scholarly journals A study on the dependence of structure of multi-walled carbon nanotubes on acid treatment

2015 ◽  
Vol 5 (3) ◽  
pp. 287-293 ◽  
Author(s):  
S. Sahebian ◽  
S. M. Zebarjad ◽  
J. vahdati Khaki ◽  
A. Lazzeri
Keyword(s):  
Carbon Nanotubes ◽  
Acid Treatment ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Defect-induced vibrational response of multi-walled carbon nanotubes using resonance Raman spectroscopy

2005 ◽  
Vol 20 (12) ◽  
pp. 3368-3373 ◽  
Author(s):  
S.A. Curran ◽  
J.A. Talla ◽  
D. Zhang ◽  
D.L. Carroll
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Acid Treatment ◽  
Defect Formation ◽  
Double Resonance ◽  
Resonance Raman ◽  
The Body ◽  
Structural Defects ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We systematically introduced defects onto the body of multi-walled carbon nanotubes through an acid treatment, and the evolution of these defects was examined by Raman spectroscopy using different excitation wavelengths. The D and D′ modes are most prominent and responsive to defect formation caused by acid treatment and exhibit dispersive behavior upon changing the excitation wavelengths as expected from the double resonance Raman (DRR) mechanism. Several weaker Raman resonances including D″ and L1 (L2) + D′ modes were also observed at the lower excitation wavelengths (633 and 785 nm). In addition, specific structural defects including the typical pentagon-heptagon structure (Stone–Wales defects) were identified by Raman spectroscopy. In a closer analysis we also observed Haeckelite structures, specifically Ag mode response in R5,7 and O5,6,7.

Effects of acid treatment duration and sulfuric acid molarity on purification of multi-walled carbon nanotubes

Open Physics ◽  
2010 ◽  
Vol 8 (6) ◽  
Author(s):  
Seyedeh Mortazavi ◽  
Abdul Novinrooz ◽  
Ali Reyhani ◽  
Soghra Mirershadi
Keyword(s):  
Carbon Nanotubes ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Treatment Duration ◽  
Acid Treatment ◽  
Bimetallic Catalyst ◽  
Chemical Vapor ◽  
Destructive Effect ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractMulti-walled carbon nanotubes were synthesized using a Fe-Ni bimetallic catalyst supported by MgO using thermal chemical vapor deposition. Purification processes to remove unwanted carbon structures and other metallic impurities were carried out by boiling in sulfuric acid solution. Various analytical techniques such as TGA/DSC, Raman spectroscopy, SEM, HRTEM and EDAX were employed to investigate the morphology, graphitization and quality of the carbon nanotubes. The obtained results reveal the molarity of sulfuric acid and immersed time of the carbon nanotubes in the acid solution is very effective at purifying multi-walled carbon nanotubes. It was also found that 5 M concentration of boiling sulfuric acid for a 3 h treatment duration led to the highest removal of the impurities with the least destructive effect. Moreover, it was observed that acid treatment results in decreasing of CNTs’ diameter.

Preparation and Properties of Polyimide/MWNTs-COOH Antistatic Composites

2014 ◽  
Vol 893 ◽  
pp. 241-244
Author(s):  
Yong Hui Lv ◽  
Bao Xiang Deng
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Acid Treatment ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Good Thermal Stability ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The acidified multi-walled carbon nanotubes (MWNTs-COOH) was obtained by nitric acid treatment on multi-walled carbon nanotubes (MWNTs).The PI/MWNTs-COOH composite films were synthesized by in situ polymerization. The thermal stability, resistance and mechanical properties of PI/MWNTs-COOH composite were evaluated. The results showed that: the composites maintained a good thermal stability with the addition of the MWNTs-COOH; the resistance of the composite film dropped at first, and rose up later. While the tensile strength increased at first and then decreased. In conclusion, the PI/MWNTs-COOH composite films exhibited better thermal, antistatic and mechanical properties compared with neat PI.

Thermo-mechanical properties of epoxy nanocomposites incorporating amino acid and acid functionalized multi-walled carbon nanotubes

2019 ◽  
Vol 54 (14) ◽  
pp. 1847-1861
Author(s):  
Alireza Bagherzade ◽  
Masoud Jamshidi
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Amino Acid ◽  
Epoxy Resin ◽  
Acid Treatment ◽  
Curing Temperature ◽  
Gravimetric Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Functionalized Mwcnts

In this study, multi-walled carbon nanotubes (MWCNTs) were functionalized by both sulfuric/nitric acids and amino acids to form COOH and NH2/COOH/OH groups on their surface, respectively. The functionalized MWCNTs were characterized by Fourier Transform Infrared Spectroscopy, titration test, thermal gravimetric analysis, and solvent stability test. The results revealed that in each method, the functional groups were successfully attached to the surface of nanotubes. Acid treatment grafted more oxygen-containing groups compared to commercial carboxylated MWCNTs. The amino acid functionalized MWCNTs indicated improved stability in different solvents compared to raw and acid treated MWCNTs. These functionalized MWCNTs were incorporated into epoxy resin and the properties of the nanocomposites were evaluated by scanning electron microscopy, tensile test, dynamic mechanical thermal analysis, differential scanning calorimetry, and thermogravimetric analysis. The morphology of the nanocomposites revealed that acid and amino acid treated samples had better interaction with the epoxy resin. Compared to epoxy sample contained raw MWCNT (control) and commercial carboxylated MWCNTs, the addition of functionalized MWCNTs to the epoxy resin improved the tensile strength by 39% and 25% (for acid treated) and 46% and 33% (for amino acid treated), respectively. The best tensile properties for acid and amino acid treated samples were reached by MWCNTs acid treated at 110℃ for 15 min and MWCNTs treated in a 50 g/L aqueous solution of amino acid, respectively. Storage modulus of the epoxy samples which contained acid and amino acid treated MWCNTs were 1560 and 1900 MPa, respectively. The glass rubber transition temperature ( Tg) of the epoxy samples containing acid and amino acid treated nanotubes were increased by 1.1℃ and 5.9℃, respectively, compared to the control sample. Therefore, based on these mechanical properties, the epoxy samples containing nanotubes functionalized by amino acid exhibited the highest performance in the epoxy nanocomposite. Incorporating acid and amino acid treated MWCNTs accelerated the curing process of epoxy where the curing temperature decreased by 9.1℃ and 13.3℃, respectively. Because of the reaction between amine groups grafted on MWCNTs in the amino acid treatment and epoxide groups of the epoxy resin, this acceleration was more significant in the case of amino acid sample. Note that addition of functionalized MWCNTs to epoxy resin did not lead to increased thermal stability.

