UCD researchers have found a way to create more nanobubbles than ever before, which has the potential to disrupt industries such as brewing.
A new energy-efficient method to generate and release substantial amounts of nanobubbles in water has been discovered by researchers from University College Dublin (UCD). Unlike more familiar bubbles, nanobubbles exist on the nanoscale level where one nanometre (nm) is one billionth of a metre.
By comparison, a DNA molecule is 2.5nm wide and a human hair is between 60,000 and 100,000nm. Writing in Science Advances, the researchers said this new way to generate nanobubbles has the potential to disrupt a number of industries including wastewater treatment, gas storage, food, biopharma and brewing.
These industries would typically work with bigger micron-sized bubbles with a diameter of less than 50 micron, or a millionth of a metre. However, these bubbles decrease in size and disappear underwater due to the rapid dissolution of their interior gas, which limits their industrial potential.
Nanobubbles, meanwhile, are thermodynamically metastable for many months or even longer in contrast to micron-sized bubbles. This means they have enhanced gas-transfer properties and greater industrial potential.
Yet until now, scientists have struggled to find easily controlled ways to create nanobubbles and release them.
Energy-efficient and additive-free
Explaining how the new method works, Prof Niall English of the UCD School of Chemical and Bioprocess Engineering said: “Our new fundamental discovery involves the application of electric fields, which cause transient negative-pressure regions at gas-liquid interfaces, thereby resulting in gas incorporation in liquids in nanoscale-bubble form.
“It is very energy-efficient, additive-free and works for a wide range of gases, and the greatly enhanced gas solubility in water is highly metastable, lasting at least for many months.”
English’s colleague, Dr Mohammad Reza Ghaani, said their breakthrough has multiple commercial applications, including the fermentation process in industrial brewing.
“Working with UCD’s knowledge transfer team at NovaUCD, we have filed patent applications and we are also looking to commercialise the technology through a UCD spin-out company,” he added.