scholarly journals Dispersion of Carbon Nanotubes with “Green” Detergents

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2908
Author(s):  
Kazuo Umemura ◽  
Ryo Hamano ◽  
Hiroaki Komatsu ◽  
Takashi Ikuno ◽  
Eko Siswoyo
Keyword(s):  
Carbon Nanotubes ◽  
Sodium Dodecyl ◽  
Detergent Solution ◽  
Absorbance Spectroscopy ◽  
Fundamental Research ◽  
The Stability ◽  
Single Walled Cnts ◽  
Better Than ◽  
Walled Cnts ◽  
Cnt Suspensions

Solubilization of carbon nanotubes (CNTs) is a fundamental technique for the use of CNTs and their conjugates as nanodevices and nanobiodevices. In this work, we demonstrate the preparation of CNT suspensions with “green” detergents made from coconuts and bamboo as fundamental research in CNT nanotechnology. Single-walled CNTs (SWNTs) with a few carboxylic acid groups (3–5%) and pristine multi-walled CNTs (MWNTs) were mixed in each detergent solution and sonicated with a bath-type sonicator. The prepared suspensions were characterized using absorbance spectroscopy, scanning electron microscopy, and Raman spectroscopy. Among the eight combinations of CNTs and detergents (two types of CNTs and four detergents, including sodium dodecyl sulfate (SDS) as the standard), SWNTs/MWNTs were well dispersed in all combinations except the combination of the MWNTs and the bamboo detergent. The stability of the suspensions prepared with coconut detergents was better than that prepared with SDS. Because the efficiency of the bamboo detergents against the MWNTs differed significantly from that against the SWNTs, the natural detergent might be useful for separating CNTs. Our results revealed that the use of the “green” detergents had the advantage of dispersing CNTs as well as SDS.

Various Nanotube Scaffolds for Cell Proliferation

2009 ◽  
Vol 631-632 ◽  
pp. 181-186 ◽  
Author(s):  
Fumio Watari ◽  
T. Akasaka ◽  
K. Ishikawa ◽  
M. Matsuoka ◽  
E. Hirata ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cell Proliferation ◽  
Body Fluid ◽  
Biomedical Applications ◽  
Cell Edge ◽  
The One ◽  
Single Walled Cnts ◽  
Cells Cultured ◽  
Walled Cnts ◽  
Multiwalled Cnts

Carbon nanotubes (CNT) and their derivatives with different structure and compositions have unique features. In the present study, cell proliferation was performed on various nanotubes such as single walled CNTs, multiwalled CNTs and imogolite which is nanotubes of aluminosilicate. SEM observation of the growth of osteoblast-like cells cultured on CNTs showed the morphology fully developed for the whole direction, which was different from that extended to the one direction on the usual scaffold. Numerous filopodia were grown from cell edge, extended far long and combined with CNT meshwork. Apatite precipitation in simulated body fluid, affinity for proteins and saccharides, and nanosize meshwork structure with large porosity would be the properties responsible for these cell adhesion and growth. Imogolite showed the similar properties to CNTs. Nanotubes could be the favorable materials for biomedical applications.

scholarly journals Elucidation of Antimicrobial Activity of Non-Covalently Dispersed Carbon Nanotubes

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1676 ◽  
Author(s):  
Mansab Ali Saleemi ◽  
Mohammad Hosseini Fouladi ◽  
Phelim Voon Chen Yong ◽  
Eng Hwa Wong
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Antimicrobial Activity ◽  
Growth Inhibition ◽  
Microbial Growth ◽  
Sodium Dodecyl ◽  
Surfactant Solution ◽  
Microbial Growth Inhibition ◽  
The Impact ◽  
Walled Cnts

Microorganisms have begun to develop resistance because of inappropriate and extensive use of antibiotics in the hospital setting. Therefore, it seems to be necessary to find a way to tackle these pathogens by developing new and effective antimicrobial agents. Carbon nanotubes (CNTs) have attracted growing attention because of their remarkable mechanical strength, electrical properties, and chemical and thermal stability for their potential applications in the field of biomedical as therapeutic and diagnostic nanotools. However, the impact of carbon nanotubes on microbial growth has not been fully investigated. The primary purpose of this research study is to investigate the antimicrobial activity of CNTs, particularly double-walled and multi-walled nanotubes on representative pathogenic strains such as Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae, and fungal strain Candida albicans. The dispersion ability of CNT types (double-walled and multi-walled) treated with a surfactant such as sodium dodecyl-benzenesulfonate (SDBS) and their impact on the microbial growth inhibition were also examined. A stock concentration 0.2 mg/mL of both double-walled and multi-walled CNTs was prepared homogenized by dispersing in surfactant solution by using probe sonication. UV-vis absorbance, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were used for the characterization of CNTs dispersed in the surfactant solution to study the interaction between molecules of surfactant and CNTs. Later, scanning electron microscopy (SEM) was used to investigate how CNTs interact with the microbial cells. The antimicrobial activity was determined by analyzing optical density growth curves and viable cell count. This study revealed that microbial growth inhibited by non-covalently dispersed CNTs was both depend on the concentration and treatment time. In conclusion, the binding of surfactant molecules to the surface of CNTs increases its ability to disperse in aqueous solution. Non-covalent method of CNTs dispersion preserved their structure and increased microbial growth inhibition as a result. Multi-walled CNTs exhibited higher antimicrobial activity compared to double-walled CNTs against selected pathogens.

