NMR and fluorescence studies of the self-association behavior of an amphiphilic polyanion bearing hydrocarbon and fluorocarbon hydrophobes

The association behavior of the terpolymers of sodium 2-acrylamido-2-methylpropanesulfonate (NaAMPS), N-dodecylmethacrylamide (DodMAm), and N-(2-(perfluorooctyl)ethyl)methacrylamide (PFOEMAm) (A/H(x)/F(y)) and their reference copolymers of NaAMPS and PFOEMAm (A/F(y)) was characterized using 19F and 1H NMR, steady state fluorescence, and dynamic light scattering techniques in water (or D2O) containing 0.1 M NaCl. The terpolymers formed micelle-like aggregates where hydrophobic microdomains are formed by hydrophobic associations among the perfluorooctylethyl (PFOE) and dodecyl (Dod) groups, the PFOE group exhibiting a stronger tendency for interpolymer association than the Dod groups. A careful analysis of the characterization data led to a conclusion that the hydrophobic microdomain formed from the terpolymer is microscopically phase separated into the fluorocarbon phase and hydrocarbon phase.