Inertial effects of adsorbed glycerol monostearate crystals on the shear rheology of water/canola oil interfaces

• Water/oil interface affected by glycerol monostearate (GMS) crystals in the oil phase is studied.
• The effects of aging time and GMS concentration are considered.
• Inertial effects give insights on possible mechanisms leading to interfacial structure build-up.

Glycerol monostearate (GMS) in canola oil dispersions (1.0%, 2.0%, and 3.0% w/w) were cooled down from 70 to 30 °C at a rate of 10.0 °C/min forming CD1.0, CD2.0, and CD3.0 crystal dispersions. Interfaces were prepared by pouring CDs over water, and were subjected to a constant shear stress. The creep compliance-time response of the interfaces depended on CD concentration, interfacial film aging time, and shear stress application time. Interfacial rheology experimental data were described by a nearly instantaneous response followed by an exponentially decaying function with two relaxation modes, the latter related to Kevin–Voigt elements connected serially involving inertial effects at relatively short times. The faster relaxation mode was related to the formation of a two-dimensional solid-like structure, while the slower relaxation mode was attributed slow crystal adsorption–desorption diffusional effects in the interface vicinity. The inertial effects had important influence on the interfacial rheology response.