Jingsan Xu, an associate professor of chemistry at Queensland University of Technology, developed the foam so it could be sprayed onto the surface of an oil spill to absorb the waste extremely quickly.
The same principal could also be applied to spills in the home with cooking oils—and skin cosmetics. The foam can then be easily scraped away for safe disposal.
“The key to saving the environment from maximum damage from an oil spill is to mop up the oil as quickly as possible,” said Dr Xu.
“So what we have focused on is the adaptability and possibilities associated with surfactants which are already widely used in research, industrial production and our daily lives.”
Dr Xu and his team have now created what they call a “hybrid surfactant” by combining an oil-soluble molecule, stearic acid, with water-dispersible alumina nanofibres via chemisorption at the oil−water interface.
Surfactants are compounds that lower the surface tension between two liquids, between a gas and a liquid, or between a liquid and a solid—in other words, they can act as detergents, wetting agents, emulsifiers, foaming agents and dispersants.
“Our hybrid surfactant exhibits reversible switching between hydrophilic molecules which are attracted to water, and lipophilic ones, which are able to dissolve in fats, oils, lipids, and non-polar solvents by manipulating the adsorption-desorption volume of stearic acid attached to the alumina nanofibres,” he continued.
“Therefore, the emulsions stabilised by this organic−inorganic hybrid can reversibly transform between oil-in-water and water-in-oil type by simple mechanical manipulation.”
These emulsion are widely found in cosmetics. Stearic acid is natural and occurs in many animals and plants, while alumina widely exists in industry and households.
The QUT approach can be translated into beauty and skincare formulation since different people have different types of skin, which either work well with oil-based or water-based products.
“An emulsion that can be reversible and switch between working with water or with oil, it could have significant potential in make-up,” said Dr Xu.
“I think these emulsions might be groundbreaking for cosmetics. The chemistry is fundamentally intriguing; they have even more applications in cosmetics than in oil spills,” said Dr Xu.
“I’m now trying to find an industry partner to be involved in our chemistry. It is very exciting to bring this to market in commercialised products,” he added.