Rheology of particulate rafts, films, and foams

Abstract

Liquid foam exhibits remarkable rheological behavior although it is made with simple fluids: it behaves like a solid at low shear stress but flows like a liquid above a critical shear stress. Such properties, that have been proved to be useful for many applications, are even enhanced by adding solid particles. Depending on their hydrophobicity and their size, the particles can have different geometrical configurations at the mesoscopic scale, i.e. at the air-liquid interfaces, in the films or the interstices between the bubbles. In this review, we present rheological studies performed on granular rafts and films, on spherical armored interfaces, on gas marbles and on aqueous foams laden with hydrophilic grains.

In vitro antioxidant and antidiabetic activity of essential oils encapsulated in gelatin‐pectin particles against sugar, lipid and protein oxidation and amylase and glucosidase activity

“…The increase in the shear stress may be related to a negative charge and the small sizes of the particles and to the increased interfacial surface and finally causing a rise in the friction force between particles. By the increase in the shear rate, the contact between particles will be increased and the result is the increase in shear stress (Pitois & Rouyer, 2019).…”

Editorial overview: Rheology of soft materials: Recent progresses

“…Both the Rouyer team [5] and Urayama laboratory [8] found experimentally yielding behaviour of foams and microgels, which is the last topic of this special edition. While viscoplastic fluids are synonymously called yield stress fluids characterised by having a yield stress, there is less consensus beyond that, as the concept of a yield stress has been continually debated for the past three to four decades.…”

“…Again, particles were demonstrated extensively as a crucial component in stabilizing foams with the Pickering rule. Pitois and Rouyer [5] presented rheological studies performed on granular rafts and films, spherical armoured interfaces, gas marbles, and aqueous foams laden with hydrophilic grains. They started with interfacial rheological basics for single armoured fluid interfaces as planar rafts and drops-bubbles.…”

Yield stress of aerated cement paste

“…We will recall here the main literature results. To get a more complete understanding of this complex issue, one can read the recents reviews from Thijssen and Vermant [33], Maestro [34] and Pitois and Rouyer [35].…”