Title

Water-Soluble Copolymers .61. Microstructural Investigation of Pyrenesulfonamide-Labeled Polyelectrolytes: Variation of Label Proximity Utilizing Micellar Polymerization

Document Type

Article

Publication Date

8-28-1995

Department

Polymers and High Performance Materials

Abstract

Synthesis of a series of pyrenesulfonamide-labeled polyelectrolytes viith varied label proximities has been accomplished by a micellar polymerization technique. The solution properties of these terpolymers consisting of acrylamide (AM), acrylic acid (AA), and N-[(1-pyrenylsulfonamido)ethyl]-acrylamide (APS) are examined using viscometry, light scattering, and fluorescence spectroscopy. Classical light scattering indicates high molecular weights (>1 x 10(6)) and very good polymer solvation even at high NaCl concentrations (A(2) similar to 10(4) cm(3) mol/g(2)). Viscometry and dynamic light scattering studies indicate no interpolymer aggregation of the hydrophobic APS labels. Also, no intermolecular associations are evident through measurement of I-E/I-M as a function of terpolymer concentration in 0.5 M NaCl or at pH 3 and 7. Further photophysical results are interpreted on the basis of intramolecular excimer formation. Steady-state fluorescence emission studies indicate that I-E/I-M scales with the surfactant to APS ratio (SMR) in polymerizations. Also, I-E/I-m is a linear function of n, the initial number of APS monomer molecules per micelle. Steady-state excitation and time-resolved fluorescence emission studies have been utilized to probe the microenvironment surrounding the APS labels at varying polymer concentration, electrolyte concentration, and pH values.

Publication Title

Macromolecules

Volume

28

Issue

18

First Page

6175

Last Page

6182