MORPHOLOGY CONTROL OF CARBON NANOTUBES THROUGH FOCUSED ION BEAMS

NANO ◽  
2008 ◽  
Vol 03 (06) ◽  
pp. 449-454 ◽  
Author(s):  
M. LOYA ◽  
J. E. PARK ◽  
L. H. CHEN ◽  
K. S. BRAMMER ◽  
P. R. BANDARU ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Properties ◽  
Defect Engineering ◽  
Ion Milling ◽  
Induced Changes ◽  
Physical And Chemical ◽  
Multiwall Carbon

This research demonstrates the capability of controlled, focused ion beam (FIB)–assisted tailoring of morphologies in both multiwall carbon nanotubes (CNTs) and Y junction nonlinear CNT systems through defect engineering. We have shown that a 30 keV FIB Ga + ion beam at low ion milling currents of 1 pA can be used to partially reduce the CNT diameter, to provide electrical conduction bottleneck morphologies for linear CNTs, and to introduce both additive and subractive defects at Y junction locations of Y-CNT samples. Our aim is for this work to provide motivation for additional research to determine the effects of ion-beam-induced changes in modulating the physical and chemical properties of nanotubes.

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.

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.

scholarly journals Gas Sensors Based on Locally Heated Multiwall Carbon Nanotubes Decorated with Metal Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
R. Savu ◽  
J. V. Silveira ◽  
A. Alaferdov ◽  
E. Joanni ◽  
A. L. Gobbi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Metallic Nanoparticles ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Multiwall Carbon Nanotubes ◽  
Electrical Contacts ◽  
Metal Nanoparticle ◽  
Chamber Volume ◽  
Testing Chamber ◽  
Metallic Line

We report the design and fabrication of microreactors and sensors based on metal nanoparticle-decorated carbon nanotubes. Titanium adhesion layers and gold films were sputtered onto Si/SiO2substrates for obtaining the electrical contacts. The gold layers were electrochemically thickened until 1 μm and the electrodes were patterned using photolithography and wet chemical etching. Before the dielectrophoretic deposition of the nanotubes, a gap 1 μm wide and 5 μm deep was milled in the middle of the metallic line by focused ion beam, allowing the fabrication of sensors based on suspended nanotubes bridging the electrodes. Subsequently, the sputtering technique was used for decorating the nanotubes with metallic nanoparticles. In order to test the as-obtained sensors, microreactors (100 μL volume) were machined from a single Kovar piece, being equipped with electrical connections and 1/4′′ Swagelok-compatible gas inlet and outlets for controlling the atmosphere in the testing chamber. The sensors, electrically connected to the contact pins by wire-bonding, were tested in the 10−5to 10−2 W working power interval using oxygen as target gas. The small chamber volume allowed the measurement of fast characteristic times (response/recovery), with the sensors showing good sensitivity.

Conductivity Modulation in Polymer Electrolytes and their Composites due to Ion-Beam Irradiation

2015 ◽  
Vol 239 ◽  
pp. 110-148 ◽  
Author(s):  
Divya Singh ◽  
B. Bhattacharya ◽  
Hardev Singh Virk
Keyword(s):  
Polymer Electrolyte ◽  
Polymer Electrolytes ◽  
Ion Beam ◽  
Chemical Properties ◽  
Polymer Properties ◽  
Wide Range ◽  
The Matrix ◽  
Radiation Induced ◽  
Induced Changes ◽  
Physical And Chemical

Polymers are a class of materials widely used in different fields of applications. With imminent applications of polymers, the study of radiation induced changes in polymers has become an obvious scientific demand. The bombardment by ion beam radiations has become one of the most promising techniques in present day polymer research. When the polymers are irradiated, a variety of physical and chemical changes takes place due to energy deposition of the radiation in the polymer matrix. Scissoring, cross-linking, recombination, radical decomposition, etc. are some of the interesting changes that are obvious in polymers. The modification in polymer properties by irradiation depends mainly on the nature of radiation and the type of polymer used.Polymer electrolytes are obtained by modifying polymers by doping, complexing, or other chemical processes. In general, they suffer from low conductivity due to high crystallinity of the matrix. The effect of radiation on polymer electrolyte is expected to alter their crystalline nature vis-a-vis electrical properties. This review article shall elaborate modifications in the physical and chemical properties of polymer electrolytes and their composites. The variations in properties have been explored on PEO based polymer electrolyte and correlated with the parameters responsible for such changes. Also a comparison with different types of the polymers irradiated with a wide range of ion beams has been established.

