Interfacial properties: interfacial tension, interfacial rheology


Interfacial rheology is the study of the relationship between stress and strain/strain rate at liquid-liquid or liquid-gas interfaces. Interfacial rheological properties play a central role in determining the stability of emulsions, foams and biofilms found in the food, coatings, paints, cosmetics, petroleum, pharmaceutical and biomedical industries.


GReo studies the formation and stability mechanisms of oil-water emulsions, the stability of hydrates, the influence of asphaltene molecules on the oil-water interface and the efficiency of commercial demulsifiers. In addition, we have a line of research focused on the study and prototyping of accessories for tensiometers and rheometers in order to measure tension and interfacial rheology with greater reliability.

We have several pieces of equipment to measure interfacial viscosity in shear and viscoelastic properties under different temperatures, namely TA Instruments’ DHR-3 and ARES-G2 rotational rheometers with Double Wall Ring and Du Noüy ring geometries and Anton’s MCR301 and MCR501 rheometers Paar with bicone geometry. Such rheometers can be associated with a Langmuir vessel to determine the effect of surface pressure on interfacial rheological properties related to steady and oscillatory shear flows. In addition, we are able to measure surface and interfacial tension at ambient pressure with the tensiometers K100C from Kruss GMBH and TE 1C from Lauda and under high pressures with the traker H tensiometer from Teclis Instruments.

 

Infrastructure: rotational rheometer; Langmuir vat; tensiometers; Turbiscan stability analyzer; 3d printer.