Imagine a polymer with removable parts that can deliver something to the environment and then be chemically
regenerated1 to function again. Or a polymer that can lift weights, contracting and expanding the way muscles do. These functions require polymers with both
rigid2 and soft nano-sized
compartments3 with extremely different properties that are organized in specific ways. A completely new
hybrid4 polymer of this type has been developed by Northwestern University researchers that might one day be used in artificial muscles or other life-like materials; for delivery of drugs, biomolecules or other chemicals; in materials with self-repair
capability5; and for replaceable energy sources.
"We have created a surprising new polymer with nano-sized compartments that can be removed and chemically regenerated multiple times," said materials scientist Samuel I. Stupp, the senior author of the study.
"Some of the nanoscale compartments contain rigid conventional polymers, but others contain the so-called supramolecular polymers, which can respond rapidly to
stimuli6, be delivered to the environment and then be easily regenerated again in the same locations. The supramolecular soft compartments could be
animated7 to generate polymers with the functions we see in living things," he said.
Stupp is director of Northwestern's Simpson Querrey Institute for BioNanotechnology. He is a leader in the fields of nanoscience and supramolecular self-assembly, the strategy used by biology to create highly
functional8 ordered structures.
The hybrid polymer cleverly 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.
The study will be published in the Jan. 29 issue of Science.