Imagine smartphones that bend, twist and stretch like rubber. Or 3D-printed material that mimics the pliable characteristics of human cartilage found in knees, noses and ears.
In contrast to the stringlike linear polymers found in materials such as polyethylene and Teflon, ring polymers are closed loops with no beginning or end.
It’s not much of a stretch for Ting Ge, an assistant professor in chemistry and biochemistry. Ge has just begun a five-year CAREER Award from the National Science Foundation to delve deeper into the field of ring polymers, the unique mechanical properties of which could find their way into several industrial and even bio-implant applications.
In contrast to the stringlike linear polymers found in materials such as polyethylene and Teflon, ring polymers are closed loops with no beginning or end. A linear polymer can be compared to an ordinary rubber band; as it is pulled, it gets bigger, but resistance grows proportionally until it breaks. As the rubber band becomes taut, it no longer feels as soft as it did in its unstretched state.
Ge’s computer simulations show that a rubber band containing cross-linked ring polymers could be stretched far larger than an ordinary band but with little corresponding resistance. The amount of force needed to stretch it even wider would barely increase, and the band, though stretched, would retain its soft quality. It’s not difficult to picture such a material being compatible with human tissues or skin, Ge says, or perhaps in new formulations for vehicle tires.
“This is really at the frontier of polymer chemistry,” says Ge, who is applying his knowledge from physics. Both his bachelor’s and doctoral degrees were earned in that field, and his postdoctoral research was in chemistry, mechanical engineering and materials science. “My work is quite interdisciplinary.”