Novel hybrid polymer could deliver a 'life force'
29 January 2016
A new hybrid polymer has been developed by Northwestern University researchers that might one day be used in artificial muscles or other life-like materials.
“We have created a surprising new polymer with nano-sized compartments that can be removed and chemically regenerated multiple times,” says materials scientist, Samuel Stupp. “Some of the nanoscale compartments contain rigid conventional polymers, but others contain the so-called supramolecular polymers, which can respond rapidly to stimuli, be delivered to the environment and then be easily regenerated again in the same locations. The supramolecular soft compartments could be animated to generate polymers with the functions we see in living things.”
The hybrid polymer combines the two types of known polymers: those formed with strong covalent bonds and those formed with weak non-covalent bonds, well known as 'supramolecular polymers'. The integrated polymer offers two distinct 'compartments' with which chemists and materials scientists can work to provide useful features.
“We can create active or responsive materials not known previously by taking advantage of the compartments with weak non-covalent bonds, which should be highly dynamic like living things," says Stupp. "Some forms of these polymers now under development in my laboratory behave like artificial muscles.”
Polymers get their power and features from their structure at the nanoscale. The covalent rigid skeleton of Stupp’s first hybrid polymer has a cross-section resembling a hard core with arms spiralling out. In between the arms is the softer 'life force' material. This is the area that can be animated, refreshed and recharged.
“The fascinating chemistry of the hybrid polymers is that growing the two types of polymers simultaneously generates a structure that is completely different from the two grown alone,” says Stupp.
An article describing this work is published in the journal, Science.