Illustration:
Dr. Eric M.M. Tan
(August 14, 2015) A
new type of polymer can show that it has changed shape. After exposure to UV
light, the chain-like molecules emit a different colour of light. This opens a
new pathway for research into how viruses function in a cell and how minor
damage in rubbers and plastics can accumulate and lead to rupture. The new
polymers were developed by researchers at Wageningen University, who published
an article on their findings in the Journal of the American Chemical Society on
12 August 2015.
A polymer can be compared to a necklace of small molecules
that are chemically linked together. Polymers are the basis of a huge variety
of natural and artificial materials, from skin, hair and DNA, to the simplest
and most advanced plastics. The properties of these polymer materials are
largely determined by their spatial structure, also known as ‘conformation’.
Polymers can be as straight as uncooked spaghetti, but can
also occur as a tangle of cooked spaghetti. Polymer chains resist changes to
their conformation, for example when they are stretched. This spring-like
effect provides elasticity to rubbers, flexibility to plastics and strength to
the cytoskeleton of the cell. Therefore, to change the conformation of a
polymer, force must be applied to the molecule. But figuring out the exact
conformation of a polymer is particularly difficult, especially if the polymers
are surrounded by many other substances, such as in a cell.