Cationic polymerization of gaseous isoprene on mildly acidic water

Agustin J. Colussi; Shinichi Enami; Himanshu Mishra; Michael R. Hoffmann

Cationic polymerization of gaseous isoprene on mildly acidic water

Agustin J. Colussi^*, Shinichi Enami, Himanshu Mishra, Michael R. Hoffmann

^*Corresponding author for this work

Research output: Contribution to journal › Conference article › peer-review

Abstract

The conversion of gaseous isoprene (Iso _g) into secondary organic aerosol is a major tropospheric process that affects air quality and the Earth's radiative balance. Herein we report that Iso _g is protonated upon collision with mildly acidic water (1 < pH < 4) thereby initiating the formation of oligomers in the condensed phase. The identical dependences of IsoH ⁺, (Iso) ₂H ⁺ and (Iso) ³H ⁺ on pH, and the linear and quadratic dependences of (Iso) ₂H ⁺/IsoH ⁺ and (Iso) ₃H ⁺/IsoH ⁺ on Iso _g, respectively, imply that the oligomerization process is propagated by reactions of Iso _g with interfacial cationic carriers (Iso) _iH ⁺. Decreasing IsoH ⁺/IsoD ⁺ > (Iso) ₂H ⁺/(Iso) ₂D ⁺ > (Iso) ₃H ⁺/(Iso) ₃D ⁺ ratios in solvent deuteration experiments are consistent with direct and inverse kinetic isotope effect for initiation (protonation) and propagation steps, respectively. These experiments show that atmospheric isoprene, and possibly other biogenic unsaturate gases, will readily polymerize on weakly acidic aerosols, fogs and clouds.

Original language	English (US)
Journal	ACS National Meeting Book of Abstracts
State	Published - 2011
Externally published	Yes
Event	242nd ACS National Meeting and Exposition - Denver, CO, United States Duration: Aug 28 2011 → Sep 1 2011

ASJC Scopus subject areas

General Chemistry
General Chemical Engineering

Cite this

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title = "Cationic polymerization of gaseous isoprene on mildly acidic water",

abstract = "The conversion of gaseous isoprene (Iso g) into secondary organic aerosol is a major tropospheric process that affects air quality and the Earth's radiative balance. Herein we report that Iso g is protonated upon collision with mildly acidic water (1 < pH < 4) thereby initiating the formation of oligomers in the condensed phase. The identical dependences of IsoH +, (Iso) 2H + and (Iso) 3H + on pH, and the linear and quadratic dependences of (Iso) 2H +/IsoH + and (Iso) 3H +/IsoH + on Iso g, respectively, imply that the oligomerization process is propagated by reactions of Iso g with interfacial cationic carriers (Iso) iH +. Decreasing IsoH +/IsoD + > (Iso) 2H +/(Iso) 2D + > (Iso) 3H +/(Iso) 3D + ratios in solvent deuteration experiments are consistent with direct and inverse kinetic isotope effect for initiation (protonation) and propagation steps, respectively. These experiments show that atmospheric isoprene, and possibly other biogenic unsaturate gases, will readily polymerize on weakly acidic aerosols, fogs and clouds.",

author = "Colussi, {Agustin J.} and Shinichi Enami and Himanshu Mishra and Hoffmann, {Michael R.}",

year = "2011",

language = "English (US)",

journal = "ACS National Meeting Book of Abstracts",

issn = "0065-7727",

publisher = "AMER CHEMICAL SOC",

note = "242nd ACS National Meeting and Exposition ; Conference date: 28-08-2011 Through 01-09-2011",

}

TY - JOUR

T1 - Cationic polymerization of gaseous isoprene on mildly acidic water

AU - Colussi, Agustin J.

AU - Enami, Shinichi

AU - Mishra, Himanshu

AU - Hoffmann, Michael R.

PY - 2011

Y1 - 2011

N2 - The conversion of gaseous isoprene (Iso g) into secondary organic aerosol is a major tropospheric process that affects air quality and the Earth's radiative balance. Herein we report that Iso g is protonated upon collision with mildly acidic water (1 < pH < 4) thereby initiating the formation of oligomers in the condensed phase. The identical dependences of IsoH +, (Iso) 2H + and (Iso) 3H + on pH, and the linear and quadratic dependences of (Iso) 2H +/IsoH + and (Iso) 3H +/IsoH + on Iso g, respectively, imply that the oligomerization process is propagated by reactions of Iso g with interfacial cationic carriers (Iso) iH +. Decreasing IsoH +/IsoD + > (Iso) 2H +/(Iso) 2D + > (Iso) 3H +/(Iso) 3D + ratios in solvent deuteration experiments are consistent with direct and inverse kinetic isotope effect for initiation (protonation) and propagation steps, respectively. These experiments show that atmospheric isoprene, and possibly other biogenic unsaturate gases, will readily polymerize on weakly acidic aerosols, fogs and clouds.

AB - The conversion of gaseous isoprene (Iso g) into secondary organic aerosol is a major tropospheric process that affects air quality and the Earth's radiative balance. Herein we report that Iso g is protonated upon collision with mildly acidic water (1 < pH < 4) thereby initiating the formation of oligomers in the condensed phase. The identical dependences of IsoH +, (Iso) 2H + and (Iso) 3H + on pH, and the linear and quadratic dependences of (Iso) 2H +/IsoH + and (Iso) 3H +/IsoH + on Iso g, respectively, imply that the oligomerization process is propagated by reactions of Iso g with interfacial cationic carriers (Iso) iH +. Decreasing IsoH +/IsoD + > (Iso) 2H +/(Iso) 2D + > (Iso) 3H +/(Iso) 3D + ratios in solvent deuteration experiments are consistent with direct and inverse kinetic isotope effect for initiation (protonation) and propagation steps, respectively. These experiments show that atmospheric isoprene, and possibly other biogenic unsaturate gases, will readily polymerize on weakly acidic aerosols, fogs and clouds.

UR - http://www.scopus.com/inward/record.url?scp=84861091783&partnerID=8YFLogxK

M3 - Conference article

AN - SCOPUS:84861091783

SN - 0065-7727

JO - ACS National Meeting Book of Abstracts

JF - ACS National Meeting Book of Abstracts

T2 - 242nd ACS National Meeting and Exposition

Y2 - 28 August 2011 through 1 September 2011

ER -

Cationic polymerization of gaseous isoprene on mildly acidic water

Abstract

ASJC Scopus subject areas

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