University College Cork

Born in Cork, Trevor graduated with a B.Sc. Chemistry degree in University College Cork in 2004. He carried out his Ph.D. research under the supervision of Prof. John Wenger at The Centre for Research into Atmospheric Chemistry and at The Environmental Research Institute in UCC. Trevor's research focused on the Atmospheric Simulation Chamber Studies of the Ozonolysis of Green Leaf Volatiles. Trevor completed his Ph.D. in 2010.

Trevor was appointed Technical Officer for the School of Chemistry in 2011 and became Senior Technical Officer in 2016. He is responsible for undergraduate Physical Chemistry practicals and other activities in research and public engagement.

Trevor is very active in outreach activities for the School of Chemistry. He was coordinator of the highly successful RSC/SFI funded scheme 'Spectroscopy in a Suitcase' from 2014-2020 and is heavily involved in the running of the Salters Festival of Chemistry, Open Days and other events. Trevor is sole administrator of the School of Chemistry website, and five social media channels, using modern platforms and methods to communicate positive news on teaching, student awards and research achievements to a far-reaching online audience. In addition, Trevor is editor of the School of Chemistry newsletter.

Trevor's work has been recognised in the form of prestigious awards and nominations internally from the College of SEFS (2020) and UCC (2018), and externally from the Royal Society of Chemistry (2018), Cork City Council (2021) and Times Higher Education (2021).

Thesis title: Atmospheric Simulation Chamber Studies of the Ozonolysis of Green Leaf Volatiles

Supervisor: Prof. John Wenger

Abstract: Green leaf volatiles (GLVs) are a family of oxygenated hydrocarbons produced from the biochemical conversion of linoleic and linolenic acid within plants. The compounds (Z)-3-hexenyl acetate, (Z)-3-hexenol and (Z)-3-hexenal form an important subset of GLVs that are emitted into the atmosphere in large quantities. In order to understand their impact on the atmosphere, information on their atmospheric degradation processes is required. A series of laboratory studies has been performed on the gas-phase ozonolysis of (Z)-3-hexenyl acetate, (Z)-3-hexenol, (Z)-3-hexenal and the structurally related compound, (Z)-3-hexene. Rate coefficients for the reactions were measured at 295 ± 2 K and atmospheric pressure.

The kinetic data allows conclusions to be made on the effect of various functional groups on the reactivity of the GLVs towards ozone. Yields for the primary carbonyl, propanal, and the OH radical were also measured and the contribution of each Criegee intermediate towards the overall OH radical yield was determined. The molecular composition of secondary organic aerosol (SOA) produced from the ozonolysis of the GLVs was investigated by off-line analysis of filter samples. Many low molecular weight products were identified using two dimensional gas chromatography time-of-flight mass spectrometry, while liquid chromatography mass spectrometry proved effective in characterization of short and longer chain oligomers.

The extent of oligomer formation showed a large dependence on the functional group within the GLV molecule; although dimer formation was observed for all of the compounds, higher order oligomers were only produced to a significant extent in the SOA from (Z)-3-hexenol. This is attributed to the high reactivity of its first generation oxidation product, 3-hydroxypropanal, which can hydrate and readily undergo further reactions in the particle phase. The yields of SOA produced from the ozonolysis of (Z)-3-hexenyl acetate and (Z)-3-hexenol were determined under a variety of reaction conditions.

The results indicate that the SOA yield increases for higher starting concentrations of GLV, lower relative humidity and in the presence of seed aerosol. SOA formation yields from (Z)-3-hexenol are higher than those from (Z)-3-hexenyl acetate. The results suggest that GLVs are a potentially important global source of SOA.