Kinetics of Aerosol Formation During Tungsten Hexacarbonyl Photolysis

Dubtsov, S.N.; Levykin, A.I.; Sabelfeld, Karl K.

doi:10.1016/s0021-8502(99)00539-x

Cited by 11 publications

(13 citation statements)

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“…4. Here, together with correlation (3.1), data from Baron and Willeke (2001), Dubtsov, Dultsev, Ankilov, Levykin, and Sabelfeld (2005), and Reid, Prausnitz, and Sherwood (1977) are also given. In all cases gas temperature was the same, T = 295 ± 2 K. (2001), 4-experimental correlation (Dubtsov et al, 2005), 5-Chapman equation (Reid et al, 1977).…”

Section: Figmentioning

confidence: 99%

Measurements of the temperature dependent diffusion coefficient of nanoparticles in the range of 295–600K at atmospheric pressure

Rudyak

Dubtsov

Baklanov

2009

Journal of Aerosol Science

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Section: Figmentioning

confidence: 99%

Measurements of the temperature dependent diffusion coefficient of nanoparticles in the range of 295–600K at atmospheric pressure

Rudyak

Dubtsov

Baklanov

2009

Journal of Aerosol Science

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“…The Smoluchowski equation was solved for free-molecular collisions of monomers and clusters, similar to those described by Rao and McMurry. 12 An effective algorithm for solving the coagulation equation has been reported earlier by Dubtsov et al 9,10,13 In the present study, this model was modified to account for the influence of t 1 (time gap between the end of irradiation and the moment of particles detection) and diffusion losses of monomer and clusters on the walls of the reactor and pipelines. Similarly to Rao and McMurry, 12 Under these conditions, the dynamics of the particle concentration is described by the following equations where F(t) ) F ) constant at t e t 0 , F(t) ) 0 at t 0 e t e t 0 + t 1 (no monomer formation during t 1 ), ij is the collision constant for clusters, consisting of i and j monomers, N k is the concentration of clusters, consisting of k monomers, t 0 is the irradiation time, and t 1 is the retention time.…”

Section: Numerical Modeling Of Aerosol Formation Kineticsmentioning

confidence: 99%

“…The monomer formation rate value was calculated by a nonlinear least-squares fitting of the calculated curves with experimental data by a technique similar to that described by Dubtsov et al 9,10 Foreign gas affects the rate of monomer formation (F). Thus, in N 2 , F ) 1.48 × 10 7 cm -3 s -1 , which is more than in the N 2 + O 2 mixture (4:1) F ) 0.742 × 10 7 cm -3 s -1 , when water concentration is less than 5.0 × 10 17 molecule/cm 3 .…”

Section: Numerical Modeling Of Aerosol Formation Kineticsmentioning

confidence: 99%

New Nanoparticle Formation under UV Impact on Acetaldehyde Vapor in Nitrogen and Air Flow

et al. 2004

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This paper deals with the study of the kinetics of photolysis and photonucleation of acetaldehyde (AA) vapor in air and in nitrogen along with physical and chemical characteristics of the formed aerosol particles. Free radicals accompanying photonucleation were identified using the electron spin resonance spin-trapping technique. Numerical modeling of the photonucleation kinetics of AA, based on experimental results, was carried out. Rate of generation of primary products, leading to the nanoparticles, and the aerosol yield were evaluated. Chemical mechanism of stages leading to photonucleation in this system was proposed.

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“…6,[8][9][10] Subsequently the numerical modeling was used to interpret the nucleation of magnesium oxide particles, 11,12 silicon dioxide, 13 and formation of aerosol particles in photochemical decomposition of tungsten hexacarbonyl and halobenzenes. 14 The kinetic models used in these studies could be divided into two groups. 15 In the first group are the coagulation models, which contain only irreversible monomer-cluster and cluster-cluster addition reactions.…”

Section: Introductionmentioning

confidence: 99%

Complete thermodynamically consistent kinetic model of particle nucleation and growth: Numerical study of the applicability of the classical theory of homogeneous nucleation

Чесноков

Krasnoperov

2007

The Journal of Chemical Physics

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A complete thermodynamically consistent elementary reaction kinetic model of particle nucleation and growth from supersaturated vapor was developed and numerically evaluated to determine the conditions for the steady-state regime. The model treats all processes recognized in the aerosol science (such as nucleation, condensation, evaporation, agglomerationcoagulation, etc.) as reversible elementary reactions. It includes all possible forward reactions (i.e., of monomers, dimers, trimers, etc.) together with the thermodynamically consistent reverse processes. The model is built based on the Kelvin approximation, and has two dimensionless parameters: S0-the initial supersaturation and Theta-the dimensionless surface tension. The time evolution of the size distribution function was obtained over the ranges of parameters S0 and Theta. At low initial supersaturations, S0, the steady state is established after a delay, and the steady-state distribution function corresponds to the predictions of the classical nucleation theory. At high initial supersaturations, the depletion of monomers due to condensation on large clusters starts before the establishing of the steady state. The steady state is never reached, and the classical nucleation theory is not applicable. The boundary that separates these two regimes in the two dimensionless parameter space, S0 and Theta, was determined. The model was applied to several experiments on water nucleation in an expansion chamber [J. Wolk and R. Strey, J. Phys. Chem. B 105, 11683 (2001)] and in Laval nozzle [Y. J. Kim et al., J. Phys. Chem. A 108, 4365 (2004)]. The conditions of the experiments performed using Laval nozzle (S0=40-120) were found to be close to the boundary of the non-steady-state regime. Additional calculations have shown that in the non-steady-state regime the nucleation rate is sensitive to the rate constants of the initial steps of the nucleation process, such as the monomer-monomer, monomer-dimer, etc., reactions. This conclusion is particularly important for nucleation from supersaturated water vapor, since these processes for water molecules at and below the atmospheric pressure are in the low pressure limit, and the rate constants can be several orders of magnitude lower than the gas kinetic. In addition, the impact of the thermodynamic inconsistency of the previously developed partially reversible kinetic numerical models was assessed. At typical experimental conditions for water nucleation, S0=10 and Theta=10 (T=250 K), the error in the particle nucleation rate introduced by the thermodynamic inconsistency exceeds one order of magnitude.

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Kinetics of Aerosol Formation During Tungsten Hexacarbonyl Photolysis

Cited by 11 publications

References 0 publications

Measurements of the temperature dependent diffusion coefficient of nanoparticles in the range of 295–600K at atmospheric pressure

Measurements of the temperature dependent diffusion coefficient of nanoparticles in the range of 295–600K at atmospheric pressure

New Nanoparticle Formation under UV Impact on Acetaldehyde Vapor in Nitrogen and Air Flow

Complete thermodynamically consistent kinetic model of particle nucleation and growth: Numerical study of the applicability of the classical theory of homogeneous nucleation

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