Homogeneous Nucleation of Supersaturated Vapors. A Comparison of Experimental Results with Theory

1993 ◽  
Vol 58 (12) ◽  
pp. 2831-2835
Author(s):  
Jiří Smolík ◽  
Vladimír Ždímal
Keyword(s):  
Stearic Acid ◽  
Phthalic Anhydride ◽  
Homogeneous Nucleation ◽  
Liquid Droplet ◽  
Experimental Results ◽  
Droplet Model ◽  
Polar Substance ◽  
Ethylhexyl Phthalate

Some theories of homogeneous nucleation based on liquid droplet model were tested by comparing with experimental supersaturations of naphthalene, phthalic anhydride, stearic acid, bis(2-ethylhexyl) phthalate, and bis(2-ethylhexyl) sebacate required to bring about the rate of homogeneous nucleation of about 5 drops/cm3 s-1. It was found that except for highly polar substance phthalic anhydride, the classical (Becker-Doring) theory of homogeneous nucleation, if suitably scaled, yielded fairly good predictions of the nucleation behaviour.

Condensation of supersaturated vapours. Homogeneous nucleation of naphthalene and phthalic anhydride

1985 ◽  
Vol 50 (6) ◽  
pp. 1349-1358 ◽  
Author(s):  
Jiří Smolík ◽  
Jaroslav Vítovec
Keyword(s):  
Surface Tension ◽  
Thermal Diffusion ◽  
Classical Theory ◽  
Phthalic Anhydride ◽  
Homogeneous Nucleation ◽  
Corresponding States ◽  
Experimental Results ◽  
Critical Supersaturation ◽  
Fluid Behaviour ◽  
Good Agreement

The critical supersaturation required for the homogeneous nucleation of naphthalene and phthalic anhydride from their vapours has been measured using upward thermal diffusion cloud chamber. The results obtained are compared with the predictions of the classical theory of homogeneous nucleation (Volmer-Becker-Doring-Zeldovich) and the corresponding states correlation of homogeneous nucleation. The classical theory is found to be in excellent agreement with the experimental results on naphthalene but overpredicts the critical supersaturation of phthalic anhydride vapours by about 30%. In order to fit the experiment and theory, the new values of surface tension of phthalic anhydride were recalculated from the theory. Critical supersaturation of naphthalene plotted versus temperature reveals the same regular departure from single fluid behaviour as found for alkylbenzenes. The experimental results on phthalic anhydride were found to be in very good agreement with the corresponding states correlation.

Nucleation and Growth of Bubbles in Elastomers

1971 ◽  
Vol 44 (5) ◽  
pp. 1363-1379 ◽  
Author(s):  
Charles W. Stewart
Keyword(s):  
Surface Tension ◽  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Experimental Results ◽  
Dissolved Gas ◽  
Rate Of Growth ◽  
High Degree ◽  
Approximate Expressions ◽  
Temperature Surface

Abstract The theory of homogeneous nucleation of bubbles is combined with an expression, for their rate of growth in elastomers to obtain approximate expressions for calculating the number of bubbles formed under a high degree of supersaturation. Experimental results are given for several elastomers with argon as the dissolved gas under a variety of foaming conditions. The theory adequately describes the manner in which the number of bubbles formed depends on the temperature, surface tension of the polymer, and permeability of the dissolved gas.

scholarly journals Laboratory studies of the homogeneous nucleation of iodine oxides

2004 ◽  
Vol 4 (1) ◽  
pp. 19-34 ◽  
Author(s):  
J. B. Burkholder ◽  
J. Curtius ◽  
A. R. Ravishankara ◽  
E. R. Lovejoy
Keyword(s):  
Boundary Layer ◽  
Homogeneous Nucleation ◽  
Marine Boundary Layer ◽  
Coastal Region ◽  
Field Measurements ◽  
Experimental Results ◽  
Model Parameters ◽  
Model Calculations ◽  
Aerosol Model ◽  
Iodine Oxides

