2015
_TECHNOLOGY Materials science

_Strong Enough to Bend

A conductive material created at Drexel is flexible enough to fold into a paper airplane and could find uses in wearable energy storage devices.

_Yury Gogotsi

Gogotsi is the Distinguished University and Bach professor in the College of Engineering and director of the A.J. Drexel Nanomaterials Institute.

_Michel Barsoum

Barsoum is a distinguished professor in the College of Engineering.

Researchers have chemically engineered a new, electrically conductive nanomaterial that is built of layers just a few atoms thick and is flexible enough to fold but strong enough to support many times its own weight.

They believe the film can be used to improve electrical energy storage, water filtration and radio frequency shielding in technology from portable electronics to coaxial cables.

This material is the latest expression of the ongoing research on a family of two-dimensional materials called MXenes, which were discovered at Drexel in 2011.

This development was facilitated by collaboration between Drexel’s Yury Gogotsi and Michel Barsoum, with Jieshan Qiu, vice dean for research of the School of Chemical Engineering at Dalian University of Technology in China.

To produce the flexible conductive polymer nanocomposite, researchers intercalated the titanium carbide MXene, with polyvinyl alcohol — a polymer widely used as the paper adhesive known as Elmer’s glue. They also intercalated with a polymer called PDDA (polydiallyldimethylammonium chloride) commonly used as a coagulant in water purification systems.

The results of both sets of MXene testing were published in the Proceedings of the National Academy of Sciences. The researchers report that the material exhibits increased ability to store a charge over the original MXene; and 300–400 percent greater strength.

Testing also revealed the nanocomposite has hydrophilic properties, which means it could have uses in water treatment systems.

_Time_will_tell

Thin, flexible materials capable of handling an electric charge open up new possibilities for wearable technology — for example, what if we wanted to make the wristband on a watch into the watch’s battery?