| Abstract
| - Pyrene-labeled amphiphilic hyperbranched poly(sulfone−amine)s (Py-Am-HPSA) with a hydrophilichyperbranched core and different amounts of hydrophobic tails were synthesized by end-capping of pyrene-labeled hyperbranched poly(sulfone−amine) (Py-HPSA) with palmitoyl chloride. The characterization offluorescence showed that the excimer-to-monomer intensity ratio (IE/IM) increased with increasing contentof hydrophobic units in polymers. In the range pH below 7, Py-Am-HPSA displayed the ordinaryconcentration-quenching effect of fluorescence for monomer emission and excimer emission, while theratio of IE/IM monotonically increases with the increase of polymer concentration. With the rise ofconcentration of Py-Am-HPSA, IE/IM increases slightly and then significantly as it reaches the criticalpoint where the concentration is 2−5 g/L. The acidity (or pH) of the aqueous solution has a great influenceon the association behavior of Py-Am-HPSA. In the range pH 6.5−8, the ratio of IE/IM for Py-Am-HPSAincreases dramatically with increasing pH, while that for Py-HPSA only varies a little.
|
