Current Opinion in Colloid & Interface Science最新文献

Dynamic dilational viscoelasticity is an important physical characteristic of interfacial layers because it influences the dynamics and stability of multiphase systems, such as thin liquid films, foams and emulsions. Dilational viscoelasticity depends on many factors. Less studied, but very important, factors are the solubility of the solution components in two contacting liquids, the simultaneous presence of two solution components within a mixed adsorption layer and the curvature of the interface. In this review, we considered several new developments of previously proposed models, which can be used for the analysis of new experimental data. In the presence of such effects, the behaviour of the dilational viscoelasticity becomes more complicated and requires more parameters for its description. An alternative way is to use phenomenological models, which do not identify the particular relaxation processes but propose a description of the dilational viscoelasticity in general terms.

Perovskite solar cells (PSCs) have rapidly advanced as a promising new photovoltaic generation technology. In a decade, a remarkable power conversion efficiency of 26% was achieved, comparable to silicon-based traditional solar cells. However, their stability and sustainability still need to be improved before commercialization. The potential replacement of some of the inorganic components in the PSCs with organic ones could address these concerns as the organic components may offer the advantages of being biodegradable, low cost, and easily processed, with the potential of protecting the perovskite from the ambient environment. Thus, this review focuses on the recent developments in organic electron transport materials (ETMs) and hole transport materials (HTMs). Additionally, machine-learning insights and perspectives for future research directions are proposed for the advancements of PSCs.

Liquid foams, as colloidal systems comprising a dispersed gas phase within a continuous liquid medium, exhibit unique structural and rheological properties beneficial for various industrial and environmental applications. This review synthesizes current knowledge on the fundamentals, stability mechanisms, and practical applications of liquid foams. We first discuss foam structures, transitioning from ball to wet and dry foams, influenced by the liquid fraction and surfactant presence, which also influence the foam’s mechanical and stability properties. We further describe the mechanisms of foam generation (for confined foams), stability, and decay, highlighting the roles of snap-off, lamellae division, and leave-behind in foam formation and the adverse effects of coarsening, gravity drainage, and collapse on foam stability. Additionally, the review covers the rheological behavior of foams under shear stress, illustrating their complex viscoelastic or viscoplastic nature. Finally, we review recent studies of foam injection and displacement in porous structures, utilizing Hele–Shaw cells and microfluidics.

Profile analysis tensiometry (PAT) with drops and bubbles is a successful methodology to characterize liquid–fluid interfaces. Questions about the most suitable size of drops and bubbles have been solved now on the basis of dimensionless numbers. The consideration of the standard deviation between measured and calculated liquid profiles as a sensitive measure for the applicability of PAT provides a tool for its correct use. For solutions of highly surface-active compounds, bulk depletion effects can cause systematic errors in the analysis of adsorption kinetics, equations of state, and the visco-elastic interfacial behavior of liquid adsorption layers. Great progress has been made in measurements of interfacial dilational rheology with large amplitude perturbations providing additional information about structure and dynamics of complex adsorption layers. Also, first attempts are successfully made to use artificial intelligence (AI) to enhance the efficiency of PAT applications. Thus, PAT has established a solid position in surface science.