Document Type

Article

Publication Date

10-2016

Subject: LCSH

Polycyclic aromatic hydrocarbons, Soot, Aerosols

Disciplines

Chemical Engineering | Chemistry

Abstract

We investigated the effect of thin polycyclic aromatic hydrocarbon (PAH) coatings on the structure of soot aggregates. Soot aerosol from an inverted diffusion burner was size classified, thermally denuded, coated with six different PAHs, and then characterized using scanning electron microscopy, light scattering, and mass-mobility measurements. Contrary to our expectation, significant restructuring was observed in the presence of subnanometer layers of pyrene, fluoranthene, and phenanthrene. These PAHs remained in subcooled liquid state in thin films, whereby the liquid layer acted as a lubricant, reducing the force required to initiate the restructuring. Thin layers of PAH of higher melting temperatures (perylene, anthracene, and triphenylene) presumably remained solid because these chemicals induced lesser structural changes. Our results suggest that some of the intrinsic PAH generated during incomplete combustion may induce significant restructuring of soot aggregates, even when present in small quantities, altering the properties and atmospheric impacts of combustion aerosols.

Comments

(C) American Geophysical Union. All rights reserved. Free access article originally published at https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/2016GL070877

Posted on behalf of author in compliance with publisher's policy. For information on the publisher's policy for reuse of this article, please refer to the publisher's site: https://publications.agu.org/author-resource-center/usage-permissions/#repository

DOI

10.1002/2016GL070877

Publisher Citation

Chen, C., X. Fan, T. Shaltout, C. Qiu, Y. Ma, A. Goldman, and A. F. Khalizov (2016), An unexpected restructuring of combustion soot aggregates by subnanometer coatings of polycyclic aromatic hydrocarbons, Geophys. Res. Lett. 43, 11,080–11,088, doi:10.1002/2016GL070877.

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