Particle-laden fluid/fluid interfaces: physico-chemical foundations

Abstract

Particle-laden fluid/fluid interfaces are ubiquitous in academia and industry, which has fostered extensive research efforts trying to disentangle the physico-chemical bases underlying the trapping of particles to fluid/fluid interfaces as well as the properties of the obtained layers. The understanding of such aspects is essential for exploiting the ability of particles on the stabilization of fluid/fluid interface for the fabrication of novel interface-dominated devices, ranging from traditional Pickering emulsions to more advanced reconfigurable devices. This review tries to provide a general perspective of the physico-chemical aspects associated with the stabilization of interfaces by colloidal particles, mainly chemical isotropic spherical colloids. Furthermore, some aspects related to the exploitation of particle-laden fluid/fluid interfaces on the stabilization of emulsions and foams will be also highlighted. It is expected that this review can be used for researchers and technologist as an initial approach to the study of particle-laden fluid layers.

Interfacial tension driven adsorption of MnO2 nanoparticles at the liquid/liquid interface to tailor ultra-thin polypyrrole sheets

“…The adsorption of nanoparticles (NPs) at interfaces is a thermodynamically favorable and spontaneous process since the NPs tend to minimize the interfacial tension, interfacial area, and interfacial energy (Helmholtz free energy). [13][14][15][16] The adsorption/desorption behavior of NPs across the L/L interface is governed by variation in interfacial free energies as validated using molecular dynamic simulations. 17 Furthermore, the stability of the assembled NPs determines the stabilization of the interface of two immiscible liquids.…”

Fluid Films as Models for Understanding the Impact of Inhaled Particles in Lung Surfactant Layers

“…LS is a mixture containing mainly lipids and proteins which overlays the inner wall of alveoli in mammals (i.e., the alveolar lining) [7,22], contributing to two very important physiological aspects: (i) regulation of the mechanical properties of the alveoli during breathing, preventing alveolar collapse during exhalation [23][24][25], and (ii) protection against inhaled matter, mainly pathogens (e.g., SARS-CoV-2) [7,[26][27][28][29][30][31]. Therefore, any dysfunction on the LS mechanical properties or modification of its composition may be harmful for health [32][33][34][35][36][37][38]. However, to date there is an important lack of knowledge about the true impact of inhaled particles in the respiratory cycle, even though it is clear that the deposition of particles on LS alters the breathing mechanics, the use of particles, even inhaled ones, in therapy and diagnosis is undergoing continuous growth [39][40][41][42][43].…”

Soft Colloidal Particles at Fluid Interfaces

“…The assembly of colloidal particles at fluid interfaces is currently exploited in a broad range of industrial and technological fields, ranging from food, oil, and cosmetic industries to pharmaceutical formulations, and from the manufacturing of advanced coatings to biomedical applications [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. In particular, the use of soft colloidal particles gained importance in the above applications in recent years [ 9 , 10 ].…”