermal resistance, as predicted by existent thermal models. A strong correlation between multiwall carbon nanotube content, foam’s cellular morphology, and fire behavior was observed. The flame propagation speed increases with the addition of 0.1 wt.% multiwall carbon nanotubes and then reduces as the multiwall carbon nanotube content increases. The mass lost after flame extinction reduces with the addition of multiwall carbon nanotubes, suggesting an increased resistance to flame attack due the multiwall carbon nanotube presence.

Development of Rubber Nanocomposites for Engineering Application

2016 ◽  
Vol 852 ◽  
pp. 61-65
Author(s):  
Paulraj Jawahar ◽  
Parthasarathy Kartheeswaran
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Natural Rubber ◽  
Engineering Application ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon Nanotube ◽  
Wide Range ◽  
Rubber Nanocomposites ◽  
Multiwall Carbon

Rubber finds wide range of application in automotive sector starting from tires to rubber bushes. Incorporation of nanoparticles like carbon nanotubes to rubber has improved the mechanical properties significantly. Still dispersion of carbon nanotube in raw rubber is a challenging process. In this work multiwall carbon nanotubes (MWCNT) are dispersed in the varying proportions (0.5, 1, 1.5 wt.%) in high viscous aromatic rubber processing oil using high shear planetary ball mill for a period of 2 hours. Then the rubber nanocomposites have been processed in double roll mill by adding the chemicals in the following order (Natural Rubber, Antioxidant: 1 phr, Oil: 5 phr, Zinc Oxide: 4 phr, Stearic Acid: 2 phr, Accelerator: 1 phr, Sulfur: 2 phr). It was found that, the incorporation of Multiwall carbon nanotube (MWCNT) has improved the mechanical properties of natural rubber significantly. Din abrasion studies show improvement in wear resistance of natural rubber incorporated with multiwall carbon nanotube.

Electrical self-sensing of strain and damage of thermoplastic hierarchical composites subjected to monotonic and cyclic tensile loading

2019 ◽  
Vol 30 (10) ◽  
pp. 1527-1537 ◽  
Author(s):  
O Rodríguez-Uicab ◽  
C Martin-Barrera ◽  
A May-Pat ◽  
A Can-Ortiz ◽  
PI Gonzalez-Chi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Electrical Response ◽  
Multiwall Carbon Nanotubes ◽  
Tensile Loading ◽  
Multiwall Carbon Nanotube ◽  
Aramid Fibers ◽  
Hierarchical Composites ◽  
Polypropylene Matrix ◽  
Multiwall Carbon

Electrical monitoring of strain and damage in multiscale hierarchical composites comprising unidirectional aramid fibers modified by multiwall carbon nanotubes and polypropylene as matrix is investigated. The key factor for electrical self-sensing in these thermoplastic composites is the formation of a multiwall carbon nanotube network, which is achieved by using two material architectures. In the first architecture, the multiwall carbon nanotubes are dispersed within the polypropylene matrix, while aramid fibers remain unmodified. The second architecture uses also multiwall carbon nanotube-modified polypropylene matrix, but the aramid fibers are also modified by depositing multiwall carbon nanotubes. Under tensile loading, the electrical response is nonlinear with strain ( ε), and the piezoresistive sensitivity was quantified by gage factors corresponding to low ( ε < 0.25%) and high ( ε > 0.3%) strain regimes. Such gage factors were 4.83 (for ε < 0.25%) and 13.2 (for ε > 0.3%) for composites containing multiwall carbon nanotubes only in the polypropylene matrix. The composites containing multiwall carbon nanotubes in the matrix and fibers presented higher piezoresistive sensitivity, with average gage factors of 9.24 ( ε < 0.25%) and 14.0 ( ε > 0.3%). The higher sensitivity to strain and damage for a specific material architecture was also evident during cyclic and constant strain loading programs and is attributed to the preferential localization of multiwall carbon nanotubes in the hierarchical composite.

