iPP/CNTs Multifunctional Polymer Nanocomposite

2012 ◽  
Vol 1403 ◽  
Author(s):  
Parvathalu Kalakonda ◽  
Sabyasachi Sarkar ◽  
Erin A. Gombos ◽  
Georgi Yordanov Georgiev ◽  
Germano Iannacchione ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Mechanical Stability ◽  
Orientational Order ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Properties ◽  
Polymer Nanocomposite ◽  
Hybrid Structure ◽  
Index Of Refraction ◽  
Induced Anisotropy

ABSTRACTWe present a hybrid structure of Isotactic Polypropylene (iPP) nanocomposite with multiwall carbon nanotubes (MWCNTs). The polymer component contributes to the optical properties, flexibility and integrity of the polymer film while the carbon nanotubes change the thermal and mechanical stability, electrical and thermal conductivity and sensitivity. The multifunctional characteristics of this nanocomposite material are enhanced by anisotropic organization of the nanotubes and polymer through melt shearing which provides organization of the structural constituents at the molecular, nano, and micro length scales. This results in anisotropy of the macroscopic composite film properties parallel and perpendicular to the direction of shearing. On the molecular scale, the CNTs control the arrangement of the polymer molecules in a crystal lattice. On the nanometer scale, the CNTs couple to and align with the smectic normal of the liquid crystal phase of iPP. On the micron scale and larger, the secondary polymer crystal structure is rearranged due to the pinning of the polymer at the CNT surface to form fibrillar rather than spherulitic structures. These multi-scale rearrangements affect the optical, thermal, electrical, mechanical and chemical properties of the nanocomposite film. Our findings indicate that the CNTs under shear induce a novel anisotropy to the various thermo-physical properties of the iPP/CNTs films. We introduce an approach to extract the shear induced orientational order from the thermal conductivity of the dispersed CNTs. The index of refraction of the nanocomposites was also estimated via ellipsometry and was found to decrease slightly when CNTs were added and also showed shear induced anisotropy. The comparison between the results from the different experiments methods for probing induced anisotropy by melt shearing shows that orientation in iPP/CNTs nanocomposites induces anisotropy in multiple macroscopic properties.

A closed-form model for estimating the effective thermal conductivities of carbon nanotube–polymer nanocomposites

2018 ◽  
Vol 233 (8) ◽  
pp. 2909-2919 ◽  
Author(s):  
Reza Moheimani ◽  
M Hasansade
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Closed Form ◽  
Polymer Nanocomposites ◽  
Micromechanical Model ◽  
Polymer Nanocomposite ◽  
Interfacial Thermal Resistance ◽  
Full Potential ◽  
Thermal Conductivities

This paper describes a closed-form unit cell micromechanical model for estimating the effective thermal conductivities of unidirectional carbon nanotube reinforced polymer nanocomposites. The model incorporates the typically observed misalignment and curvature of carbon nanotubes into the polymer nanocomposites. Also, the interfacial thermal resistance between the carbon nanotube and the polymer matrix is considered in the nanocomposite simulation. The micromechanics model is seen to produce reasonable agreement with available experimental data for the effective thermal conductivities of polymer nanocomposites reinforced with different carbon nanotube volume fractions. The results indicate that the thermal conductivities are strongly dependent on the waviness wherein, even a slight change in the carbon nanotube curvature can induce a prominent change in the polymer nanocomposite thermal conducting behavior. In general, the carbon nanotube curvature improves the nanocomposite thermal conductivity in the transverse direction. However, using the straight carbon nanotubes leads to maximum levels of axial thermal conductivities. With the increase in carbon nanotube diameter, an enhancement in nanocomposite transverse thermal conductivity is observed. Also, the results of micromechanical simulation show that it is necessary to form a perfectly bonded interface if the full potential of carbon nanotube reinforcement is to be realized.

