Gallery
Collective oil-coated bubble bursting
Collective oil-coated bubble bursting tends to generate jet drops with smaller sizes, greater overall numbers of drops and higher droplet ejection heights than bare bubble bursting at either clean or surfactant-laden aqueous surfaces, as shown in the figure. The droplet size is one key parameter in predicting its residence time and transport, as small droplets are more easily lifted by turbulent eddies. These contaminant-laden drops smaller than 10 μm in diameter could pose a higher risk of pollutant spread or infection as they can penetrate farther into the respiratory tract than larger drops. The oil-coated bubbles in our experiments could typify the ubiquitous contaminated or compound bubbles in the oceans, and bubble-bursting jet drop particles have been found to contain different compositions with stronger ice nucleating abilities than film drop particles. Our discovery may therefore improve chemical transport modelling related to bubble-driven fluxes in the context of sea spray aerosols.
Bubble cap rupture
Film drops produced from bursting bubble on the sea surface microlayer can be enriched with micro-organisms or bacteria and transported to the atmosphere. Once a bubble is created in a bulk solution, the bubble rises with small particulates to the surface and forms a spherical cap at the surface. The shape of the cap remains constant before the bubble spontaneously ruptures, often fragmenting into film droplets as shown in the picture. Investigating bubble bursting behavior paves the way to predict the transmission of small particulates, such as microplastics, bacteria, or even viruses from sea surface and other forms of water sources.
Bubble bursting jets at an oil-covered aqueous surface
When a bubble bursts and produces a jet at an oil-covered aqueous interface, the oil layer greatly influences the hydrodynamic process and modify the drop size and velocity. After the bubble bursts, the oil layer spreads to the bottom and damps the capillary waves simultaneously. As a result, a faster and thinner jet emerges with a more viscous and thicker oil layer. This study advances our understanding of the interplay between bubbles and contaminated surfaces.
Multi-vesicular Vesicles
This video highlights different sealing behavior when a multivesicular vesicle (a vesicle containing many smaller vesicles) bursts. These two vesicles were placed in the same hypotonic solution. Both vesicles swell due to the osmotic imbalance, eventually bursting under the increasing strain. Once the strain is released, each vesicle will spontaneously reseal. In one case the sealing occurs cleanly, while in the second, there is a tangle of lipid protrusions on the surface. Understanding what drives clean and tangled resealing could add insight into physiologically relevant membrane behavior as well as pointing the way to more precise artificial drug delivery systems.
Transformations
A sequence of spontaneous shape transformations of a giant unilaminar vesicle. It is nearly 5 microns across, about the size of a single red blood cell. Thermal oscillations of the membrane drives the changes seen in this image. This models the shape energetics of red blood cells, a feature crucial for transporting oxygen throughout the body.
Nanoparticle Galaxy
When an aqueous suspension of nanoparticles consisted of polymers is exposed to air, the adsorption and aggregation of those nanoparticles form a glaxy-like structure at the air-water interface. This top-view image was captured by a confocal microscope. The light came from the fluorescent emission of dye molecules encapsulated in the nanoparticles. The area shown in the image is approximately 2.5 by 2.0 mm
Blooming Flowers
When a small quantity of oil (a linear alkane) is deposited on the surface of an aqueous solution of detergent molecules, the oil spreads into a thin film and then ruptures. Multiple holes appear in the film, and the oil ridges around the growing holes transform into intricate petal-like patterns in a process that is similar to the breakup of a liquid filament into droplets. These films with growing holes are like gardens of blooming interfacial flowers. This top-view image was captured with a standard digital SLR camera and macro lens. The rainbow colored patterns are created by the interference of light from an LED panel and they reveal the structure of the oil film. The area shown in the image is approximately 1.7 by 1.3 cm.
Dancing Fringes
When you look at a small bubble at the interface, you will see dancing interference fringes induced by marginal regeneration. The dance of the interference fringes, which represents iso-thickness lines of the bubble film, results from the convection motion developed over the bubble cap. This motion consists of the periodic emission of spaced plumes from the edge of the cap. Once they have left the pinching zone, the thinner plumes rise because of their positive buoyancy with respect to the surrounding thicker portions of the film. The area shown in the image is approximately 2.0 by 0.5 cm.