Wen Zhang, 5th Year Ph.D. Candidate, a Postdoctoral Research Position

WEN ZHANG, University of California, Riverside

     Abstract Number: 260
     Working Group: Meet the Job Seekers

Abstract
I am Wen Zhang, a fifth-year Ph.D. candidate from the University of California, Riverside, and I plan to graduate in the Summer 2024. My research works on the potential interferences of popular analytical instrument of chemical ionization mass spectrometry (CIMS) to help eliminating the measurement misunderstanding of aerosol chemistry, as well as focuses on the heterogeneous kinetics and oxidation mechanism of various organic aerosol (OA) model systems which may reconcile the discrepancies between atmospheric observations and laboratory studies on organic aerosol aging.

In the first project (Zhang et al., Anal. Chem., 2021), we reported the occurrence of the secondary ion chemistry from interactions between a strong oxygen donor (such as O3 and peracids) and acidic OVOCs in the ion-molecule reaction (IMR) region of Iodide-adduct CIMS. The formation of such monomer and dimer clusters cause misinterpretations of molecular compositions and distributions of the gas-phase products and an overestimation of the elemental O/C ratio overall. My second project (Zhang et al., Environ. Sci. Technol., 2023) studied the heterogeneous OH-initialed OA aging using a continuous flow stirred tank reactor (CFSTR) to bring the laboratory [•OH] closer to the real atmosphere than typical flow tube reactors (FTR). We observed a chain propagation mechanism (i.e., autoxidation) in heterogeneous chemistry, causing OA oxidative aging of two to three orders of magnitude faster than previously reported. The following heterogeneous project will investigate on the oxidation kinetics and key oxidation products of •RO2 + •HO2 and •RO2 + NO bimolecular reactions. I also worked on another project of monoterpene-derived oxidation to characterize gas-phase •RO2 composition and particle-phase molecular-level SOA formation. In 2022, I wrote a review manuscript about recently developed mass spectrometry techniques for Mass Spectrometry Reviews.

After graduation, I plan to continue my study on atmospheric chemistry as a postdoctoral researcher for 1-2 years. I am looking forward to postdoctoral opportunities to continue my track in scientific research-related careers.