Fluorescence spectra of pyrene labeled polyelectrolytes with sulfonate groups in water and DMSO

1-Pyrenylmethyl-methacrylamide (PyMA) was synthesized, and applied to copolymerizing with AMPS and DMAA to get a series of pyrene labeled polymers with sulfonate groups. The molar fraction of sulfonate monomer AMPS in these samples varies from 0. 032 6 to 0. 896. In DMSO and water, the profile of fluorescence spectrum of pyrene labeled polyelectrolytes is analogous to that of PyMA when F-AMPS < 0. 449, while the [0,1] emission peak abruptly increased as F-AMPS greater than or equal to 0. 449, The so-called polarity scale of pyrene, I-1/I-3 Of pyrene labeled polyelectrolytes in DMSO and in water decreases gradually with increasing FAMPS representing the charge density of the samples. I-1/I-3 also decreases gradually with the increase in polymer concentration in water. The results imply that there exists the hydrophobic aggregation through locally electrostatic attraction even in polyelectrolyte/polar solvent system, in contrast to the traditional polyelectrolyte theory. However, I-1/I-3 Of these polyelectrolytes remains almost a constant with increasing NaCl concentration of aqueous solution up to 0. 75 mol/L, indicating the electrostatic attraction cannot be simply screened.