Anisotropic thermal conductivity of polypropylene composites filled with carbon fibers and multiwall carbon nanotubes

2014 ◽  
Vol 36 (11) ◽  
pp. 1951-1957 ◽  
Author(s):  
Ilya Mazov ◽  
Igor Burmistrov ◽  
Igor Il'inykh ◽  
Andrey Stepashkin ◽  
Denis Kuznetsov ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Fibers ◽  
Multiwall Carbon Nanotubes ◽  
Polypropylene Composites ◽  
Anisotropic Thermal Conductivity ◽  
Multiwall Carbon

scholarly journals Effect of Carboxylic Functional Group Functionalized on Carbon Nanotubes Surface on the Removal of Lead from Water

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Muataz Ali Atieh ◽  
Omer Yehya Bakather ◽  
Bassam Al-Tawbini ◽  
Alaadin A. Bukhari ◽  
Faraj Ahmad Abuilaiwi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Functional Group ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Properties ◽  
Average Diameter ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
Multiwall Carbon ◽  
Carboxylic Functional Group

The adsorption mechanism of the removal of lead from water by using carboxylic functional group (COOH) functionalized on the surface of carbon nanotubes was investigated. Four independent variables including pH, CNTs dosage, contact time, and agitation speed were carried out to determine the influence of these parameters on the adsorption capacity of the lead from water. The morphology of the synthesized multiwall carbon nanotubes (MWCNTs) was characterized by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) in order to measure the diameter and the length of the CNTs. The diameters of the carbon nanotubes were varied from 20 to 40 nm with average diameter at 24 nm and 10 micrometer in length. Results of the study showed that 100% of lead was removed by using COOH-MCNTs at pH 7, 150 rpm, and 2 hours. These high removal efficiencies were likely attributed to the strong affinity of lead to the physical and chemical properties of the CNTs. The adsorption isotherms plots were well fitted with experimental data.

Thermal conductivity of polypropylene-based composites with multiwall carbon nanotubes with different diameter and morphology

2014 ◽  
Vol 586 ◽  
pp. S440-S442 ◽  
Author(s):  
I.N. Mazov ◽  
I.A. Ilinykh ◽  
V.L. Kuznetsov ◽  
A.A. Stepashkin ◽  
K.S. Ergin ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon

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.

scholarly journals Not Without Engineering

2001 ◽  
Vol 123 (02) ◽  
pp. 46-49 ◽  
Author(s):  
Arun Majumdar
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Room Temperature ◽  
Microelectromechanical Systems ◽  
Multiwall Carbon Nanotubes ◽  
University Of California ◽  
High Mechanical Strength ◽  
Optical Signals ◽  
The University ◽  
Multiwall Carbon

Recent experiments have shown that thermal conductivity of carbon nanotubes can be more than twice that of diamond. It should be noted that high mechanical strength often comes with high thermal conductivities. Recent experiments have shown that the thermal conductivity of carbon nanotubes can be as high as 3000 to 6000 W/m K at room temperature, which is more than twice that of diamond. It was recently shown by Alex Zettl and his group at the University of California, Berkeley that the relative motion between different shells of multiwall carbon nanotubes has some unique properties and can serve as excellent mechanical bearings that do not undergo any wear. Recent work has led to multifunctional probes, which, besides topography, can detect thermal, electrical, magnetic, and optical signals at nanoscales. The engineering challenge now is to develop microelectromechanical systems (MEMS)-based probes that integrate multiple functions on a single tip.

