Probing the association behavior of poly(ethyleneglycol) based amphiphilic comb-like polymer

Amphiphilic comb-like polymer with and without intrinsic fluorophore was synthesized by the esterification of poly(styrene–maleic anhydride) copolymer with Brij35 (polyethyleneglycol (23) lauryl ether). The solution properties of this polymer in aqueous medium were investigated by pyrene solubilization experiment, surface tension, steady-state fluorescence, viscosity and laser light scattering experiments as a function of pH. Surface tension experiments suggest that the polymer is surface active throughout the pH range investigated and surface activity is very much pH dependent. Data from fluorescence, reduced viscosity and light scattering experiments indicate the possibility of two types of aggregates, intramolecular at low pH and intermolecular at high pH. Pyrene solubilization experiments suggest that the partition of hydrophobic molecules to the intermolecular aggregates is energetically more favorable than partition to intramolecular aggregates.