Improved hydrothermal synthesis of MoS2 sheathed carbon nanotubes

2012 ◽  
Vol 66 (12) ◽  
Author(s):  
Jaciel Robles-Nuñez ◽  
Fernando Chiñas-Castillo ◽  
Manuel Sanchez-Rubio ◽  
Javier Lara-Romero ◽  
Rafael Huirache-Acuña ◽  
...  

AbstractMoS2 sheathed carbon nanotubes have been successfully synthesized using a hydrothermal route under controlled conditions. The resultant material was studied by XRD, EDS, HRTEM, and Raman spectroscopy. Advantages of the preparation presented here compared to other methods are: a) lower reaction temperature, b) high yield of sheathed nanotubes including ends and full body, c) simple process with non-toxic materials, and d) no damage inflicted to nanotubes.

NANO ◽  
2006 ◽  
Vol 01 (03) ◽  
pp. 251-257 ◽  
Author(s):  
A. A. MUATAZ ◽  
F. AHMADUN ◽  
C. GUAN ◽  
E. MAHDI ◽  
A. RINALDI

A floating catalyst chemical vapor deposition (FC-CVD) method was designed and fabricated to produce high quality and quantity carbon nanotubes. The reaction temperature was optimized to produce high yield and purity of the carbon nanotubes. The reaction temperatures were varied from 500–850°C. The result shows that carbon nanotubes were observed from 600°C to 850°C with maximum numbers and high purity at 850°C. The diameter range of CNTs varied from 2 to 55 nm. The results of the present investigation suggest that the observed changes in catalytic activity and selectivity accompanying an increase in temperature are probably due to major alterations in the distribution of atoms at the metal/gas interface. Thermodynamically, higher temperatures favor the surface decomposition of hydrocarbon rather than the hydrogenation reactions.


2019 ◽  
Vol 16 (2) ◽  
pp. 288-293
Author(s):  
Yogesh W. More ◽  
Sunil U. Tekale ◽  
Nitishkumar S. Kaminwar ◽  
László Kótai ◽  
Tibor Pasinszki ◽  
...  

Aim and Objective: The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. Materials and Methods: Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. Results: The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. Conclusion: Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Kodanda Rama Rao Chebattina ◽  
V. Srinivas ◽  
N. Mohan Rao

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.


2008 ◽  
pp. 2046 ◽  
Author(s):  
Ruitao Lv ◽  
Lin Zou ◽  
Xuchun Gui ◽  
Feiyu Kang ◽  
Yanqiu Zhu ◽  
...  

2011 ◽  
Vol 236-238 ◽  
pp. 241-246 ◽  
Author(s):  
Yuan Bo Huang ◽  
Zhi Feng Zheng ◽  
Hao Feng ◽  
Hui Pan

The resol-type resin was prepared with a high yield from the liquefied products of walnut shell in phenol, which was reacted with formaldehyde under low alkaline conditions. The effects of reaction temperature and time on the yield and viscosity of the resol resin were investigated. Results showed that the optimum resol resinification conditions were a reaction temperature of 80°C and a reaction time of 2 h. The biomass-based resol resin from liquefied products of walnut shell was successfully applied to produce phenolic foam with diisopropyl ether as the blowing agent, Tween 80 as the surfactant and hydrochloric acid as the catalyst, respectively. The obtained foams showed satisfactory mechanical properties and a uniform fine cellular structure.


2015 ◽  
Vol 17 (33) ◽  
pp. 21373-21380 ◽  
Author(s):  
Sabina Botti ◽  
Susanna Laurenzi ◽  
Luca Mezi ◽  
Alessandro Rufoloni ◽  
M. Gabriella Santonicola

By applying SERS, we recorded spectral features from functional molecules bound to the nanotube surface, which are otherwise very difficult to see.


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