Janus Particles at Fluid Interfaces: Stability and Interfacial Rheology

Abstract

The use of the Janus motif in colloidal particles, i.e., anisotropic surface properties on opposite faces, has gained significant attention in the bottom-up assembly of novel functional structures, design of active nanomotors, biological sensing and imaging, and polymer blend compatibilization. This review is focused on the behavior of Janus particles in interfacial systems, such as particle-stabilized (i.e., Pickering) emulsions and foams, where stabilization is achieved through the binding of particles to fluid interfaces. In many such applications, the interface could be subjected to deformations, producing compression and shear stresses. Besides the physicochemical properties of the particle, their behavior under flow will also impact the performance of the resulting system. This review article provides a synopsis of interfacial stability and rheology in particle-laden interfaces to highlight the role of the Janus motif, and how particle anisotropy affects interfacial mechanics.

Investigating the hydrolytic degradation of PLA/PCL/ZnO nanocomposites by using viscoelastic models

“…It is well-known that a shift in viscoelastic behavior of blends is observed compared with that of the matrix due to the emergence of an elasticity associated with the interface region, which inserts difficulties for the models to anticipate the rheological behavior of blends, correctly. [68,69] It would be more complicated, if a nanoparticle is incorporated into the system, especially if it brings various elastic effects and even contradictory ones. [45] Numerous phenomenological models have been proposed to describe the behavior of the blend from the viscoelastic behavior point of view.…”

Water–Sulfuric Acid Foam as a Possible Habitat for Hypothetical Microbial Community in the Cloud Layer of Venus

“…On Earth, stable natural foam structures are based on specific compounds present in the water phase enhancing surface tension and stabilizing the foam [42][43][44]. A good example of the generation of stable water foams is the boiling of milk.…”

“…Another large group of inclusions which could stabilize the hypothetical habitable foam of Venusian clouds can be composed of abiogenic compounds such as metal particles, highly dispersed mineral powders, silica particles, and other inorganic compounds or crystal structures [35,42,51,53,54]. Moreover, the examples of inorganic foams formed from materials common on Earth and under temperatures typical for Venus are known.…”

Tuning the rheology and microstructure of particle-laden fluid interfaces with Janus particles

“…Janus particles -heterogeneous colloids composed of two or more distinct regions with different surface propertieshave been extensively studied in recent years as promising surface-active agents that can effectively modify the properties of fluid interfaces [34][35][36][37][38]. While they have been already employed to control the collapse mechanism of fluid interfaces [39,40] and reduce surface tension [41][42][43][44][45][46][47], the potential of Janus particles in modifying the rheology of fluid interfaces has not been explored heretofore.…”