Polymer–dye interactions as a tool for studying phase transitions

The thermosensitive polymer poly(N-isopropylacrylamide) known as PNIPAM undergoes a phase transition at 32 °C in an aqueous solution. In this manuscript, the phase transition of PNIPAM was investigated by looking on the photophysical properties of embedded water soluble carbocyanine dyes (S0522) using steady state and time resolved ensemble and single molecule fluorescent spectroscopy. Changes in the polymer structure above and below the phase transition temperature are directly reflected through the photophysical properties of the dye.