Synthesis of Multiwalled Carbon Nanotubes

ABSTRACTIn a recent publication we have described the synthesis of multiwalled carbon nanotubes (MWNTs) by the reaction of a hydrocarbon vapor over a dispersed iron catalyst that is deposited in situ on quartz substrates. Our system configuration involves entraining a mixture of xylene and ferrocene into an inert gas stream. Decomposition of the ferrocene at temperatures in the range 625-775 °C, and at atmospheric pressure, produces a coating of iron nanoparticles on the quartz surfaces, and these metal sites function as catalysts for the formation and growth of MWNTs. In this study, we report the influence of operating conditions on MWNT purity and yield. These parameters include the feed injection temperature, furnace temperature, hydrocarbon partial pressure, reaction time, space velocity, and iron to carbon ratio in the feed. We observed that the quality of the MWNTs dependc sensitively on the growth parameters and a window for the operating conditions is identified for the growth of high purity aligned MWNTs. Characterization of the MWNTs by electron microscopy has shown that there is a relationship between metal particle size and MWNT diameter.

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Controllable Loading of Noble Metal Nanoparticles on Multiwalled Carbon Nanotubes/Fe3O4through an In Situ Galvanic Replacement Reaction for High-Performance Catalysis

ChemCatChem ◽

10.1002/cctc.201402167 ◽

2014 ◽

Vol 6 (7) ◽

pp. 1868-1872 ◽

Cited By ~ 16

Author(s):

Shu-Liang Yang ◽

Chang-Yan Cao ◽

Fang-Fang Wei ◽

Pei-Pei Huang ◽

Yong-Bin Sun ◽

...

Keyword(s):

Carbon Nanotubes ◽

Metal Nanoparticles ◽

Multiwalled Carbon Nanotubes ◽

High Performance ◽

Noble Metal Nanoparticles ◽

Galvanic Replacement ◽

Galvanic Replacement Reaction ◽

Replacement Reaction ◽

Multiwalled Carbon

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Multiwalled Carbon Nanotubes Covered with Cobalt (II) Phthalocyanine by In Situ Synthesis and its Electrochemical Sensing Performance towards DA and UA

Materials Science Forum ◽

10.4028/www.scientific.net/msf.809-810.43 ◽

2014 ◽

Vol 809-810 ◽

pp. 43-52

Author(s):

Hua Hua Wang ◽

Nan Li ◽

Kai Li ◽

Yuan Bu ◽

Wen Le Dai ◽

...

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Photoelectron Spectroscopy ◽

Simultaneous Detection ◽

Thick Layer ◽

Electrochemical Sensing ◽

Multiwalled Carbon ◽

X Ray ◽

Platinum Particles

Multiwalled carbon nanotubes (MWCNTs) as an excellent supporter covered with a thick layer of cobalt phthalocyanine (CoPc) were prepared by in-situ synthesis. Platinum particles were adopted to enhance the conductivity of CoPc-MWCNTs. The final nanocomposite Pt-CoPc-MWCNTs was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Strong aromatic π-π stacking between MWCNTs and CoPc made CoPc in-situ forming on MWCNTs. With homogeneous thickness of CoPc covered on the MWCNTs and Pt particles equally distributed, the nanocomposite was used as electrocatalyst. The electrochemical properties of the composite got researched by casting the dispersion of Pt-CoPc-MWCNTs on the glassy carbon electrode. Compared with other modified electrodes, Pt-CoPc-MWCNTs/GC electrode exhibited excellent electrochemical activity towards dopamine (DA) and uric acid (UA). Linear responses for DA and UA were obtained in the ranges of 5 to 170 μM and 5 to 100 μM, and limits of detection were 2.6 and 1.4 μM (S/N= 3), respectively. Simultaneous detection of DA and UA in the presence of ascorbic acid (AA) also displayed selective property, with no interference to each other.

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Miniemulsion copolymerization of (meth)acrylates in the presence of functionalized multiwalled carbon nanotubes for reinforced coating applications

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.134 ◽

2017 ◽

Vol 8 ◽

pp. 1328-1337 ◽

Cited By ~ 4

Author(s):

Bertha T Pérez-Martínez ◽

Lorena Farías-Cepeda ◽

Víctor M Ovando-Medina ◽

José M Asua ◽

Lucero Rosales-Marines ◽

...

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Miniemulsion Polymerization ◽

Polymer Chains ◽

Multiwalled Carbon ◽

Neat Polymer ◽

In Situ Composites ◽

3D Network ◽

Insoluble Polymer

Film forming, stable hybrid latexes made of methyl metacrylate (MMA), butyl acrylate (BA) and 2-hydroxyethyl methacrylate (HEMA) copolymer reinforced with modified multiwalled carbon nanotubes (MWCNTs) were synthesized by in situ miniemulsion polymerization. The MWCNTs were pretreated by an air sonication process and stabilized by polyvinylpyrrolidone. The presence of the MWCNTs had no significant effect on the polymerization kinetics, but strongly affected the polymer characteristics (T g and insoluble polymer fraction). The performance of the in situ composites was compared with that of the neat polymer dispersion as well as with those of the polymer/MWCNT physical blends. The in situ composites showed the presence of an additional phase likely due to the strong interaction between the polymer and MWNCTs (including grafting) that reduced the mobility of the polymer chains. As a result, a substantial increase of both the storage and the loss moduli was achieved. At 60 °C, which is above the main transition region of the polymer, the in situ composites maintained the reinforcement, whereas the blends behaved as a liquid-like material. This suggests the formation of a 3D network, in good agreement with the high content of insoluble polymer in the in situ composites.

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