Researchers at the University of Groningen in the Netherlands have developed a polymer that adopts a coiled spring configuration at low temperatures and unfolds again upon heating. Furthermore, the molecule can break down into smaller molecules under certain conditions. The Shanghai Tower, with its spiral shape, served as the inspiration for the project following a visit five years ago. A description of the resulting helical polymer was recently published in Nature Chemistry.
Spiraling structures are common in biological molecules. A well-known example is the double helix of DNA; another is the alpha-helix domains in proteins. Various artificial helices have been created, some of which can change their shape. Other synthetic polymers can be recycled into their monomers, but so far, no polymers have been developed that can both change shape and be recycled into their chemical building blocks.