Investigating Influence of Particle Size on Volatility of Aerosols

SUNANDAN MAHANT, Markus Petters, University of California, Riverside

     Abstract Number: 508
     Working Group: Aerosol Physics

Abstract
Existing saturation vapor pressure estimation methods need validation through experimental data. Particle evaporation rates depend on the compound saturation vapor pressure, the tension of the particle/air interface, and the accommodation coefficient. Here we used a tandem differential mobility analyzer to characterize evaporation rates as a function of temperature and particle size for initial mobility diameters between 10 nm and 500 nm. The experiments are motivated by the need to probe the potential influence of phase transitions on interfacial tension and vapor pressure. Experimental results were found to be in good agreement with a kinetic evaporation model, initialized with saturation vapor pressure at a standard state, enthalpy of vaporization, a single value of the accommodation coefficient, and a single value of particle/air interfacial tension. Thus the results suggest that the existing estimation method works well even for particles where the Kelvin effect significantly enhances evaporation rates.