Effect of Decreased Temperature on the Evaporation of α-Pinene Secondary Organic Aerosol Particles

Interplay of volatility distribution and particle viscosity governs the gas-to-particle partitioning dynamics of atmospheric secondary organic aerosol (SOA) constituents. Temperature-induced shifts in both particle volatility distribution and viscosity can influence the evaporation behavior of atmospheric SOA particles. However, knowledge of the particle evaporation at low temperatures is still limited. Here, we combined the isothermal evaporation measurements and processes modelling to explore the evaporation of α-pinene ozonolysis (αpinO3) and photooxidation (αpinOH) SOA particles under a series of relative humidity (RH) at two different temperatures. Experimental results revealed that the particle evaporation was hindered at low temperature, in agreement with the temperature dependence of the effective saturation vapor concentration and the possible temperature impact on the particle viscosity. Both αpinO3 and αpinOH SOA particles showed similar evaporation rates at 80% RH when particles were in a liqu...