Gas-Phase PVT Properties and Vapor Pressures of Pentafluoroethane (HFC-125) Determined According to the Burnett Method

1995 ◽  
Vol 40 (1) ◽  
pp. 148-152 ◽  
Author(s):  
Fang Ye ◽  
Haruki Sato ◽  
Koichi Watanabe
Keyword(s):  
Gas Phase ◽  
Vapor Pressures ◽  
Pvt Properties ◽  
Burnett Method

Vapor pressures and PVT properties of 1,1,1,3,3-pentafluoropropane (HFC-245fa)

1999 ◽  
Vol 161 (2) ◽  
pp. 325-335 ◽  
Author(s):  
Tomohiro Sotani ◽  
Hironobu Kubota
Keyword(s):  
Vapor Pressures ◽  
Pvt Properties

Mass Spectrometric Studies of Physical, Thermochemical and Reactive Properties of Xenon Fluorides, Xenon Oxides and Xenon Oxyfluorides

2002 ◽  
Vol 8 (3) ◽  
pp. 233-246 ◽  
Author(s):  
Vladislav V. Zelenov ◽  
Elena V. Aparina ◽  
Alexander V. Loboda ◽  
Alexander S. Kukui ◽  
Alexander F. Dodonov ◽  
...  
Keyword(s):  
Gas Phase ◽  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Saturated Vapor ◽  
Electron Impact Ionization ◽  
Binding Energies ◽  
Ionization Mass ◽  
Vapor Pressures ◽  
Gas Phase Reactions

Using a reactor with a flowing diffusion cloud coupled to a high-resolution, low-energy electron-impact ionization mass spectrometer, mechanistic, kinetic and thermochemical characteristics of gas-phase reactions with the participation of charged and neutral xenon oxides, xenon fluorides and xenon oxyfluorides have been investigated. Ionization energies for XeF, XeF2, XeF4, XeO3, XeO4, XeOF4 molecules and appearance energies for the ions formed from these molecules were obtained. Based on experimental and reference data, the enthalpies of XeO3 and XeOF4 formation were refined and a number of binding energies in the parent and fragment ions were calculated. For electron-impact ionization, the ionization cross-sections for Xe, XeF2, XeF4 and XeOF4 proved to correlate with a semi-empirical principle of full ionization. Based on the temperature dependencies of saturated vapor pressures for XeO4, XeOF4 and XeO2F2, their enthalpies of evaporation, sublimation and melting were determined. The mechanisms of gas-phase reactions between H atoms and neutral XeF2, XeF4, XeF6, XeO4 and XeOF4 were studied.

SiC HTCVD Simulation Modified by Sublimation Etching

2006 ◽  
Vol 527-529 ◽  
pp. 107-110 ◽  
Author(s):  
Yasuo Kito ◽  
Emi Makino ◽  
Kei Ikeda ◽  
Masao Nagakubo ◽  
Shoichi Onda
Keyword(s):  
Gas Phase ◽  
Reaction Rates ◽  
Reaction Model ◽  
Inductive Heating ◽  
Present Calculation ◽  
Quasi Equilibrium ◽  
Phase Reaction ◽  
Vapor Pressures ◽  
Gas Phase Reaction ◽  
Sticking Coefficients

High temperature chemical vapor deposition (HTCVD) simulations of silicon carbide (SiC) were demonstrated with experimental results. A vertical cylindrical reactor was used in an RF inductive heating furnace and the temperature was more than 2200. SiH4 and C3H8 were used as source gases and H2 as carrier gas. A gas phase reaction model from the literature was used on the condition that the gas phase reaction is a quasi-equilibrium state. It was found that the major species were Si, Si2C, SiC2 and C2H2 in the gas phase reaction model as well as in the thermodynamic equilibrium calculation. Sublimation etching was considered in the surface reaction rates by modifying partial pressures of species with equilibrium vapor pressures. CFD-ACE+ and MALT2 software packages were used in the present calculation. The sticking coefficients were determined by fitting the calculated growth rates to the experimental ones. The simulated growth rate in a different reactor is in good agreement with the experimental value, using the same sticking coefficients. The present simulation could be useful to design a new reactor and to find optimum conditions.

