Novel polymer displays unlikely structure


Rebecca Pool

Thursday, May 23, 2019 - 16:00
Image: Janus nanocups that could be used to recover oil spills.
In a potential breakthrough for oil-spill recovery, Germany-based researchers have unveiled a novel polymer that forms 'Janus' nanocups during synthesis, with different chemical properties on inner and outer surfaces.
Developed by Professor André Gröschel and colleagues from the Center for Nanointegration (CENIDE), University of Duisburg-Essen (UDE), the so-called Janus nanocups combine an anisotropic shape with an open cavity.
Given this, the researchers reckon the small vessels could be used to capture, transport and release cargo, including drawing in oil from water.
As Gröschel explains, the nanocups are derived from the evaporation‐induced confinement assembly of polymers, called ABC triblock terpolymers.
On adding the terpolymers to a droplet of solvent, the molecules automatically adapt their shape to match the droplet curvature.
Then, as the solvent evaporates, each cup structure shrinks, leaving nanocups lying one inside the other, which can then be separated to produce the Janus nanocups.
As Gröschel highlights, during this process, the triblock terpolymer spontaneously adopts a hemispherical shape with an inner concentric lamella–lamella morphology.
“Cross‐linking and disassembly of the microparticles results in well‐defined Janus nanocups with a different chemistry on the inside and outside,” he writes in Angewandte Chemie. “By synthesizing polymers with an increasing length of the cross‐linkable block, we tune the mechanical stability of the nanocups, which is relevant to control opening and closing of the cup cavity.”
The researchers reckon they can use this principle to fill the small vessels with, say, nanoparticles, that could then draw in oil residues from water or transport substances through an aqueous environment, such as blood.
The researchers also believe the nanocups could be used as nanoreactors with attolitre volumes.
Research is published in Angewandte Chemie.
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