A new material class: glassy gels

Researchers have created a new class of materials called “glassy gels” that are very hard and difficult to break despite containing more than 50% liquid.

The so-called glassy gels combine properties of two distinct classes of materials: gels and glassy polymers. The latter are used to make things like water bottles and airplane windows; they are hard and brittle. Gels, on the other hand, contain liquid and are soft and stretchy.

The glassy gels combine the best of both worlds: the material is as hard a glassy polymer, but when applying enough force, it can stretch up to five times its original length, rather than breaking or cracking. It returns to its original size when heat is applied. In addition, the surface of the glassy gels is highly adhesive, which is unusual for hard materials.

The key lies in the fact that glassy gels contain 50 per cent liquid, which makes them more efficient conductors of electricity than common plastics that have comparable physical characteristics. Despite the high liquid content, the material does not evaporate or dry out. One strange thing about new material class is that it is adhesive. The researchers are not sure why. The production process is also relatively easy using any type of mould, or through 3D printing. Various types of polymers can be used to make the glassy gels, though not all are suitable.

Photo: Meixiang Wang, Nc State University