The role of total pressure in gas-phase nucleation: A diffusion effect

2003 ◽  
Vol 118 (2) ◽  
pp. 736-745 ◽  
Author(s):  
S.-M. Suh ◽  
S. L. Girshick ◽  
M. R. Zachariah
Keyword(s):  
Gas Phase ◽  
Total Pressure ◽  
Diffusion Effect ◽  
Phase Nucleation

scholarly journals The role of radiolysis in the modelling of C2H4O2 isomers and dimethyl ether in cold dark clouds

2020 ◽  
Vol 500 (3) ◽  
pp. 3414-3424
Author(s):  
Alec Paulive ◽  
Christopher N Shingledecker ◽  
Eric Herbst
Keyword(s):  
Gas Phase ◽  
Dimethyl Ether ◽  
Recent Observation ◽  
Cosmic Ray ◽  
Thermal Method ◽  
Dark Clouds ◽  
Ice Surface ◽  
Dust Grain ◽  
Complex Organic

ABSTRACT Complex organic molecules (COMs) have been detected in a variety of interstellar sources. The abundances of these COMs in warming sources can be explained by syntheses linked to increasing temperatures and densities, allowing quasi-thermal chemical reactions to occur rapidly enough to produce observable amounts of COMs, both in the gas phase, and upon dust grain ice mantles. The COMs produced on grains then become gaseous as the temperature increases sufficiently to allow their thermal desorption. The recent observation of gaseous COMs in cold sources has not been fully explained by these gas-phase and dust grain production routes. Radiolysis chemistry is a possible non-thermal method of producing COMs in cold dark clouds. This new method greatly increases the modelled abundance of selected COMs upon the ice surface and within the ice mantle due to excitation and ionization events from cosmic ray bombardment. We examine the effect of radiolysis on three C2H4O2 isomers – methyl formate (HCOOCH3), glycolaldehyde (HCOCH2OH), and acetic acid (CH3COOH) – and a chemically similar molecule, dimethyl ether (CH3OCH3), in cold dark clouds. We then compare our modelled gaseous abundances with observed abundances in TMC-1, L1689B, and B1-b.

scholarly journals How volatile components catalyze vapor nucleation

2021 ◽  
Vol 7 (3) ◽  
pp. eabd9954 ◽  
Author(s):  
Chenxi Li ◽  
Jan Krohn ◽  
Martina Lippe ◽  
Ruth Signorell
Keyword(s):  
Gas Phase ◽  
Molecular Level ◽  
Volatile Components ◽  
Transient Species ◽  
Gaseous Species ◽  
Alternative Pathways ◽  
Nucleation Mechanisms ◽  
Designed Experiment ◽  
Phase Nucleation ◽  
Vapor Nucleation

Gas phase nucleation is a ubiquitous phenomenon in planetary atmospheres and technical processes, yet our understanding of it is far from complete. In particular, the enhancement of nucleation by the addition of a more volatile, weakly interacting gaseous species to a nucleating vapor has escaped molecular-level experimental investigation. Here, we use a specially designed experiment to directly measure the chemical composition and the concentration of nucleating clusters in various binary CO2-containing vapors. Our analysis suggests that CO2 essentially catalyzes nucleation of the low vapor pressure component through the formation of transient, hetero-molecular clusters and thus provides alternative pathways for nucleation to proceed more efficiently. This work opens up new avenues for the quantitative assessment of nucleation mechanisms involving transient species in multicomponent vapors.

Role of solid- and gas-phase interactions in the coaction of the oxides in MnO2 + PbO and MnO2 + V2O5 compositions activating the thermal oxidation of GaAs

2007 ◽  
Vol 52 (10) ◽  
pp. 1498-1502 ◽  
Author(s):  
V. F. Kostryukov ◽  
V. R. Pshestanchik ◽  
I. A. Donkareva ◽  
B. L. Agapov ◽  
S. I. Lopatin ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Gas Phase

Formation of OH radicals in the gas phase ozonolysis of alkenes: the unexpected role of carbonyl oxides

1996 ◽  
Vol 252 (3-4) ◽  
pp. 221-229 ◽  
Author(s):  
Roland Gutbrod ◽  
Ralph N. Schindler ◽  
Elfi Kraka ◽  
Dieter Cremer
Keyword(s):  
Gas Phase ◽  
Oh Radicals ◽  
Carbonyl Oxides

scholarly journals Efficient utilization of renewable feedstocks: the role of catalysis and process design

2017 ◽  
Vol 376 (2110) ◽  
pp. 20170064 ◽  
Author(s):  
Regina Palkovits ◽  
Irina Delidovich
Keyword(s):  
Elevated Temperature ◽  
Gas Phase ◽  
Process Design ◽  
Circular Economy ◽  
Paradigm Shift ◽  
Efficient Utilization ◽  
Polar Solvents ◽  
Platform Chemicals ◽  
Renewable Feedstocks

Renewable carbon feedstocks such as biomass and CO 2 present an important element of future circular economy. Especially biomass as highly functionalized feedstock provides manifold opportunities for the transformation into attractive platform chemicals. However, this change of the resources requires a paradigm shift in refinery design. Fossil feedstocks are processed in gas phase at elevated temperature. In contrast, biorefineries are based on processes in polar solvents at moderate conditions to selectively deoxygenate the polar, often thermally instable and high-boiling molecules. Here, challenges of catalytic deoxygenation, novel strategies for separation and opportunities provided at the interface to biotechnology are discussed in form of showcases. This article is part of a discussion meeting issue ‘Providing sustainable catalytic solutions for a rapidly changing world’.

Sign in / Sign up

Export Citation Format

Share Document