Dynamic surface tension of complex fluid-fluid interfaces: A useful concept, or not?

Surface tension dominates insect flight on fluid interfaces.

Flight on the 2D air-water interface, with body weight supported by surface tension, is a unique locomotion strategy well adapted for the environmental niche on the surface of water. Although previously described in aquatic insects like stoneflies, the biomechanics of interfacial flight has never been analysed. Here, we report interfacial flight as an adapted behaviour in waterlily beetles (Gal...

Dynamic Organization of Ligand-Grafted Nanoparticles during Adsorption and Surface Compression at Fluid–Fluid Interfaces

Monolayers of ligand-grafted nanoparticles at fluid interfaces exhibit a complex response to deformation due to an interplay of particle rearrangements within the monolayer, and molecular rearrangements of the ligand brush on the surface of the particles. We use grazing-incidence small-angle X-ray scattering (GISAXS) combined with pendant drop tensiometry to probe in situ the dynamic organizati...

A Variational Characterization of Fluid Sloshing with Surface Tension

Sloshing refers to the free surface motion of a fluid in a container. We study the linearized sloshing problem of an incompressible, inviscid, irrotational fluid in a container, where we focus on the regime where the effect of surface tension dominates the effect of gravity. This is especially important in the microgravity environment, where scientists and engineers have worked to improve our u...

Statistics of fluctuating colloidal fluid-fluid interfaces.

Fluctuations of the interface between coexisting colloidal fluid phases have been measured with confocal microscopy. Due to a very low surface tension, the thermal motions of the interface are so slow that a record can be made of the positions of the interface. The theory of the interfacial height fluctuations is developed. For a host of correlation functions, the experimental data are compared...

Dilatational Rheology and Controlled Generation of Microscale Complex Fluid Interfaces