Nav: Home

Bouncing bubbles shake up emulsion studies

July 20, 2020

Some of the fastest video cameras ever developed have been used by KAUST researchers to clarify how molecular-scale changes to water surfaces may impact the performance of industrial-scale purifications.

One factor that influences the stability of emulsions is how quickly small bubbles or droplets join together into larger droplets. Ivan Vakarelski, a research scientist in Sigurdur Thoroddsen's lab, notes that this type of coalescence is driven by variables ranging from bubble size, collision speed, and the "freedom" of molecules located at liquid surfaces.

"When liquids contact a solid, they tend to stick due to strong molecular forces. In contrast, a clean liquid exposed to air can move along relatively easily--we call that a mobile interface," explains Vakarelski. "It's a fundamental property that determines the behavior of many foams and emulsions."

Recently, Thoroddsen and his team used their expertise at high-speed imaging to observe collisions between air bubbles formed in a perfluorocarbon, a liquid with similar viscosity to water that can be refined to an ultrapure state. To their surprise, these bubbles did not coalesce as fast as anticipated. Instead, the high mobility of the air- perfluorocarbon interface caused the bubbles to repeatedly bounce off each other before merging.

In their latest work, the KAUST researchers broadened their investigations to the world's most important liquid--water. A clean air-water interface is supposed to be mobile, however, numerous studies suggest they have low molecular freedom because they are highly susceptible to contamination.

To resolve this quandary, Vakarelski helped design an experiment that used thin films of fatty acids to completely immobilize a free water surface. Then, they released millimeter-sized air bubbles that floated to the interface and crashed into it. When images of the rebounding bubbles were compared to ones taken on purified water surfaces, the team saw that the fatty acid film drastically reduced the degree of bouncing.

"A common belief is that once water is exposed to the atmosphere in a laboratory, it's impossible to keep it clean enough to be mobile," says Vakarelski. "However, our study shows that this is not correct--a standard purification device produces an interface that bounces bubbles back quite strongly."

Successful tests of this approach with other liquids, such as ethanol, indicate that bubble analysis could help solve problems in food processing applications as well as chemical production.
-end-


King Abdullah University of Science & Technology (KAUST)

Related Fatty Acids Articles:

The ova of obese women have lower levels of omega-3 fatty acids
A study conducted by researchers from the UPV/EHU, Cruces Hospital, the IVI Clinic Bilbao and Biocruces Bizkaia shows that the oocytes of obese or overweight women have a different composition of fatty acids.
Scientists use light to convert fatty acids into alkanes
Researchers led by Prof. WANG Feng at the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences have reported that photocatalytic decarboxylation is an efficient alternate pathway for converting biomass-derived fatty acids into alkanes under mild conditions of ambient temperature and pressure.
Microbes from humics lakes produced omega-3 fatty acids from micropla
The environmental fate of microplastics has been difficult to trace.
Efficiently producing fatty acids and biofuels from glucose
Researchers have presented a new strategy for efficiently producing fatty acids and biofuels that can transform glucose and oleaginous microorganisms into microbial diesel fuel, with one-step direct fermentative production.
Omega-3 fatty acids tied to fewer childhood asthma symptoms
A six-month study of children from Baltimore City by Johns Hopkins Medicine researchers has added to evidence that having more omega-3 fatty acids in the diet results in fewer asthma symptoms triggered by indoor air pollution.
Could omega-3 fatty acids help prevent miscarriages?
A new study in mice reveals that omega-3s, a type of fat found in fish oil, reduces fetal and neonatal deaths, suggesting they could prevent some miscarriages in women.
Researchers reveal prostate tumors 'fed' by fatty acids
An international multidisciplinary study initiated by Melbourne scientists has shown a link between prostate cancer and the uptake of fatty acids by cancer cells.
A hidden route for fatty acids can make cancers resistant to therapy
Researchers from the lab of Prof. Sarah-Maria Fendt at the VIB-KU Leuven Center for Cancer Biology now demonstrate that certain tumor cells use an alternative -- previously unexplored -- pathway to produce fatty acids.
Sunscreen and cosmetics compound may harm coral by altering fatty acids
Although sunscreen is critical for preventing sunburns and skin cancer, some of its ingredients are not so beneficial to ocean-dwelling creatures.
New Parkinson's disease drug target revealed through study of fatty acids
A new study led by investigators from Brigham and Women's Hospital and Harvard Medical School has provided insights into the role of fatty acids and suggests that inhibiting a specific enzyme can protect against neurotoxicity.
More Fatty Acids News and Fatty Acids Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Biology Of Sex
Original broadcast date: May 8, 2020. Many of us were taught biological sex is a question of female or male, XX or XY ... but it's far more complicated. This hour, TED speakers explore what determines our sex. Guests on the show include artist Emily Quinn, journalist Molly Webster, neuroscientist Lisa Mosconi, and structural biologist Karissa Sanbonmatsu.
Now Playing: Science for the People

#569 Facing Fear
What do you fear? I mean really fear? Well, ok, maybe right now that's tough. We're living in a new age and definition of fear. But what do we do about it? Eva Holland has faced her fears, including trauma and phobia. She lived to tell the tale and write a book: "Nerve: Adventures in the Science of Fear".
Now Playing: Radiolab

The Wubi Effect
When we think of China today, we think of a technological superpower. From Huweai and 5G to TikTok and viral social media, China is stride for stride with the United States in the world of computing. However, China's technological renaissance almost didn't happen. And for one very basic reason: The Chinese language, with its 70,000 plus characters, couldn't fit on a keyboard.  Today, we tell the story of Professor Wang Yongmin, a hard headed computer programmer who solved this puzzle and laid the foundation for the China we know today. This episode was reported and produced by Simon Adler with reporting assistance from Yang Yang. Special thanks to Martin Howard. You can view his renowned collection of typewriters at: antiquetypewriters.com Support Radiolab today at Radiolab.org/donate.