Synthesis of Site-Specific Dye-Labeled Polymer via Atom Transfer Radical Polymerization (ATRP) for Quantitative Characterization of the Well-Defined Interchain Distance.

Abstract

Novel difunctional initiators that incorporate Förster/fluorescence resonance energy transfer (FRET) pairs are generated to carry out atom transfer radical polymerization of styrene, methyl methacrylate, and n-butyl methacrylate monomers by an efficient manner. Based on the chemical structures of the initiators, the locations of the fluorophore moiety are dictated to be in the center of the chain with accurately quantified chain functionality (>90% labeling ratio). The site-specific integration of FRET dyes into separate polymer chain centers allows for characterization of the well-defined interchain distance quantitatively based on the response between these fluorescent probes. The reliability of this technique is verified in bulk state, which is in well agreement with the theoretical ones. This well-defined FRET system is expected to be a promising candidate to provide a distinct physical image at a microscopic level regarding scaling chain dimension, chain interpenetration, and polymer compatibility.