AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Atomistic Study of Synergism Among Surfactants at the Air-Water Interface
Gözde Ergin, Mária Darvas, SATOSHI TAKAHAMA, EPFL
Abstract Number: 776 Working Group: Aerosols, Clouds, and Climate
Abstract Recent work has shown that atmospheric aerosols can have significantly lower surface tensions laboratory aerosols (Baduel et al., 2012). Understanding the origins of this difference is essential for advancing our capability to model the effect of on cloud droplet formation. One hypothesis is that there are a class of understudied molecules in atmospheric particles that lower the surface tension significantly, such as biosurfactants (Eckström et al., 2010). A second hypothesis is that non-additive interactions among certain molecules lower surface tensions lower below that predicted from their individual contributions. For instance, such interactions can exist among ionic surfactants that have been found in atmospheric aerosols (Gérard et al., 2016).
In this work, we explore the atomistic interactions among surfactants and water which lead to synergistic behavior. We first present detailed analysis of pure and mixed systems containing sodium dodecyl sulfate (SDS) and lauryl betaine, which is a system known to exhibit strong synergism. For contrast, we present analysis for a non-synergistic system of SDS and cocoamidopropyl betaine, where the latter molecule varies from lauryl betaine by an amide group in the skeletal tail. We discuss possible implications of mixing surfactants on the surface tension in atmospheric aerosols.
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