Heterogeneous uptake of octamethylcyclotetrasiloxane (D 4) and decamethylcyclopentasiloxane (D 5) onto mineral dust aerosol under variable RH conditions

Juan G Navea; Shihe Xu; Charles O Stanier; Mark A Young; Vicki H Grassian

doi:10.1016/j.atmosenv.2009.05.012

Back

Heterogeneous uptake of octamethylcyclotetrasiloxane (D 4) and decamethylcyclopentasiloxane (D 5) onto mineral dust aerosol under variable RH conditions

Journal article

Peer reviewed

Heterogeneous uptake of octamethylcyclotetrasiloxane (D 4) and decamethylcyclopentasiloxane (D 5) onto mineral dust aerosol under variable RH conditions

Juan G Navea, Shihe Xu, Charles O Stanier, Mark A Young and Vicki H Grassian

Atmospheric environment (1994), Vol.43(26), pp.4060-4069

2009

DOI: 10.1016/j.atmosenv.2009.05.012

View Online

Abstract

We have carried out kinetic studies to characterize the heterogeneous decay of octamethylcyclotetrasiloxane (D 4) and decamethylcyclopentasiloxane (D 5) in the presence of representative mineral dust aerosol in order to obtain a better understanding of the atmospheric fate of these siloxanes. The heterogeneous chemistry of D 4 and D 5 with various mineral dusts was studied in an environmental aerosol reaction chamber using FTIR absorption spectroscopy to monitor the reaction. The apparent heterogeneous uptake coefficient, γ app, for D 4 and D 5 with various mineral dusts was measured under dry conditions and as a function of relative humidity (RH). In addition, the effect of initial D 4 and D 5 concentration on the rate and yield of the reaction was examined. The uptake coefficient, γ app, for D 4 and D 5 was similar for the most reactive aerosols tested, with kaolinite ≈hematite > silica. Limited uptake onto carbon black and calcite surfaces was observed for either siloxane. Reaction with hematite and kaolinite resulted in multilayer coverages, suggesting extensive polymerization of D 4 and D 5 on the aerosol surface.

Atmospheric chemistry

Siloxanes

Surface chemistry

D 5

D 4

Environmental fate

Heterogeneous chemistry

Details

Title: Subtitle: Heterogeneous uptake of octamethylcyclotetrasiloxane (D 4) and decamethylcyclopentasiloxane (D 5) onto mineral dust aerosol under variable RH conditions
Creators: Juan G Navea - Department of Chemistry, The University of Iowa, Iowa City, IA 52246, USA
Shihe Xu - Health and Environmental Sciences, Dow Corning Corporation, Midland, MI 48686-0994, USA
Charles O Stanier - Departments of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USA
Mark A Young - Department of Chemistry, The University of Iowa, Iowa City, IA 52246, USA
Vicki H Grassian - Department of Chemistry, The University of Iowa, Iowa City, IA 52246, USA
Resource Type: Journal article
Publication Details: Atmospheric environment (1994), Vol.43(26), pp.4060-4069
DOI: 10.1016/j.atmosenv.2009.05.012
ISSN: 1352-2310
eISSN: 1873-2844
Publisher: Elsevier Ltd
Language: English
Date published: 2009
Academic Unit: Occupational and Environmental Health; Chemistry; Chemical and Biochemical Engineering
Record Identifier: 9984003996402771

Metrics

12 Record Views

22 Times Cited - Web of Science