Carbon nanopowders from the continuous-wave CO2 laser-induced pyrolysis of ethylene

Morjan, I.; Voicu, I.; Dumitrache, Florian; Sandu, I.; Soare, I.; Alexandrescu, R.; Vasile, Eugeniu; Pasuk, Iuliana; Brydson, Rik; Daniels, H.; Rand, B.

doi:10.1016/s0008-6223(03)00381-6

Cited by 51 publications

(29 citation statements)

References 25 publications

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“…The experimental setup was explained in Morjan et al (2003) and Jäger et al (2006Jäger et al ( , 2009). In the current work, the experiment ran with 60 W radiation of a cw CO 2 laser at a wavelength of 10.6 μm with gas flows of Ar and C 2 H 4 of 1500 sccm (standard cubic centimeters per minute) and 40 sccm, respectively, at a pressure of 750 mbar.…”

Section: Sample Productionmentioning

confidence: 99%

Analogs of solid nanoparticles as precursors of aromatic hydrocarbons

Gadallah

Mutschke

Jäger

2013

A&A

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Context. Aromatic =CH and C=C vibrational bands have been observed within shocked interstellar regions, indicating the presence of aromatic emission carriers such as PAHs, which may have been created from adjacent molecular cloud material by interaction with a shock front. Aims. We investigate the evolution of the aromatic =CH and C=C vibrational modes at 3.3 and 6.2 μm wavelength in heated HAC materials, PAHs and mixed PAHs and HACs, respectively, aiming at an explanation of the evolution of carbonaceous dust grains in the shocked regions. Methods. Materials used in these analogs (HAC and PAH materials) were prepared by the laser ablation and the laser pyrolysis methods, respectively. The transmission electron microscopy (TEM) in high-resolution mode was used as an analytical technique to characterize the aromatic layers in HACs. Spectroscopic analysis was prformed in the mid-IR range. Results. A remarkable destruction of aliphatic structures in HACs has been observed with the thermal processing, while aromatic structures become dominating by increasing the diameters of the graphene layers. The aromatic bands at 3.3 and 6.2 μm, observed in the laboratory spectra of PAHs and of the combination of the PAHs and HAC materials, are also clearly observed in the spectrum of the heated HACs. These bands agree with those of aromatic bands observed in astronomical observations. Conclusions. Aromatization of HACs could be a pre-stage in the decomposition process of hydrocarbons that form PAH-clusters in such hot interstellar medium.

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Section: Sample Productionmentioning

confidence: 99%

Analogs of solid nanoparticles as precursors of aromatic hydrocarbons

Gadallah

Mutschke

Jäger

2013

A&A

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“…Laser-induced pyrolysis of pure hydrocarbons leads to carbon nanopowders with a turbostratic structure [6]. The controlled presence of oxygen in the reactive gas mixture changes drastically the structure to the fullerene-like one (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The carbon sources were hydrocarbons with a high content of C/mole, used either in resonant (ethylene: n 7 = 971 cm À1 ) or non-resonant processes (acetylene: n 5 = 730.3 cm À1 , n 3 = 3281.9 and 3294.9 cm À1 and benzene: n 4 = 673 cm À1 , n 14 = 1038 cm À1 and n 13 = 1486 cm À1 ), when ethylene or sulphur hexafluoride were employed as sensitizer; this energy transfer agent could either react or interfere through its decomposition products, and make the final particle morphology difficult to control experimentally [5]. The experimental set up consists of a high CW CO 2 laser (10P20 emission line at 944 cm À1 ), a stainless steel reaction chamber, gas flow and pressure control systems as well as a powder recovery device [6]. The characteristics of synthesized carbon nanopowders were analysed as a function of the nature of reactant gases and experimental parameters and investigated by electron microscopy (TEM, HREM), and FTIR spectrometry.…”

Section: Methodsmentioning

confidence: 99%

Heterogeneous atoms in laser-induced synthesis of carbon black

Popovici

Florescu

Soare

et al. 2009

Applied Surface Science

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“…An increased laser power leads to an important decreasing of particle's dimensions as the result of higher temperature involved (Fig. 2); particles are well dispersed and present a better graphitised structure [7].…”

Section: Resultsmentioning

confidence: 99%