scholarly journals Model for acid-base chemistry in nanoparticle growth (MABNAG)

2013 ◽  
Vol 13 (3) ◽  
pp. 7175-7222 ◽  
Author(s):  
T. Yli-Juuti ◽  
K. Barsanti ◽  
L. Hildebrandt Ruiz ◽  
A.-J. Kieloaho ◽  
U. Makkonen ◽  
...  
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Gas Phase ◽  
Organic Compounds ◽  
Particle Growth ◽  
Particle Phase ◽  
Vapor Pressures ◽  
Salt Formation ◽  
Acid Base ◽  
Nanoparticle Growth

Abstract. Climatic effects of newly-formed atmospheric secondary aerosol particles are to a large extent determined by their condensational growth rates. However, all the vapors condensing on atmospheric nanoparticles and growing them to climatically relevant sizes are not identified yet and the effects of particle phase processes on particle growth rates are poorly known. Besides sulfuric acid, organic compounds are known to contribute significantly to atmospheric nanoparticle growth. In this study a particle growth model MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) was developed to study the effect of salt formation on nanoparticle growth, which has been proposed as a potential mechanism lowering the equilibrium vapor pressures of organic compounds through dissociation in the particle phase and thus preventing their evaporation. MABNAG is a model for monodisperse aqueous particles and it couples dynamics of condensation to particle phase chemistry. Non-zero equilibrium vapor pressures, with both size and composition dependence, are considered for condensation. The model was applied for atmospherically relevant systems with sulfuric acid, one organic acid, ammonia, one amine and water in the gas phase allowed to condense on 3–20 nm particles. The effect of dissociation of the organic acid was found to be small under ambient conditions typical for a boreal forest site, but considerable for base-rich environments (gas phase concentrations of about 1010 cm−3 for the sum of the bases). The contribution of the bases to particle mass decreased as particle size increased, except at very high gas phase concentrations of the bases. The relative importance of amine versus ammonia did not change significantly as a function of particle size. While our results give a reasonable first estimate on the maximum contribution of salt formation to nanoparticle growth, further studies on, e.g. the thermodynamic properties of the atmospheric organics, concentrations of low-volatility organic acids and amines, along with studies investigating the applicability of thermodynamics for the smallest nanoparticles are needed to truly understand the acid-base chemistry of atmospheric nanoparticles.

scholarly journals Vapor Pressures and PVT Properties of HFE-245mc(pentafluoroethyl methyl ether).

1998 ◽  
Vol 7 ◽  
pp. 1198-1200 ◽  
Author(s):  
Toshihide Tsuge ◽  
Haruki Sato ◽  
Koichi Watanabe
Keyword(s):  
Methyl Ether ◽  
Vapor Pressures ◽  
Pvt Properties

New Zinc-bis(Dialkylamides) Potentially Usable as Site-Selective Dopants For p-Type ZnSe.

1993 ◽  
Vol 334 ◽  
Author(s):  
William S. Rees ◽  
Oliver Just
Keyword(s):  
Vapor Pressure ◽  
Gas Phase ◽  
Elemental Analysis ◽  
Vapor Pressures ◽  
Effective Utilization ◽  
Site Selectivity ◽  
A Site ◽  
P Type ◽  
Site Selective ◽  
C Nmr

AbstractIn earlier work, the effective utilization of Zn {N\Si(CH3)3]2}2 as a site-selective dopant for the production of p-type ZnSe by OMVPE was demonstrated. Several new zinc-bis(dialkylamides) of the general form (R)(R′)NZnN(R″)(R‴) now have been prepared. They have been characterized by 1H- and 13C-NMR, GC/MS and elemental analysis. Vapor pressures and gas phase decompositior profiles have been examined. Correlations of vapor pressure and structure are discussed for this series of compounds. A mechanism for the site-selectivity observed in the incorporation of nitrogen is proposed.

Sign in / Sign up

Export Citation Format

Share Document