A team of researchers from the University of Konstanz, Germany, discovered a new state of matter of glass: liquid glass.

While glass may seem like a run-of-the-mill material, scientifically, it is something of a mystery. While it may appear solid, glass is anything but conventional. Normally, when a material transitions from a liquid to a solid state, the molecules line up to form a crystal pattern. In glass, this does not happen. Rather, the molecules are frozen in place before crystallisation happens.

Using a model system involving suspensions of tailor-made ellipsoidal colloids, in which the individual particles could move but not rotate, the researchers at Konstanz found a new state of matter: liquid glass. This complex behaviour was not before observed in glass.

Colloidal suspensions are mixtures or fluids that contain solid particles which, at sizes of a micrometre (one millionth of a metre) or more, are bigger than atoms or molecules and therefore well-suited to investigation with optical microscopy.

What the researchers observed were in fact two competing glass transitions: a regular phase transformation and a nonequilibrium phase transformation, interacting with each other. Liquid glass has been theorised but unproven for twenty years.