As in the spontaneous micellization processes of surfactants in
water, the final supramolecular architecture of the colloids is
supposed to be entropically driven by the arrangement of the
monomer chains within the single bilayer, in which the carboxylic
heads are freely-exposed to the medium and the hydrocarbon tails
form hydrophobic domains to avoid interactions with the solvent.
In our opinion, the PCDA packing in mono- or multi-bilayered
fashion is produced during the prolonged incubation step of the
synthesis and maintained after the polymer formation. Regardless
of their stratification degree, a large number of carboxylic groups
protrude from the bpPCDA/AgNPs outer surface. This fact justifies
the unusual high stability of the nanohybrids in water, so allowing
their storage in aqueous suspension for months even at room
temperature.