Influence of multiwalled carbon nanotubes content on thermal conductivity of polyactic acid/liquid natural rubber nanocomposite

2016 ◽  
Vol 13 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Mou’ad A. Tarawneh ◽  
Adilah Mat Ali ◽  
Sahrim Hj Ahmad ◽  
L.J. Yu
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Natural Rubber ◽  
Polymer Nanocomposite ◽  
Multiwalled Carbon ◽  
Content Type ◽  
Blending Method ◽  
Liquid Natural Rubber ◽  
Sem Micrograph ◽  
Multi Walled Carbon Nanotubes

Purpose The purpose of this paper is to study the effects of multi-walled carbon nanotubes (MWCNTs) loading on the thermal conductivity of nanocomposites. Design/methodology/approach In this paper, the polymer nanocomposite of MWCNT nanoparticles incorporated with PLA and LNR as compatibilizer were prepared via melt blending method. Findings The result has shown that the sample with 3.5 wt.% of MWCNT content provided higher thermal conductivity which is believed to be the optimum loading that formed the suitable percolated network for phonon conduction facilitation because of better dispersion in the PLA/LNR matrix as confirmed by SEM micrograph. Originality/value Thermal conductivity of polylactic acid (PLA)/liquid natural rubber (LNR) matrix improved with MWCNT.

Optical Transport Properties of Oriented Isotactic Polypropylene and Carbon Nanotube Nanocomposite Thin Films

2012 ◽  
Vol 1410 ◽  
Author(s):  
Sabyasachi Sarkar ◽  
Parvathalu Kalakonda ◽  
Georgi Y. Georgiev ◽  
Germano S. Iannacchione ◽  
Peggy Cebe
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Isotactic Polypropylene ◽  
Optical Transmission ◽  
Multiwall Carbon Nanotubes ◽  
Index Of Refraction ◽  
Nanocomposite Films ◽  
Nanocomposite Thin Films ◽  
Optical Transport ◽  
Multiwall Carbon

ABSTRACTOptical transport through Isotactic Polypropylene (iPP) and multiwall carbon nanotubes (MWCNTs) nanocomposite thin films is important to many applications where optical transmission or polarization are used. Especially interesting is the case where the optical properties are anisotropic as in oriented thin films and the optical transport is different in the direction of orientation and perpendicular to it. Changing the orientation of the film or the polarization of the light can change the way in which the nanocomposite film interacts with light. Our polymer of choice, Isotactic Polypropylene, is one of the most widely used polymers which will increase the applicability of our results. We blended iPP with different concentration of carbon nanotubes (CNTs): 1%, 2% and 5% and oriented the thin film samples using melt-shear at 200°C and 1Hz in a Linkam microscope sharing hot stage. We measured that the index of refraction of the nanocomposites slightly decreased when CNTs are added and that when nanocomposites were shear-oriented at low loading of CNTs the index of refraction showed small difference in directions parallel and perpendicular to the direction of orientation. The extinction coefficient increased therefore it’s tuning in the nanocomposite films by the content of the carbon nanotubes can help devise new materials with the desired values of this property.

Microwave Absorbing Nanocomposites Composed with and without Polyaniline by Use as Radar Absorbing Structure

2012 ◽  
Vol 730-732 ◽  
pp. 920-924 ◽  
Author(s):  
Luiza de Castro Folgueras ◽  
Mirabel Cerqueira Rezende
Keyword(s):  
Carbon Nanotubes ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Properties ◽  
Woven Fabric ◽  
Electromagnetic Properties ◽  
Naval Research ◽  
Radar Absorbing Structure ◽  
Physical And Chemical ◽  
Multiwall Carbon ◽  
And Chemical Properties

In the past decade, new materials have been developed based on the physical and chemical properties of carbon nanotubes. The combination of polyaniline with multiwall carbon nanotubes results in a new functional material with advantageous electromagnetic properties. The objective of this study was to produce a radar absorbing structure consisting of glass fiber woven fabric impregnated with a formulation containing carbon nanotubes, polyurethane resin, with or without polyaniline. A different formulation was used for each woven sheet (multilayer structure). The electromagnetic properties of these nanocomposite materials were characterized by reflectivity measurements using Naval Research Laboratory arch method (frequency range, 8 to 12 GHz). The attenuation of both sides of each nanocomposite material was also measured and compared. The attenuation of electromagnetic energy was as high as 70 %, approximately, indicating that these materials can be used as microwave absorbers.

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