Alicyclic poly(amide acid) triethylammonium salts having alkyl ester side chains spontaneously self-assembled to form nanoaggregates in water The nanoaggregates of poly(amide acid)s encapsulated a hydrophobic guest molecule, Nile red, within their apolar microenvironment The size of the aggregates and the critical aggregation concentration (CAC) were considerably affected by both side chain length and M-w, of the polymers