Dynamic surface properties of sodium N-acryloyl-11-amimoundecanoate and poly(sodium N-acryloyl-11-aminoundecanoate)

Adsorption layers of sodium N-acryloyl-11-amimoundecanoate and poly(sodium N-acryloyl-11-aminoundecanoate) (PAAU-Na) are studied using surface dilatational rheology measurements. It is established that the dynamic surface elasticity values of the studied systems are different, while their surface tension isotherms are almost the same. PAAU-Na solutions containing excess indifferent electrolyte (NaCl) exhibit a conformational transition in a surface layer due to the formation of loops and tails, which penetrate the bulk phase. Slow variations in the surface properties of PAAU-Na solutions with time seem to be caused by the aggregation of macromolecules in the bulk phase. The aggregation process is investigated by scanning probe microscopy.