A novel shear-stiffening supramolecular material derived from diboron structure

Shear-stiffening polyborosiloxane (PBS), well-known as “silly putty”, “bouncing putty” or “solid-liquid”, has been widely used in protective armors, sport equipment, toys and so on, due to its fascinating anti-impact property. Since it was created during World War II, there has been rare upgrade of the material. Herein, we synthesize a novel shear-stiffening material, polydiborosiloxane (PDBS), through the design of diboron/oxygen coordination bond. It is revealed that the diboron/oxygen coordination bond possesses more coordination states and higher bond energy than the coordination bond between monoboron and oxygen atoms, leading to a shear-stiffening behavior with more solid-like property. Therefore, PDBS exhibits superior anti-impact property and safeguarding performance to PBS. This shear-stiffening material will open up a new horizon for next-generation intelligent armors, dampers and sensors.