Mechanism and the Effect of Microwave-Carbon Nanotube Interaction

Mechanism and the Effect of Microwave-Carbon Nanotube Interaction

Date: December 2005
Creator: Ye, Zhou
Description: A series of experimental results about unusual heating of carbon nanotubes by microwaves is analyzed in this dissertation. Two of vibration types, cantilever type (one end is fixed and the other one end is free), the second type is both ends are fixed, have been studied by other people. A third type of forced vibration of carbon nanotubes under an alternating electromagnetic field is examined in this paper. Heating of carbon nanotubes (CNTs) by microwaves is described in terms of nonlinear dynamics of a vibrating nanotube. Results from the model provide a way to understand several observations that have been made. It is shown that transverse vibrations of CNTs during microwave irradiation can be attributed to transverse parametric resonance, as occurs in the analysis of Melde's experiment on forced longitudinal vibrations of a stretched elastic string. For many kinds of carbon nanotubes (SWNT, DWNT, MWNT, ropes and strands) the resonant parameters are found to be located in an unstable region of the parameter space of Mathieu's equation. Third order wave equations are used to qualitatively describe the effects of phonon-phonon interactions and energy transfer from microwaves to CNTs. This result provides another way to input energy from microwaves to carbon ...
Contributing Partner: UNT Libraries
Charge interaction effects in epoxy with cation exchanged montmorillonite clay and carbon nanotubes.

Charge interaction effects in epoxy with cation exchanged montmorillonite clay and carbon nanotubes.

Date: May 2005
Creator: Butzloff, Peter Robert
Description: The influence of charge heterogeneity in nanoparticles such as montmorillonite layered silicates (MLS) and hybrid systems of MLS + carbon nanotubes was investigated in cured and uncured epoxy. Epoxy nanocomposites made with cation-exchanged montmorillonite clay were found to form agglomerates near a critical concentration. Using differential scanning calorimetry it was determined that the mixing temperature of the epoxy + MLS mixture prior to the addition of the curing agent critically influenced the formation of the agglomerate. Cured epoxy samples showed evidence of the agglomerate being residual charge driven by maxima and minima in the concentration profiles of thermal conductivity and dielectric permittivity respectively. A hybrid nanocomposite of MLS and aniline functionalized multi walled nanotubes indicated no agglomerates. The influence of environmentally and process driven properties on the nanocomposites was investigated by examination of moisture, ultrasound, microwaves and mechanical fatigue on the properties of the hybrid systems. The results point to the importance of charge screening by adsorbed or reacted water and on nanoparticulates.
Contributing Partner: UNT Libraries
A magnetorheological study of single-walled and multi-walled carbon nanotube dispersions in mineral oil and epoxy resin.

A magnetorheological study of single-walled and multi-walled carbon nanotube dispersions in mineral oil and epoxy resin.

Date: May 2005
Creator: Yang, Zhengtao
Description: Single wall carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) were dispersed in mineral oil and epoxy resin. The magnetorheological properties of these dispersions were studied using a parallel plate rheometer. Strain sweeps, frequency sweeps, magneto sweeps and steady shear tests were conducted in various magnetic fields. G', G", h* and ty increased with increasing magnetic field, which was partially attributed to the increasing degree of the alignment of nanotubes in a stronger magnetic field. The SWNT/mo dispersions exhibited more pronounced magnetic field dependence than SWNT/ep and MWNT/mo counterparts due to their much lower viscosity. The alignment of SWNTs in mineral oil increased with rising nanotube concentration up to 2.5vol% but were significantly restricted at 6.41vol% due to nanotube flocculation.
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High-Precision Micropipette Thermal Sensor for Measurement of Thermal Conductivity of Carbon Nanotubes Thin Film

High-Precision Micropipette Thermal Sensor for Measurement of Thermal Conductivity of Carbon Nanotubes Thin Film

Date: August 2011
Creator: Shrestha, Ramesh
Description: The thesis describes novel glass micropipette thermal sensor fabricated in cost-effective manner and thermal conductivity measurement of carbon nanotubes (CNT) thin film using the developed sensor. Various micrometer-sized sensors, which range from 2 µm to 30 µm, were produced and tested. The capability of the sensor in measuring thermal fluctuation at micro level with an estimated resolution of ±0.002oC is demonstrated. The sensitivity of sensors was recorded from 3.34 to 8.86 µV/oC, which is independent of tip size and dependent on the coating of Nickel. The detailed experimental setup for thermal conductivity measurement of CNT film is discussed and 73.418 W/moC was determined as the thermal conductivity of the CNT film at room temperature.
Contributing Partner: UNT Libraries
Lip-Lip Interactions and the Growth of Multiwalled Carbon Nanotubes

Lip-Lip Interactions and the Growth of Multiwalled Carbon Nanotubes

Date: January 12, 1998
Creator: Buongiorno Nardelli, Marco; Brabec, Charles; Roland, Christopher & Bernholc, Jerry
Description: Article on lip-lip interactions and the growth of multiwalled carbon nanotubes.
Contributing Partner: UNT College of Arts and Sciences
Mechanical deformations and coherent transport in carbon nanotubes

Mechanical deformations and coherent transport in carbon nanotubes

Date: December 15, 1999
Creator: Buongiorno Nardelli, Marco & Bernholc, Jerry
Description: Article on mechanical deformations and coherent transport in carbon nanotubes.
Contributing Partner: UNT College of Arts and Sciences
Mechanism of strain release in carbon nanotubes

Mechanism of strain release in carbon nanotubes

Date: February 15, 1998
Creator: Buongiorno Nardelli, Marco; Yakobson, Boris I. & Bernholc, Jerry
Description: Article on the mechanism of strain release in carbon nanotubes.
Contributing Partner: UNT College of Arts and Sciences
Effects of O2, Ar, and H2 gases on the field-emission properties of single-walled and multiwalled carbon nanotubes

Effects of O2, Ar, and H2 gases on the field-emission properties of single-walled and multiwalled carbon nanotubes

Date: September 17, 2001
Creator: Wadhawan, Atul; Stallcup, Richard E.; Stephens, Kenneth F.; Pérez, José M. & Akwani, Ikerionwu A.
Description: In this article, the authors compare the effects of O2, Ar, and H2 gases on the field-emission (FE) properties of single-walled carbon nanotubes (SWNTs) and multiwalled carbon nanotubes (MWNTs).
Contributing Partner: UNT College of Arts and Sciences
Ion Beam Analyses of Carbon Nanotubes

Ion Beam Analyses of Carbon Nanotubes

Date: January 7, 2005
Creator: Naab, Fabian U.; Holland, Orin W.; Duggan, Jerome L. & McDaniel, Floyd Del. (Floyd Delbert), 1942-
Description: This article discusses ion beam analyses of carbon nanotubes.
Contributing Partner: UNT College of Arts and Sciences
Ab initio transport properties of nanostructures from maximally localized Wannier functions

Ab initio transport properties of nanostructures from maximally localized Wannier functions

Date: January 22, 2004
Creator: Calzolari, Arrigo; Marzari, Nicola; Souza, Ivo & Buongiorno Nardelli, Marco
Description: Article on ab initio transport properties of nanostructures from maximally localized Wannier functions.
Contributing Partner: UNT College of Arts and Sciences
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