Energetic Ion Bombardment of Carbon Nanotubes

2015 ◽  
Vol 1743 ◽  
Author(s):  
Gregory A. Konesky
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Multiwall Carbon Nanotubes ◽  
High Strength ◽  
Ion Bombardment ◽  
Multiwall Carbon Nanotube ◽  
Self Healing ◽  
Energetic Ions ◽  
Multiwall Carbon

ABSTRACTCarbon Nanotubes (CNTs) exhibit exceptional properties in terms of high strength-to-weight, high electrical conductivity, and high thermal conductivity, and have been employed as a reinforcement in various composites and other materials. Their tolerance to radiation environments may be suggested by their response to energetic ion bombardment. We discuss the effects of argon ion bombardment of both thin and thick multiwall carbon nanotube films over a range of 4 to 11 keV at fluence levels up to the order of 1021 ions/cm2. While individual carbon atoms are readily displaced from a carbon nanotube by bombardment at these energies, these nanotubes also exhibit a self-healing capability. At moderate energies and fluence, if two or more carbon nanotubes are touching and an ion strikes this point, they heal together where a junction or cross-link between them is created and the nanotubes interpenetrate. Even though some of the properties of the carbon nanotubes may be degraded by ion bombardment at non-junction regions, we have demonstrated a bulk cross-linked thin film of randomly oriented multiwall carbon nanotubes with an isotropic thermal conductivity of 2150 W/m K. At higher energies and fluence, the carbon nanotubes appear to collapse and reform aligned parallel to the incoming ion bombardment trajectory, producing high aspect ratio tapered structures. These structures are, in general, fully dense, unlike the loosely packed random carbon nanotube array from which they originated. There is also a sharp transition at the base of these structures from the dense form to the loose-packed form, suggesting that these structures may inhibit further penetration of the energetic ions.

scholarly journals Dispersion of Multiwall Carbon Nanotubes in Organic Solvents through Hydrothermal Supercritical Condition

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Krishnegowda Jagadish ◽  
Shivanna Srikantaswamy ◽  
Kullaiah Byrappa ◽  
Lingaraju Shruthi ◽  
Mavinakere Ramesh Abhilash
Keyword(s):  
Carbon Nanotubes ◽  
Particle Size ◽  
Carbon Nanotube ◽  
Organic Solvents ◽  
Isopropyl Alcohol ◽  
Hydrothermal Reaction ◽  
Multiwall Carbon Nanotubes ◽  
Binding Energies ◽  
Multiwall Carbon Nanotube ◽  
Multiwall Carbon

Multiwall carbon nanotube (MWCNT) composite materials require careful formulation of processing methods to ultimately realize the desired properties. Until now, controlled dispersion of MWCNT remains a challenge, due to strong van der Waals binding energies associated with the MWCNT aggregates. In the present study, an effort has been made to disperse MWCNTs in organic solvents like dichloromethane, ethanol, isopropyl alcohol, and hexane through hydrothermal reaction. Dichloromethane is considered the best solvent for the dispersion of MWCNTs. The characterizations were carried out to find the dispersion design, particle size, and stabilization, which clearly indicate that the desired properties of MWCNTs have been achieved.

scholarly journals Fabrication And Properties Of Silver Based Multiwall Carbon Nanotube Composite Prepared By Spark Plasma Sintering Method

2015 ◽  
Vol 60 (2) ◽  
pp. 1351-1355 ◽  
Author(s):  
M. Lis ◽  
A. Wrona ◽  
J. Mazur ◽  
C. Dupont ◽  
M. Kamińska ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Spark Plasma Sintering ◽  
Chemical Reduction ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon Nanotube ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method ◽  
Multiwall Carbon

Abstract The paper presents results of investigations of the obtained nanocomposite materials based on silver with addition of multiwall carbon nanotubes. The powder of carbon nanotubes content from 0.1 to 3 wt. % was produced by application of powder metallurgy methods, through mixing and high-energetic milling, and also chemical methods. Modification of carbon nanotubes included electroless deposition of silver particles on the carbon nanotube active surfaces and chemical reduction with strong reducing agent – sodium borohydride (NaBH4). The obtained powder mixtures were consolidated by SPS – Spark Plasma Sintering method. The formed composites were subjected to tests of relative density, electrical conductivity and electro-erosion properties. Detailed examinations of the structure with application of X-ray microanalysis, with consideration of carbon nanotubes distribution, were also carried out. The effect of manufacturing methods on properties of the obtained composites was observed.

Sign in / Sign up

Export Citation Format

Share Document