scholarly journals Measurement and study of thermophysical properties of nanofluids with carbon nanotubes

2021 ◽  
Vol 2119 (1) ◽  
pp. 012117
Author(s):  
V Ya Rudyak ◽  
G R Dashapilov ◽  
A A Shupik
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Thermophysical Properties ◽  
Weight Concentration ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Single Walled Cnts ◽  
Walled Cnts

Abstract This article is devoted to the study of the thermophysical properties of nanofluids with single-walled and multi-walled carbon nanotubes (CNT). Their weight concentration varied from 0.05 to 0.2%. Nanofluids, based on ethylene glycol and water, were studied. Dispersants were also used. The diffusion of CNT had been systematically investigated by the method of dynamic light scattering and their effective hydrodynamic dimensions were determined. The rheology and viscosity of all nanofluids were studied. It is shown that nanofluids are either pseu-doplastic or viscoplastic. Their rheology changes with increasing CNT concentration and temperature. However, in all cases, the viscosity of nanofluids with single-walled CNTs is signifi-cantly higher than that of nanofluids with multi-walled CNTs. In the last part, the electrical conductivity of all these nanofluids and the dispersants effect on it are investigated.

Controlled Deposition and Applied Field Alignment of Single Walled Carbon Nanotubes for CNT Device Fabrication.

2002 ◽  
Vol 739 ◽  
Author(s):  
Jan Smits ◽  
Buzz Wincheski ◽  
JoAnne Ingram ◽  
Neal Watkins ◽  
Jeff Jordan
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Transport ◽  
Device Fabrication ◽  
Self Assembled Monolayer ◽  
Si Substrates ◽  
Metallic Contacts ◽  
Controlled Deposition ◽  
Walled Carbon Nanotubes ◽  
Single Walled Cnts ◽  
Walled Cnts

ABSTRACTCarbon nanotubes (CNTs) offer great potential for advanced sensing devices due to their unique electronic transport properties. However, a significant obstacle to the realization of practical CNT devices is the formation of controlled, reliable and reproducible CNT to metallic contacts. In this work, a procedure for the deposition and alignment of CNTs onto metallic electrodes using chemically functionalized lithographic patterns is reported. This method uses photo and electron beam lithography to pattern simple Cr/Au thin film circuits on oxidized Si substrates. The circuits are then re-patterned with a self-assembled monolayer (SAM) of 3-aminopropyltriethoxysilane (APTES) to specify desired CNT locations between electrodes. The application of an electric field to the metallic contacts during the deposition of solution suspended single walled CNTs causes alignment of the CNTs in the field direction. This method consistently produces aligned CNTs in the defined locations.

scholarly journals Antimicrobial Effect of Multilayered Carbon Nanotubes on Multi-Drug-Resistant Pseudomonas aeruginosa

2019 ◽  
Author(s):  
Hadis Mousavi ◽  
Hamideh Rouhani Nejad ◽  
Masoud Zandi ◽  
Amir Khodavirdi Pour
Keyword(s):  
Carbon Nanotubes ◽  
Pseudomonas Aeruginosa ◽  
Defense Mechanisms ◽  
Methicillin Resistance ◽  
Antimicrobial Effect ◽  
Inhibitory Effect ◽  
Drug Resistant ◽  
Minimal Inhibitory Concentrations ◽  
Single Walled Cnts ◽  
Walled Cnts

Background: Pseudomonas aeruginosa is the primary cause of infection with impaired defense mechanisms. P. aeruginosa commonly causes nosocomial infections and is the most common pathogen isolated from patients hospitalized for longer than 1 week. We examined the antimicrobial effect of multilayered carbon nanotubes on multi-drug-resistant. Materials and Methods: In this research, 20 clinical isolates collected at Motahari Hospital (Tehran, Iran) were compared with the standard (ATCC 27853) and identified as P. aeruginosa based on biochemical testing. Conventional disk diffusion assay demonstrated the methicillin resistance of the isolates. Minimal inhibitory concentrations for antibiotics and the multilayer CNTs were determined using the microdilution method. Single-walled CNTs were prepared and their efficacy and potential synergism with antibiotics was assessed. Results: Synergism against P. aeruginosa was evident for methicillin + single-walled CNTs. Conclusion: The inhibitory effect of single-walled CNTs and methicillin was synergistic against the growth of P. aeruginosa.