Abstract. Laboratory experimental results of iodine oxide nucleation are presented. Nucleation was induced following UV photolysis of CF3I or CH2I2 in the presence of excess ozone. Measurements were performed in a 70 L Teflon reactor with new particles detected using an Ultrafine Condensation Particle Counter, UCPC. The experimental results are interpreted using a coupled chemical - aerosol model to derive model parameters assuming single component homogeneous nucleation of OIO. The aerosol model results have been applied in an atmospheric box-model to interpret the possible implications of iodine oxide nucleation in the marine boundary layer. The model calculations demonstrate that IO and OIO concentrations reported in recent field measurements using long path absorption (Allan et al., 2000, 2001) are not sufficient to account for significant aerosol production either in the coastal or open ocean marine boundary layer using the mechanism presented. We demonstrate that inhomogeneous sources of iodine oxides, i.e. "hot" spots with elevated iodine species emissions, could account for the aerosol production bursts observed in the coastal region near Mace Head, Ireland.

scholarly journals Laboratory studies of the homogeneous nucleation of iodine oxides

2003 ◽  
Vol 3 (5) ◽  
pp. 4943-4988 ◽  
Author(s):  
J. B. Burkholder ◽  
J. Curtius ◽  
A. R. Ravishankara ◽  
E. R. Lovejoy
Keyword(s):  
Boundary Layer ◽  
Homogeneous Nucleation ◽  
Marine Boundary Layer ◽  
Coastal Region ◽  
Field Measurements ◽  
Experimental Results ◽  
Model Parameters ◽  
Model Calculations ◽  
Aerosol Model ◽  
Iodine Oxides

Abstract. Laboratory experimental results of iodine oxide nucleation are presented. Nucleation was induced following UV photolysis of CF3I or CH2I2 in the presence of excess ozone. Measurements were performed in a 70 L Teflon reactor with new particles detected using an Ultrafine Condensation Particle Counter, UCPC. The experimental results are interpreted using a coupled chemical – aerosol model to derive model parameters assuming single component homogeneous nucleation of OIO. The aerosol model results have been applied in an atmospheric box-model to interpret the possible implications of iodine oxide nucleation in the marine boundary layer. The model calculations demonstrate that IO and OIO concentrations reported in recent field measurements (Allan et al., 2000, 2001) are not sufficient to account for significant aerosol production either in the coastal or open ocean marine boundary layer using the mechanism presented. We demonstrate that inhomogeneous sources of iodine oxides, i.e. "hot" spots with elevated iodine species emissions, could account for the aerosol production bursts observed in the coastal region near Mace Head, Ireland.

The side reactions in the esterification of phthalic anhydride with 2-ethylhexane-1-ol in the presence of organotitanates

1984 ◽  
Vol 49 (1) ◽  
pp. 253-266 ◽  
Author(s):  
Jan Novrocík ◽  
Marta Novrocíková ◽  
Jiří Norek ◽  
Ivan Koruna ◽  
Miroslav Ryska
Keyword(s):  
Titanium Dioxide ◽  
Quantitative Determination ◽  
Homogeneous Catalysis ◽  
Phthalic Anhydride ◽  
Spectral Methods ◽  
Side Reactions ◽  
Hydrated Titanium Dioxide ◽  
Ethylhexyl Phthalate ◽  
Hydrated Titanium

Using synthetic, chromatographic and spectral methods, we studied the side reactions accompanying the preparation of di-2-ethylhexyl phthalate from phthalic anhydride and 2-ethyl-hexane-1-ol in the presence of catalytic amounts of tetra-n-butyl titanate.The catalyst proper was titanium(IV) mono-2-ethylhexyl phthalate. The possibility of a simultaneous gas-chromatographic quantitative determination of mono-2-ethylhexyl phthalate, di-2-ethylhexyl phthalate, 2-ethylhexane-1-ol and tetra-n-butyl titanate, reported in the literature, has been refuted. In the esterification catalysed by hydrated titanium dioxide homogeneous catalysis by the formed organotitanate was dominating. The dissolving of hydrated titanium dioxide in the esterification of phthalic anhydride with 2-ethylhexane-1-ol was studied polarographically.

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