Facile continuous process for gas phase halogen exchange over supported alkyl phosphonium salts

Chloride–bromide halogen exchange was realized when a mixture of an alkyl chloride and an alkyl bromide were reacted over a supported molten alkyl phosphonium catalyst.

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Stereochemistry of the decay-induced gas-phase halogen exchange in diastereomeric 2,3-dichlorobutanes

The Journal of Physical Chemistry ◽

10.1021/j100604a001 ◽

1974 ◽

Vol 78 (11) ◽

pp. 1043-1048 ◽

Cited By ~ 10

Author(s):

Samuel H. Daniel ◽

Hans J. Ache ◽

Gerhard Stoecklin

Keyword(s):

Gas Phase ◽

Halogen Exchange

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Decontamination of N95 and surgical masks using a treatment based on a continuous gas phase-Advanced Oxidation Process

PLoS ONE ◽

10.1371/journal.pone.0248487 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0248487

Author(s):

Mahdiyeh Hasani ◽

Tracey Campbell ◽

Fan Wu ◽

Keith Warriner

Keyword(s):

Hydrogen Peroxide ◽

Gas Phase ◽

Hydroxyl Radicals ◽

Advanced Oxidation Process ◽

Oxidation Process ◽

Continuous Process ◽

Oxidative Polymerization ◽

Advanced Oxidation ◽

Surgical Masks ◽

Uv C

A gas-phase Advanced Oxidation Process (gAOP) was evaluated for decontaminating N95 and surgical masks. The continuous process was based on the generation of hydroxyl-radicals via the UV-C (254 nm) photo-degradation of hydrogen peroxide and ozone. The decontamination efficacy of the gAOP was dependent on the orientation of the N95 mask passing through the gAOP unit with those positioned horizontally enabling greater exposure to hydroxyl-radicals compared to when arranged vertically. The lethality of gAOP was independent of the applied hydrogen peroxide concentration (2–6% v/v) but was significantly (P<0.05) higher when H2O2 was introduced into the unit at 40 ml/min compared to 20 ml/min. A suitable treatment for N95 masks was identified as 3% v/v hydrogen peroxide delivered into the gAOP reactor at 40 ml/min with continuous introduction of ozone gas and a UV-C dose of 113 mJ/cm2 (30 s processing time). The treatment supported >6 log CFU decrease in Geobacillus stearothermophilus endospores, > 8 log reduction of human coronavirus 229E, and no detection of Escherichia coli K12 on the interior and exterior of masks. There was no negative effect on the N95 mask fitting or particulate efficacy after 20 passes through the gAOP system. No visual changes or hydrogen peroxide residues were detected (<1 ppm) in gAOP treated masks. The optimized gAOP treatment could also support >6 log CFU reduction of endospores inoculated on the interior or exterior of surgical masks. G. stearothermophilus Apex spore strips could be applied as a biological indicator to verify the performance of gAOP treatment. Also, a chemical indicator based on the oxidative polymerization of pyrrole was found suitable for reporting the generation of hydroxyl-radicals. In conclusion, gAOP is a verifiable treatment that can be applied to decontaminate N95 and surgical masks without any negative effects on functionality.

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Organocatalyzed controlled radical polymerization with alkyl bromide initiator via in situ halogen exchange under thermal condition

Polymer ◽

10.1016/j.polymer.2020.122201 ◽

2020 ◽

Vol 189 ◽

pp. 122201 ◽

Cited By ~ 1

Author(s):

Bogeng Guo ◽

Linxi Hou ◽

Yan Li ◽

Longqiang Xiao

Keyword(s):

Radical Polymerization ◽

Thermal Condition ◽

Controlled Radical Polymerization ◽

Alkyl Bromide ◽

Halogen Exchange

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Continuous process of the vacuum ultraviolet- (VUV-) photochemical oxidation of thiophene in the gas phase

Photochemical & Photobiological Sciences ◽

10.1039/c4pp00476k ◽

2015 ◽

Vol 14 (5) ◽

pp. 1013-1024 ◽

Cited By ~ 1

Author(s):

Haingo L. Andriampanarivo ◽

Martin Köhler ◽

Juan López Gejo ◽

Thomas Betzwieser ◽

Benny C. Y. Poon ◽

...

