That, according to the abstract of Fossum’s article, titled, “Transition from glass- to gel-like states in clay at a liquid interface.”
His work presents a way to keep oil and water separated by a thin layer of clay. The technology relies on carefully calibrated ratios of salt and water. “Clay particles repel one another in water that does not contain salt. In this case, the clays form the same kinds of nanostructures that are found in glass materials,” explains The Norwegian University of Science and Technology in a press item about the newly published research.
“In contrast, clay particles in saline water tend to aggregate and form a kind of gel consisting of a nano-network of clay particles.”
By observing the behavior of particles, Fossum and his team of researchers can “infer that clay trapped at quasi two-dimensional interfaced between oil and water also exhibit confined glass-like or gel-like states,” as they write in the abstract.
While more research is need to better understand what’s happening. Fossum has demonstrated “that there are micrometer-thick gel structures formed as specific salt concentrations in water with sufficient mechanical strength to prevent oil droplets in emulsions from merging with one another,” according to the university press item.
And that structural technology, Fossum believes, could well have applications in cosmetics.
The research was conducted with fairly simple inputs: colloidal clay, NaCl salinities of 0 to 0.1M, and purified paraffinic mineral oil.
And, the published findings outline observations made using conofocal Raman microscopy. The researchers documented mechanical behavior, interface tension, dilational interfacial rheological properties, aging time, and more.
The full open-access article can be found online here.