@article {27059,
	title = {Humidity-Dependent Phase State of Gasoline Vehicle Emission-Related Aerosols},
	journal = {Environmental Science and TechnologyEnvironmental Science and TechnologyEnvironmental Science \&amp; Technology},
	volume = {55},
	number = {2},
	year = {2021},
	note = {Export Date: 7 June 2021},
	pages = {832-841},
	type = {Article},
	abstract = {The phase states of primarily emitted and secondarily formed aerosols from gasoline vehicle exhausts were investigated by quantifying the particle rebound fraction (f). The rebound behaviors of gasoline vehicle emission-related aerosols varied with engines, fuel types, and photochemical aging time, showing distinguished differences from biogenic secondary organic aerosols. The nonliquid-to-liquid phase transition of primary aerosols emitted from port fuel injection (PFI) and gasoline direct injection (GDI) vehicles started at a relative humidity (RH) = 50 and 60\%, and liquefaction was accomplished at 60 and 70\%, respectively. The RH at which f declined to 0.5 decreased from 70 to 65\% for the PFI case with 92$\#$ fuel, corresponding to the photochemical aging time from 0.37 to 4.62 days. For the GDI case, such RH enhanced from 60 to 65\%. Our results can be used to imply the phase state of traffic-related aerosols and further understand their roles in urban atmospheric chemistry. Taking Beijing, China, as an example, traffic-related aerosols were mainly nonliquid during winter with the majority ambient RH below 50\%, whereas they were mostly liquid during the morning rush hour of summer, and traffic-related secondary aerosols fluctuated between nonliquid and liquid during the daytime and tended to be liquid at night with increased ambient RH. {\textcopyright} 2020 American Chemical Society.},
	keywords = {aerosol, aerosols, air pollutant, Air Pollutants, article, atmospheric chemistry, Atmospheric humidity, Beijing, China, Direct injection, exhaust gas, fuel, gasoline, Gasoline direct injection, Gasoline vehicle, humidity, liquefaction, Liquids, particulate matter, phase transition, photochemistry, Port fuel injections, Primary aerosols, Rebound behavior, secondary aerosols, secondary organic aerosol, secondary organic aerosols, summer, time, Traffic-related, vehicle emissions, Vehicles, winter},
	author = {Meng, X. and Wu, Z. and Guo, S. and Wang, H and Liu, K. and Zong, T. and Y. Liu and W. Zhang and Z. Zhang and S. Chen and Zeng, L. and Hallquist, M. and Shuai, S. and Hu, M.}
}