Mechanochemical Treated Multi-Walled Carbon Nanotubes for Incorporation of Metal Ions

2008 ◽  
Vol 55-57 ◽  
pp. 537-540 ◽  
Author(s):  
U. Rinzin ◽  
Pisith Singjai ◽  
P. Wilairat ◽  
S. Meejoo
Keyword(s):  
Carbon Nanotubes ◽  
Metal Ions ◽  
Acid Treatment ◽  
Room Temperature ◽  
Ni Catalyst ◽  
Linear Least Squares ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Best Fit ◽  
Tubular Form

Ni catalyst was removed from as received multi-walled Carbon Nanotubes (MWNTs) by acid treatment. Then, the nanotubes were treated with 4M HCl during a ball milling processing yielding mechanochemical treated MWNTs (mech-MWNTs). TEM micrographs indicate that the mech-MWNTs were still of a tubular form but with much shorter length. The equilibrium adsorption of metal ions, e.g Cu2+ and Ni2+, on the mech-MWNTs was investigated at room temperature. The adsorption isotherms gave excellent consistence with the Langmuir theory and the best fit values of K-1 and Κmax can be evaluated using non-linear least-squares. As results, the maximum of Cu2+ and Ni2+ ions uptake on to the mech-MWNTs are 0.93 ± 0.004 mg/g and 2.11 ± 0.01 mg/g respectively. There is no evidence indicating that the pore structure and layer surfaces at both ends of the mech-MWNTs are appropriate sites for metal ions adsorption.

scholarly journals Functionalization of single and multi-walled carbon nanotubes by chemical treatment

2019 ◽  
Vol 16 (39) ◽  
pp. 55-63
Author(s):  
Akram Sh. Ahmed
Keyword(s):  
Carbon Nanotubes ◽  
Acid Treatment ◽  
Single Walled Carbon Nanotubes ◽  
Deionized Water ◽  
Acid Oxidation ◽  
Ultrasonic Technique ◽  
Experimental Conditions ◽  
Multi Walled Carbon Nanotubes ◽  
Swcnts And Mwcnts ◽  
Walled Carbon Nanotubes

In this work we experimentally investigated SWCNTs and MWCNTs to increase their thermal conductivity and electrically functionalization process using different reagents ((nitric acid, HNO3 followed by acid treatment with H2SO4), then washed with deionized water (DW) and then treated with H2O2 via ultrasonic technique. Then repeated the steps with MWCNTs and compare their results in an effort to improve experimental conditions that efficiently differentiate the surface of the single walled carbon nanotubes (SWCNTs) and multi walled carbon nanotubesi(MWCNTs) that less nanotubes destroy and to enhance the properties of them and also to reduce aggregation in liquid. the results were prove by XRD, and infrared spectroscopy (FTIR). The FTIR spectrum shows the presence of carboxylic group after treatment with (acid oxidation and H2O2) and refers to Functionalization (SWCNTs) and (MWCNTs) on the surface wall microscopic images show surface adjustment on SWCNTs and ((MWCNTs)) structure after any treatment. AT last, a fully of SWCNTs and MWCNTSIwere obtained successfully accomplished with the reduction of the collapsed structure.

IRON (III) CHLORIDE AS FLOATING CATALYST PRECURSOR TO PRODUCE MULTI-WALLED CARBON NANOTUBES FROM METHANE

NANO ◽  
2010 ◽  
Vol 05 (03) ◽  
pp. 167-173 ◽  
Author(s):  
MEHRNOUSH KHAVARIAN ◽  
SIANG-PIAO CHAI ◽  
SOON HUAT TAN ◽  
ABDUL RAHMAN MOHAMED
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Acid Treatment ◽  
Weight Fraction ◽  
Catalyst Precursor ◽  
Air Oxidation ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Multi-walled carbon nanotubes (MWCNTs) were prepared by floating catalyst (FC) method, using methane as a carbon source and iron (III) chloride ( FeCl3 ) as a catalyst precursor, followed by purification with air oxidation and acid treatment. The as-grown and purified MWCNTs were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetry analysis and Raman spectroscopy. The average inner and outer diameters of the MWCNTs were 25 and 39 nm, respectively. The purity and yield of the purified MWCNTs were more than 92% and 71% weight fraction, respectively.

The influence of acid treatment on multi‐walled carbon nanotubes

2009 ◽  
Vol 38 (3) ◽  
pp. 165-173 ◽  
Author(s):  
X. Jiang ◽  
J. Gu ◽  
X. Bai ◽  
L. Lin ◽  
Y. Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Acid Treatment ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes
Sign in / Sign up

Export Citation Format

Share Document