Fluorescence spectroscopy is used to probe local environments within regions of different polarity and hydrophobicity in aqueous aggregates of PEO 109-PPO 41-PEO 109 triblock copolymers. These copolymer aggregates have well characterized microphases in aqueous solution. Concentrations and temperatures for our studies are chosen such that the copolymers are in unimer, micellar, or micellar hydrogel forms. The observed fluorescence spectra and lifetimes from solutions individually labeled with each of the three coumarin probes report on the changes in the local polarity of the core, exterior, interfacial, and corona regions of these copolymer aggregates. This multiple fluorescence probe methodology will be straightforward to apply in general to problems in polymer and biopolymer aggregates, especially those that display strong hydrophobic effects.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry