New ID pictures of conducting polymers discover a surprise ABBA fan

STSTM image showing how the detail of the structure of C14DPPF-F can be seen — this new technique giving a submolecular resolution of the polymer backbone and the interdigitation of the alkyl side chains. White arrows indicate gaps in the alkyl chain interdigitation. Credit: University of Warwick

The first ever detailed pictures of the structure of conjugated polymers have been produced by a research team led by Professor Giovanni Costantini at the University of Warwick.

The ability of these polymers to conduct electricity makes them highly sought after, but until now they could also be described as extremely camera shy as there have been no easy means to determine their structure. The new technique allows researchers not only to determine it but to actually clearly see it with their own eyes.

Conjugated polymers are able to conduct electricity because they are a chain of conjugated molecules where electrons can move freely due to their overlapping electron p-orbitals. Effectively, they are excellent molecular wires. Moreover, they are akin to semiconductor materials (they have energy gaps), so they can be used for electronic (plastic electronics) and photovoltaic (organic solar cells) applications.

Modern functional polymers are often copolymers, that is, they are made by an (ideally regular) sequence of different monomers. The order of these monomers is essential to their optoelectronic properties which can be severally damaged by errors in how the monomers actually link up in a chain to form the polymer (so-called polymerization errors occurring during the synthesis of these materials). However, detecting the nature and exact position of these errors has proved problematic with current analytical methods. Mass spectrometry does not provide a solution, as shorter polymer chains are typically more likely to be ionized and thus tend to be overrepresented in the spectra.

Read more: New ID pictures of conducting polymers discover a surprise ABBA fan

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