31 Matching Results

Search Results

Rationally designed graphene-nanotube 3D architectures with a seamless nodal junction for efficient energy conversion and storage

Description: This article discusses the development of a strategy of creating 3D graphene-carbon nanotube hollow fibers with radially aligned CNTs (RACNTs) seamless sheathed by a cylindrical graphene layer through a one-step chemical vapor deposition using an anodized aluminum wire template.
Date: September 4, 2015
Creator: Xue, Yuhua; Ding, Yong; Niu, Jianbing; Xia, Zhenhai; Roy, Ajit; Chen, Hao et al.
Partner: UNT College of Engineering

Low-Energy Electron Irradiation of Preheated and Gas-Exposed Single-Wall Carbon Nanotubes

Description: We investigate the conditions under which electron irradiation of single-walled carbon nanotube (SWCNT) bundles with 2 keV electrons produces an increase in the Raman D peak. We find that an increase in the D peak does not occur when SWCNTs are preheated in situ at 600 C for 1 h in ultrahigh vacuum (UHV) before irradiation is performed. Exposing SWCNTs to air or other gases after preheating in UHV and before irradiation results in an increase in the D peak. Small diameter SWCNTs that are not preheated or preheated and exposed to air show a significant increase in the D and G bands after irradiation. X-ray photoelectron spectroscopy shows no chemical shifts in the C1s peak of SWCNTs that have been irradiated versus SWCNTs that have not been irradiated, suggesting that the increase in the D peak is not due to chemisorption of adsorbates on the nanotubes.
Date: December 2016
Creator: Ecton, Philip
Partner: UNT Libraries

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

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.
Date: August 2011
Creator: Shrestha, Ramesh
Partner: UNT Libraries

Structural and electronic properties of carbon nanotube tapers

Description: Article on structural and electronic properties of carbon nanotube tapers, a set of nanostructures comprised of straight tubular sections with decreasing diameters, joined to each other via conical funnels and terminated with a hemispherical cap.
Date: October 29, 2001
Creator: Meunier, Vincent; Buongiorno Nardelli, Marco; Roland, Christopher & Bernholc, Jerry
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

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).
Date: September 17, 2001
Creator: Wadhawan, Atul; Stallcup, Richard E.; Stephens, Kenneth F.; Pérez, José M. & Akwani, Ikerionwu A.
Partner: UNT College of Arts and Sciences

Effective dielectric constants of photonic crystal of aligned anisotropic cylinders and the optical response of a periodic array of carbon nanotubes

Description: This article discusses effective dielectric constants of photonic crystal of aligned anisotropic cylanders and the optical response of a periodic array of carbon nanotubes.
Date: October 25, 2005
Creator: Reyes, E.; Krokhin, Arkadii A. & Roberts, James A.
Partner: UNT College of Arts and Sciences

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

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.
Date: May 2005
Creator: Yang, Zhengtao
Partner: UNT Libraries