es203066k_si_001.pdf (42.93 kB)
Ozone-Initiated Particle Formation, Particle Aging, and Precursors in a Laser Printer
journal contribution
posted on 2012-01-17, 00:00 authored by Hao Wang, Congrong He, Lidia Morawska, Peter McGarry, Graham JohnsonAn increasing number of researchers have hypothesized
that ozone
may be involved in the particle formation processes that occur during
printing, however no studies have investigated this further. In the
current study, this hypothesis was tested in a chamber study by adding
supplemental ozone to the chamber after a print job without measurable
ozone emissions. Subsequent particle number concentration and size
distribution measurements showed that new particles were formed minutes
after the addition of ozone. The results demonstrated that ozone did
react with printer-generated volatile organic compounds (VOCs) to
form secondary organic aerosols (SOAs). The hypothesis was further
confirmed by the observation of correlations among VOCs, ozone, and
particles concentrations during a print job with measurable ozone
emissions. The potential particle precursors were identified by a
number of furnace tests, which suggested that squalene and styrene
were the most likely SOA precursors with respect to ozone. Overall,
this study significantly improved scientific understanding of the
formation mechanisms of printer-generated particles, and highlighted
the possible SOA formation potential of unsaturated nonterpene organic
compounds by ozone-initiated reactions in the indoor environment.