Unique phenomenon discovered as gel shifts to a liquid, then back to a gel and back again

In a strange twist, researchers have accidentally discovered the a flowing suspension of a gel, called a sol, becomes solid gel again when it’s diluted further – going against all previous conventions.

This odd behaviour was discovered accidentally by master’s student Cyprien Muller at Eindhoven University of Technology, the Netherlands, working in Bert Meijer’s group. Muller was investigating whether surfactants could interact with supramolecular polymers. Muller and his mentor Jesús Mosquera were seeing if, by adding surfactants, they could avoid making a hydrogel when the supramolecular polymers were concentrated. And they were right. The surprise came next when they accidentally added more water. As the mixture was diluted further, the sol became a gel again.