CMOS Compatible Growth of Carbon Nanotubes and Their Application in Field-Effect Transistors

2012 ◽  
Vol 1407 ◽  
Author(s):  
T. Uchino ◽  
G. N. Ayre ◽  
D. C. Smith ◽  
J. L. Hutchison ◽  
C. H. de Groot ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Field Effect ◽  
Defect Density ◽  
Field Effect Transistors ◽  
State Of The Art ◽  
Chemical Vapor ◽  
Radial Breathing Mode ◽  
Metal Catalyst ◽  
Single Walled Cnts ◽  
Walled Cnts

ABSTRACTThe metal-catalyst-free growth of carbon nanotubes (CNTs) using chemical vapor deposition and the application in field-effect transistors (FETs) is presented. The CNT growth process used a 3-nm-thick Ge layer on SiO2 that was subsequently annealed to produce Ge nanoparticles. Raman measurements show the presence of radial breathing mode (RBM) peaks and the absence of the disorder induced D-band, indicating single walled CNTs (SWNTs) with a low defect density. The synthesized CNTs are used to fabricate CNTFETs and the best device has a state-of-the-art on/off current ratio of 3×108 and a steep sub-threshold slope of 110 mV/decade.

scholarly journals Shielding effects in thin films of carbon nanotubes within microwave range

2016 ◽  
Vol 56 (2) ◽  
Author(s):  
Alesia Paddubskaya ◽  
Mikhail Shuba ◽  
Gintaras Valušis ◽  
Polina Kuzhir ◽  
Sergey Maksimenko ◽  
...  
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Microwave Frequency ◽  
Microwave Range ◽  
Different Types ◽  
Em Field ◽  
Shielding Properties ◽  
Single Walled Cnts ◽  
Shielding Effects ◽  
Walled Cnts

The electromagnetic shielding properties of thin films comprising different types of carbon nanotubes (CNTs) were analysed in the microwave frequency range (26–36 GHz). A comparative analysis of the shielding properties was achieved for films based on long and short single-, double- and multi-walled CNTs. The experimental results proved that long-length single-walled CNTs demonstrate the highest interaction with the electromagnetic (EM) field, thereby providing the best shielding efficiency. At the same time, double-walled CNTs demonstrate a higher level of absorption ability (50%) along with the overall high EM shielding efficiency (88%), which makes them attractive for using in nanoelectronics screens as they produce the smallest secondary EM pollution.

FABRICATION OF CARBON NANOTUBE FIELD EFFECT TRANSISTORS WITH OCMC DISPERSED SINGLE-WALLED CARBON NANOTUBES

2010 ◽  
Vol 09 (04) ◽  
pp. 377-381
Author(s):  
KUMAR RAJ ◽  
QING ZHANG ◽  
LIANGYU YAN ◽  
MARY B. CHAN PARK
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Single Walled Carbon Nanotubes ◽  
Oxygen Adsorption ◽  
P Type ◽  
Walled Carbon Nanotubes ◽  
Single Walled Cnts ◽  
Walled Cnts

We report on the fabrication of carbon nanotube field effect transistors (CNTFETs) from dispersed single-walled CNTs using OCMC (O-Carboxymethylchitosan) as the surfactant. The as-prepared devices exhibit p-type as well as ambipolar characteristics due to oxygen adsorption at the metal/nanotube contacts. The Raman scattering from the SWCNTs shows that OCMC disperses CNTs efficiently. Rapid thermal annealing (RTA) at 400°C for 5 min is found to partially remove OCMC from the surface of SWCNTs.

Effect of MoO3 as conditioning catalyst on synthesis of carbon nanotubes

2009 ◽  
Vol 24 (4) ◽  
pp. 1307-1310 ◽  
Author(s):  
Yunfang Liu ◽  
Kenji Takeuchi ◽  
Ki Chul Park ◽  
Hiroyuki Muramatsu ◽  
Tomoyuki Fukuyo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Weight ◽  
Reactive Species ◽  
High Yield ◽  
Layer Number ◽  
Yield Formation ◽  
Synthesis Of Carbon Nanotubes ◽  
Reactive Hydrocarbon ◽  
Single Walled Cnts ◽  
Walled Cnts

The effect of nonsupported MoO3 as a conditioning catalyst on the preparation of carbon nanotubes (CNTs) using a common main catalyst Fe/MgO was investigated. Without using MoO3, only single-walled CNTs were produced at low yield. In contrast, the use of MoO3 provided single-walled and double-walled CNTs at high yield. The MoO3 conditioning catalyst enhances not only the yield but also the diameter and layer number of CNTs. The higher yield formation of more layered CNTs with larger diameter would be attributed to the preproduction of reactive hydrocarbon species by the conditioning catalyst and their growth to larger molecular-weight reactive species.

scholarly journals Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Kodanda Rama Rao Chebattina ◽  
V. Srinivas ◽  
N. Mohan Rao
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Ball Milling ◽  
Multiwalled Carbon Nanotubes ◽  
Tribological Properties ◽  
Extreme Pressure ◽  
Multiwalled Carbon ◽  
Pristine Mwcnts ◽  
Gear Oil ◽  
The Stability

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

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