Journal of Polymer Science Part A: Polymer Chemistry, Vol.50, No.1, 52-60, 2012
Well-Defined Diblock Copolymers Possessing Fluorescent and Metal Chelating Functionalities as Novel Macromolecular Sensors for Amines and Metal Ions
The amino-and metal-ion sensing capability of a novel type of well-defined block copolymers based on 9-anthrylmethyl methacrylate (AnMMA; hydrophobic, fluorescent) and 2-(acetoacetoxy) ethyl methacrylate (AEMA; hydrophobic, metal chelating) has been investigated in organic media. AEMA(x)-b-AnMMA(y) diblock copolymers were prepared for the first time using reversible addition-fragmentation chain transfer (RAFT) polymerization. All polymers were characterized in terms of molecular weights, polydispersity indices and compositions by size exclusion chromatography and (1)H NMR spectroscopy, respectively. The glass transition (T(g)) temperatures of the AEMA(x) and AnMMA(x) homopolymers and the AEMA(x)-b-AnMMA(y) diblock copolymers were determined using differential scanning calorimetry. These systems were evaluated toward their ability to act as effective dual chemosensors (i.e., amino- and metal-ion sensors) in an organic solvent (chloroform). More precisely, the fluorescence intensity of both the AnMMA(x) homopolymers and the AnMMA(x)-b-AEMA(y) diblock copolymers in solution exhibited a significant decrease in the presence of triethylamine. Moreover, the presence of iron (III) cations were also found to significantly affect the fluorescence signal of the anthracene moieties when those were combined in a block copolymer structure with the AEMA units, due to complex formation occurring between the beta-ketoester groups of the AEMAx segment and the cations. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 52-60, 2012