Publication Date:
2016-01-30
Description:
This work presents experimental data on the cloud condensation nuclei (CCN) activity of two-component mixtures containing surfactants. Nine binary systems were tested combining strong ionic (sodium dodecyl sulfate) and non-ionic surfactants (Zonyl FS-300 and Triton X-100) with non-surfactant compounds (glucose, ammonium sulfate, or sodium chloride). Control tests were performed for systems combining organic (glucose) and inorganic compounds (ammonium sulfate or sodium chloride). Results show that CCN activity deviates strongly relative to predictions made from measurements of bulk surface tension. Köhler theory accounting for surface tension reduction and surface partitioning underpredicts the CCN activity of particles containing Zonyl FS-300 and Triton X-100. Partitioning theory better describes data for Zonyl FS-300 and Triton X-100 when limiting surface adsorption to 1.5 monolayers of the growing drop. Deviations from predictions were observed. Likely explanations include solute-solute interactions and non-spherical particle shape. The findings presented here examine in detail the perturbation of CCN activity by surfactants and may offer insight into both the success and limitations of physical models describing CCN activity of surface active molecules.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
