A Shock and Expansion Wave-driven Powder Disperser

Rajathurai, A.M.; Roth, P.; Fißan, H.

doi:10.1080/02786829008959375

Cited by 22 publications

(9 citation statements)

References 5 publications

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“…The C 60 powder was dispersed in argon by an expansion wave-driven aerosol generator . It consists of a glass vessel of V = 3 ×10 4 cm 3 volume connected to a glass tube of 5 cm inner diameter, which was separated by a thin diaphragm from the high-pressure tube.…”

Section: Methodsmentioning

confidence: 99%

High-Temperature Reactions of Fullerene C₆₀ with H and OH

Sommer¹,

Roth²

1998

J. Phys. Chem. A

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The reactions of H atoms and OH radicals with fullerene C60 were studied behind reflected shock waves by time-dependent absorption measurements. Shock-heated mixtures of C2H5I highly diluted in argon were used as a source for H atoms, and their absorption at λ = 121.6 nm was monitored using the highly sensitive ARAS technique. In a second series of experiments OH radicals were generated in H2/N2O/Ar reaction systems, and the absorption of OH was monitored at ν = 32 403.41 cm-1 using ring dye laser absorption spectroscopy (RDLAS). In each case, the respective mixtures were perturbed by C60. Simultaneously with the absorption measurements, emission spectroscopy with an intensified CCD camera was used to acquire additional information about the reaction systems. The H atom experiments were performed at temperatures between 2100 and 2300 K, while OH absorption was measured in the temperature range 2020 K ≤ T ≤ 2540 K. Postshock pressures were around 1.30 bar for all experiments. From the H-absorption measurements, an upper limit for the reaction C60 + H to products (R9) (k 9 < 1.0 × 1012 cm3 mol-1 s-1) was determined. For the H2/N2O/Ar + C60 reaction system, different kinetic models were discussed to verify the measured OH absorption. The reaction C60 + OH to products (R7) (k 7 = 1.0 × 1015 exp(−6030 K/T) cm3 mol-1 s-1) with the given rate coefficient represents the experimental findings quite well.

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Section: Methodsmentioning

confidence: 99%

High-Temperature Reactions of Fullerene C₆₀ with H and OH

Sommer¹,

Roth²

1998

J. Phys. Chem. A

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“…The C 60 powder was dispersed in argon by an expansion wave driven aerosol generator . It consists of a glass vessel of V = 3 × 10 4 cm 3 volume connected to a glass tube of 5 cm inner diameter, which was separated by a thin diaphragm from a high-pressure tube of the same diameter.…”

Section: Methodsmentioning

confidence: 99%

Perturbation Study on the Reaction of C₂ with N₂ in High-Temperature C₆₀/Ar + N₂ Mixtures

Sommer¹,

Kruse²,

Roth³

et al. 1997

J. Phys. Chem. A

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The reaction of C2 radicals with nitrogen was studied behind reflected shock waves by time dependent absorption and emission measurements. Mixtures of fullerene C60 highly diluted in argon were shock heated and used as C2 sources. Perturbation of the reaction system by addition of N2 results in changes of C2 absorption and causes strong CN emission. The C2 concentration was quantitatively monitored by ring dye laser absorption spectroscopy at ν = 19 355.60 cm-1. Simultaneously, the time behavior of spectrally resolved light emitted from the shock-heated mixtures was recorded by an intensified CCD camera in the wavelength range 315 nm ≤ λ ≤ 570 nm. By comparing the integrated C2 and CN emission signals for the Δv = 0 progressions, the CN concentration can be determined on the basis of the known C2 concentration and the relative line strengths. The experiments were performed in the temperature range 2896 K ≤ T ≤ 3420 K at pressures 1.68 bar ≤ p ≤ 2.03 bar. Evaluation of C2 and CN concentration measurements lead to the following rate coefficient for the reaction C2 + N2 ⇌ CN + CN: k 3 1.5 × 1013 exp(−21 000 K/T) cm3 mol-1 s-1. The uncertainty in k 3 is expected to be ±50%.

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“…Because the matched cone method seemed better suited to high mass concentration throughput, it was selected for this investigation. Rajathurai et al (1990) report successful powder deagglomeration and dispersion with a shock and expansion wave-driven method; this research was not known to us at the initiation of the work reported here. These experiments involved shock and expansion waves created when pressurized gas ruptured a diaphragm.…”

Section: Deagglomeration Technique Selection and Hardware Developmentmentioning

confidence: 99%

“…This approach worked well, with high deagglomeration ef ciencies, for submicron (0.2-0.5 m m count median diameter) quartz and polystyrene latex particles. The research reported by Rajathurai et al (1990) is quite bene cial in terms of elucidating sonic aerodynamic deagglomeration mechanisms, which are also involved in our approach; however, the method we adopted seems to have at least two signi cant advantages when compared to the Rajathurai et al (1990) method: rst, the carrier gas is explicitly controlled and minimized; second, the physical arrangement is amenable to repeated rather than "single-shot" experiments.…”

Section: Deagglomeration Technique Selection and Hardware Developmentmentioning

confidence: 99%

Resuspension of Particles by Aerodynamic Deagglomeration

Fonda¹,

Petach²,

Rogers³

et al. 1999

Aerosol Science and Technology

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ABSTRACT. A deagglomerator system was developed, characterized by laboratory tests, and own under low-gravity (low-g) microgravity conditions. Requirements for a dry powder deagglomeration system were generated by university and National Aeronautics and Space Administration (NASA) scientists from diverse elds of interest including exobiology, planetary sciences, and atmospheric sciences. Existing deagglomeration methods and devices are reviewed. An aerosol generation method suitable for dry powders over a large range of particle sizes and types at high concentrations with consistent deagglomeration ef ciency are evaluated. Development of a pulsed-ow laboratory device and experimental approaches to meet the requirements without being g-dependent are described. Results of laboratory one-g quantitative characterization on one type of dry powder particle generator is discussed. Data from NASA low-g tests are summarized.

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A Shock and Expansion Wave-driven Powder Disperser

Cited by 22 publications

References 5 publications

High-Temperature Reactions of Fullerene C₆₀ with H and OH

High-Temperature Reactions of Fullerene C₆₀ with H and OH

Perturbation Study on the Reaction of C₂ with N₂ in High-Temperature C₆₀/Ar + N₂ Mixtures

Resuspension of Particles by Aerodynamic Deagglomeration

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A Shock and Expansion Wave-driven Powder Disperser

Cited by 22 publications

References 5 publications

High-Temperature Reactions of Fullerene C60 with H and OH

High-Temperature Reactions of Fullerene C60 with H and OH

Perturbation Study on the Reaction of C2 with N2 in High-Temperature C60/Ar + N2 Mixtures

Resuspension of Particles by Aerodynamic Deagglomeration

Contact Info

Product

Resources

About

High-Temperature Reactions of Fullerene C₆₀ with H and OH

High-Temperature Reactions of Fullerene C₆₀ with H and OH

Perturbation Study on the Reaction of C₂ with N₂ in High-Temperature C₆₀/Ar + N₂ Mixtures