Accordion Folding through Charge-Transfer in Ionenes

Significance

Ionenes are polymers that contain charged groups in the main chain. When long alkyl spacers in-between charged groups are used, ionenes tend to adopt accordion-like structures in certain solvents. This can be promoted by incorporation of donor and acceptor moieties, which can form charge-transfer complexes helping in the folding process. Collapsed structures of this kind, obtained via reversible weak interactions, are interesting for the formation of nanoparticles for encapsulation.