ИСТИНА

Microgels are macromolecular networks which size usually varies from tens of nanometers to several microns. They possess both colloidal and polymeric properties: on the one hand, microgels can keep their shape in solutions like hard colloidal particles with main difference that solvent can occupy the most part of microgel’s volume; on the other hand, microgels can change their shape due to swell or collapse of their subchains which is caused by the alteration of external conditions (change of temperature, pH, solution ionic strength, etc.). The latter peculiarity of such polymer objects could be applied in emulsion stabilization. Recently [1], it has been shown that microgels can serve as the soft alternative to the solid emulsifiers. While being located near the boundary of two immiscible liquids the polymer networks quickly adsorb onto the interface and spread on it obtaining the “fried egg” conformations and thus covering a larger area than the solid particles. Therefore, one needs sufficiently less amount of microgels to create a stable emulsion. Such effect can be extended to the case when the fraction of one of the liquid phases is very low, i.e. with no observable phase separation on macroscale. In this situation it is expected that microgels can act as the molecular “scavengers” – they can absorb the minor phase while preserving their colloidal stability. This phenomenon could be used in water purification after the catalytic reactions or for the petroleum refinery after the extraction of resource from the oil field. The actual problem here is to find the conditions when microgels can rather act like scavengers than surfactants. In this research, using dissipative particle dynamics (DPD) simulations we studied the microgels absorption behavior in multicomponent systems of incompatible liquids when the fraction of one liquid is much less than the fraction of another liquid. The effects of the components concentration, interactions and microgel structure on the absorbtion behavior were studied. Also, we considered the microgels aggregation at different concentrations of minor liquid.