Nonlinear rheology of complex fluid–fluid interfaces

• Published in: Current opinion in colloid & interface science Vol. 19; no. 6; pp. 520 - 529
• Main Authors: Sagis, Leonard M.C., Fischer, Peter
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2014
• Subjects: adsorbed protein layers; adsorption layers; air-water-interface; amyloid fibrils; Colloids; Deformation; Dilatational properties; emulsions; extended irreversible thermodynamics; Foams; fourier-transform rheology; Interfaces; Interfacial shear; langmuir monolayers; liquid interfaces; Microstructure; Nonequilibrium thermodynamics; Nonlinear rheology; Nonlinearity; polymers; protein aggregates; Proteins; Rheology; surface shear rheology; thermodynamics; Interfaces; Nonlinear rheology; Interfacial shear; Dilatational properties
• ISSN: 1359-0294; 1879-0399
• DOI: 10.1016/j.cocis.2014.09.003

Fluid–fluid interfaces stabilized by proteins, protein aggregates, polymers, or colloidal particles, tend to have a complex microstructure. Their response to an applied deformation is often highly nonlinear, even at small deformation (rates). The nonlinearity of the response is a result of changes in the interfacial microstructure. Most of the studies on interfacial rheology of complex interfaces currently available in the scientific literature, focus on the linear response regime. Since multiphase systems such as emulsions or foam are routinely exposed to large and fast deformations, characterization of the nonlinear response of complex interfaces is highly relevant. In this paper we review the recent work on nonlinear rheology of complex interfaces, both in shear and dilatational deformations. We also discuss several methods currently available for analyzing nonlinear interfacial rheology data, and recent progress in modeling nonlinear interfacial rheology, using nonequilibrium thermodynamic frameworks. [Display omitted] •The response of complex interfaces to large deformations is often nonlinear.•This paper reviews the recent work on nonlinear responses in shear and dilatation.•In dilatational rheology strain amplitude variations are often not applied.•Lissajous curves and stress decomposition with special functions are useful tools.•Constitutive modeling of surface rheology is a field still in its infancy.