Heteroaggregation of water-in-oil droplets: the effects of relative internal solute concentrations and size

Abstract

An attractive interaction between disparately-sized aqueous droplets dispersed in oil has been observed: small salty water droplets tend to stick to and withdraw water from larger droplets that have the same or lower salinity (if <100 mM). The attractive interaction, however, is not observed if small droplets are mixed with droplets that are both larger and saltier. In the latter case, provided there is insufficient salt present in the small droplets to prevent it, the larger droplets grow by a compositional ripening mechanism.