Keyword(s):

Gas Phase ◽

Kinetic Data ◽

Oxidation Reaction ◽

Vacuum Ultraviolet ◽

Continuous Process ◽

Oxidative Degradation ◽

Photochemical Oxidation ◽

Reaction Pathways ◽

Intermediate Products

Based on kinetic data and intermediate products of oxidation, reaction pathways of the oxidative degradation of gaseous thiophene are discussed.

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Numerical and Experimental Study on the Cavitating Flow Characteristics of Pressurized Liquid Nitrogen in a Horizontal Rectangular Nozzle

Journal of Pressure Vessel Technology ◽

10.1115/1.1928916 ◽

2004 ◽

Vol 127 (4) ◽

pp. 515-524 ◽

Cited By ~ 7

Author(s):

Jun Ishimoto ◽

Masahiro Onishi ◽

Kenjiro Kamijo

Keyword(s):

Experimental Study ◽

Gas Phase ◽

Liquid Nitrogen ◽

Cooling System ◽

Continuous Process ◽

Cavity Growth ◽

Flow Characteristics ◽

Cavitating Flow ◽

Rectangular Nozzle ◽

Thermodynamic Effect

The thermodynamic effect on cryogenic cavitating flow characteristics of pressurized liquid nitrogen in a horizontal rectangular nozzle is precisely investigated by numerical analysis based on an unsteady thermal nonequilibrium two-fluid model and by flow visualization measurement. According to the numerical and experimental study, the sufficiently useful results are proposed to realize the further development and high performance of a type of cryogenic two-phase cooling system. It is numerically and experimentally found that the inception of cryogenic cavitation occurs and the cavity grows in the vicinity of the wall surface of the inlet throat section. It is also found that the continuous process and behavior of cavitation inception, cloud cavity growth, and gas phase diffusion behavior with time in pressurized liquid nitrogen are dominated not only by several additional forces in the gas-phase momentum equation, but also by the thermodynamic effect that acts on the cavitation bubbles due to the inherent properties of cryogenic fluid. Especially under conditions of the same temperature and same aspect ratio of the cloud cavity, similar generating behavior of cavitation can be often found in the high Reynolds number region in spite of large cavitation number.

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SN2 and SN2′ reaction dynamics of cyclopropenyl chloride with halide ion A direct ab initio molecular dynamics (MD) study

Canadian Journal of Chemistry ◽

10.1139/v05-176 ◽

2005 ◽

Vol 83 (9) ◽

pp. 1597-1605 ◽

Cited By ~ 1

Author(s):

Hiroto Tachikawa

Keyword(s):

Molecular Dynamics ◽

Reaction Mechanism ◽

Ab Initio ◽

Gas Phase ◽

Reaction Channel ◽

Ab Initio Molecular Dynamics ◽

Methylene Carbon ◽

Methylene Carbon Atom ◽

Halogen Exchange ◽

Collision Angle

Direct ab initio molecular dynamics (MD) calculations have been carried out for the reaction of cyclopropenyl chloride with halide ion (F) (F + (CH)3Cl → F(CH)3 + Cl) in gas phase. Both SN2 and SN2′ channels were found as product channels. These channels are strongly dependent on the collision angle of F to the target (CH)3Cl molecule. The collision at one of the carbon atoms of the C=C double bond leads to the SN2′ reaction channel; whereas the collision at the methylene carbon atom leads to the SN2 reaction channel. The reactions proceed via a direct mechanism without long-lived complexes. The reaction mechanism is discussed on the basis of the theoretical results.Key words: SN2 reaction, direct ab initio molecular dynamics, halogen exchange, reaction mechanism.

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