Spectroscopical properties of a DTAF-labeled hydrophilic–hydrophobic copolymer in water and surfactant micelles

Abstract

Emulsion copolymerization of hydrophilic α-tert-butoxy-ω-vinylbenzyl-polyglycidol macromonomer with styrene yields core–shell microspheres and a water-soluble copolymer fraction. This copolymer has a higher content of hydrophilic polyglycidol attested by 1H NMR. Further information is acquired by labeling the copolymer with 5-(4,6-dichlorotriazinyl)aminofluorescein (DTAF) and making absorption and fluorescence studies. The acquired data on aqueous solution of labeled copolymer without (L) and with micelles of dodecyltrimethylammonium chloride (LD), sodium dodecylsulfate (LS) and hexaethyleneglycol mono n-dodecyl ether (LE) reveal that the dianionic and anionic tautomers of the DTAF-label are apparent and concordant with the recorded spectrophotometric pKa values. The emission intensities, quantum yields and lifetimes obey the sequence LE < LS < L < LD. They are along with the increasingly deprotonated forms of the fluorophore and unveil that the micelle-label interactions depend on the surfactant.