When you blow a bubble, it's expected to pop very quickly. They are, after all, fragile creations, where many peculiar physics effects come together in a little shimmery shell. However, a team of physicists has now made one last for a whopping 465 days.
The findings, published in the journal Physical Review Fluids, don’t focus on soap bubbles – at best, those survive a minute or so. Regular bubbles lose liquid through evaporation or gravitational drainage (This instability was actually tested in space). Inner gas also diffuses through the thin membrane of soap and water back into the environment. All of these effects lead to a POP.
Scientists have been studying ways to make bubbles more stable. One method is mixing water and tiny plastic beads and blowing air into them to make a bubble, creating something called a gas marble. The team wondered how long they could actually last – and it turns out that the sky is the limit.
They created bubbles with a mixture of water and nylon particles, and others with that mixture plus added glycerol (also known as glycerin), a substance commonly found in cosmetics. The water and nylon bubbles were stable for a matter of minutes, some popping around an hour in.
The ones where glycerol was added to the mix had a much longer life. The team found that the bubbles lived longer than 100 days, with the sturdiest (certainly a peculiar adjective for a bubble) surviving 465 days. The key is all in the mixture of glycerol and nanobeads that counteract the physical processes that would normally lead the bubble to burst.
"We show that covering a bubble water shell with microparticles inhibits gravity-induced drainage and that further adding glycerol leads to a stable state, wherein the evaporation of water is counterbalanced by the hygroscopicity of glycerol, which absorbs water molecules contained in ambient air," the researchers wrote in the paper.
"This results in bubbles which can keep their integrity in a standard atmosphere for more than one year, with no significant evolution of their radius."
The team could also make different shapes. Long-lasting bubbles are less about amusement and more about applications in the creation of more stable foams, and also ways to trap toxic gases. There is still a lot that's unclear about the properties of the objects, so investigations beyond applications will certainly be interesting.