Physical characterization of the aerosol of an electronic cigarette: impact of refill liquids

Abstract

Electronic cigarettes are used to evaporate a mixture of solvents, nicotine and flavors. Liquid particles can be generated under these conditions due to evaporation/condensation. The objective of this work is to measure the physical characteristics of the aerosol emission of an e-cigarette using different refill liquids. The aerosol particle number and size are determined with a Scanning Mobility Particle Sizer. Seven liquids are used: propylene glycol (PG), glycerol (VG), a mixture 1:1 of PG/VG, the mixture with 2% or 5% of a commercial flavor, the mixture with 1.2% of nicotine and the mixture with 1.2% of nicotine and 2% of flavor. Particle concentrations of the aerosol emitted from the electronic cigarette are 300–3000 times higher than that of the ambient air. Propylene glycol emits several times more than glycerol. The addition of a flavor or nicotine has little effect on the emission of the total number emitted. The count median diameter of the electronic cigarette particles is 200–400?nm, depending on the liquid used. Count median diameter of emitted particles is affected by the liquid used.