Self-dissociation of water-soluble PANa/ETC nano-aggregates

Complexation between poly(sodium acrylate) (PANa) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide methiodide (ETC) in water, which leads to the formation of vesicle-like aggregates, was studied. Different from reported nano-aggregates of polymer complexes that may dissociate when being stimulated, the nano-aggregates of PANa/ETC complexes dissociate automatically in the aqueous solution at ambient environment, exhibiting a behavior similar to that of the nano-aggregates composed of degradable polymers. In the newly formed nano-aggregates, there are hydrophobic domains with a hydrophobicity close to that of hexane. Along with the dissociation, the hydrophobic domains vanish gradually.