Fabrication of ball-shaped atomic force microscope tips by ion-beam-induced deposition of platinum on multiwall carbon nanotubes

2009 ◽  
Vol 110 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Yung Ho Kahng ◽  
Jinho Choi ◽  
Kwanghoon Jeong ◽  
Byong Chon Park ◽  
Dal-Hyun Kim ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Force Microscope ◽  
Ion Beam ◽  
Multiwall Carbon Nanotubes ◽  
Atomic Force ◽  
Multiwall Carbon

NANOTOXICITY OF MULTIWALL CARBON NANOTUBES TO A549 CELLS IN VITRO

NANO ◽  
2014 ◽  
Vol 09 (02) ◽  
pp. 1450027 ◽  
Author(s):  
FU-DE WANG ◽  
HUA ZHANG ◽  
CHAN JIN ◽  
HAO LIANG ◽  
YING TANG ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Defense Mechanism ◽  
A549 Cells ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Properties ◽  
Epithelial Cell Line ◽  
Ros Generation ◽  
Imaging Dose ◽  
Multiwall Carbon

Multiwall carbon nanotubes (MWCNTs) have been widely applied in many fields due to the excellent physical and chemical properties. As the production and applications of nanotubes expand, public concern about their potential risks to human health has also raised. Cytotoxicity of MWCNTs was evaluated in this study using a cultured human epithelial cell line A549. Uptake of MWCNTs by cultured A549 cells was observed by TEM imaging. Dose-dependent decrease of cell viability showed the cytotoxicity of MWCNTs. Significant reactive oxygen species (ROS) generation and GSH depletion which reduced the cellular antioxidant level could be the major factor of cytotoxicity induced by MWCNTs. MWCNTs seemed to trigger the activation of cell autophagy with the intracellular ATG16L1 level increase as a defense mechanism.

Boehmite Nanofibers as a Dispersant for Nanotubes in an Aqueous Sol

2018 ◽  
Author(s):  
Gen Hayase
Keyword(s):  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Aqueous Solutions ◽  
High Aspect Ratio ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon ◽  
Nanotube Films

By exploiting the dispersibility and rigidity of boehmite nanofibers (BNFs) with a high aspect ratio of 4 nm in diameter and several micrometers in length, multiwall-carbon nanotubes (MWCNTs) were successfully dispersed in aqueous solutions. In these sols, the MWCNTs were dispersed at a ratio of about 5–8% relative to BNFs. Self-standing BNF–nanotube films were also obtained by filtering these dispersions and showing their functionality. These films can be expected to be applied to sensing materials.

Low Energy Ar Ion Milling of FIB TEM Specimens from 14 nm and Future FinFET Technologies

2018 ◽  
Author(s):  
C.S. Bonifacio ◽  
P. Nowakowski ◽  
M.J. Campin ◽  
M.L. Ray ◽  
P.E. Fischione
Keyword(s):  
Field Effect Transistor ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Effect Transistor ◽  
20 Nm ◽  
Argon Ion

Abstract Transmission electron microscopy (TEM) specimens are typically prepared using the focused ion beam (FIB) due to its site specificity, and fast and accurate thinning capabilities. However, TEM and high-resolution TEM (HRTEM) analysis may be limited due to the resulting FIB-induced artifacts. This work identifies FIB artifacts and presents the use of argon ion milling for the removal of FIB-induced damage for reproducible TEM specimen preparation of current and future fin field effect transistor (FinFET) technologies. Subsequently, high-quality and electron-transparent TEM specimens of less than 20 nm are obtained.

Nanomechanical Characterization in the FIB

2005 ◽  
Author(s):  
Thomas M. Moore
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Materials Characterization ◽  
Depth Of Focus ◽  
Ion Milling ◽  
Nano Technology ◽  
Physical Behavior ◽  
Nanomechanical Testing ◽  
Load Cells ◽  
Scanning Electron

Abstract The availability of the focused ion beam (FIB) microscope with its excellent imaging resolution, depth of focus and ion milling capability has made it an appealing platform for materials characterization at the sub-micron, or "nano" level. This article focuses on nanomechanical characterization in the FIB, which is an extension of the FIB capabilities into the realm of nano-technology. It presents examples that demonstrate the power and flexibility of nanomechanical testing in the FIB or scanning electron microscope with a probe shaft that includes a built-in strain gauge. Loads that range from grams to micrograms are achievable. Calibration is limited only by the availability of calibrated load cells in the smallest load ranges. Deflections in the range of a few nanometers range can be accurately applied. Simultaneous electrical, mechanical, and visual data can be combined to provide a revealing study of physical behavior of complex and dynamic nanostructures.

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