A new polymer material from clay and glue has been developed which is as strong as steel. This new polymer is transparent and has tremendous strength. This new polymer is biodegradable, requires very little energy to manufacture and has a very low cost of manufacture. It is made of layers of clay nanosheets and a water-soluble polymer that shares chemistry with white glue. University of Michigan researchers have created this composite plastic by mimicking a brick-and-mortar molecular structure found in seashells. Further development could lead to lighter, stronger armor for soldiers or police and their vehicles. It could also be used in microfluidics, biomedical sensors and valves and unmanned aircraft. The plastic could be used to reduce the energy required to separate gases in chemical factories, improve microtechnology such as microchips and produce lighter, stronger armour for the police and their vehicles.

The scientists have solved a problem that has confounded engineers and scientists for decades: Individual nano-size building blocks such as nanotubes, nanosheets and nanorods are ultrastrong. But larger materials made out of bonded nano-size building blocks were comparatively weak. Until now scientists had difficulties transferring the strength of individual nanosheets or nanotubes to the entire material. This has been solved by the team that has demonstrated that one can achieve almost ideal transfer of stress between nanosheets and a polymer matrix.
The researchers created this new composite plastic with a machine they developed that builds materials one nanoscale layer after another. The robotic machine consists of an arm that hovers over a wheel of vials of different liquids. In this case, the arm held a piece of glass about the size of a stick of gum on which it built the new material. The arm dipped the glass into the glue-like polymer solution and then into a liquid that was a dispersion of clay nanosheets. After those layers dried, the process repeated. It took 300 layers of each the glue-like polymer and the clay nanosheets to create a piece of this material as thick as a piece of plastic wrap. Mother of pearl, the iridescent lining of mussel and oyster shells, is built layer-by-layer like this. It�s one of the toughest natural mineral-based materials.
Polyvinyl alcohol - the glue-like polymer used in this experiment, was as important as the layer-by-layer assembly process. The structure of the "nanoglue" and the clay nanosheets allowed the layers to form cooperative hydrogen bonds, which gives rise to "the Velcro effect." Such bonds, if broken, can reform easily in a new place. The Velcro effect is one reason the material is so strong. Another is the arrangement of the nanosheets. They�re stacked like bricks, in an alternating pattern. In a brick-and-mortar structure, any cracks are blunted by each interface.