Deciphering Multiple Critical Parameters of Polymeric Self-Assembly by Fluorescence Spectroscopy of a Single Molecular Rotor BODIPY-C12

Comprehensive characterization of self-assembled materials is crucial for a plethora of different applications; however, it remains a tedious multi-instrument process. To tackle this issue, fluorescence properties of a boron-dipyrromethene derivative containing a lipophilic tail (BODIPY-C12) were employed to extensively characterize two self-assembling polymers (Pluronics P123 and F127). We demonstrate that at least five different parameters, i.e., critical micelle concentration, critical micelle temperature, internal microviscosity within the micelles, micelle core phase transition temperature, and the sol-gel transition temperature, are possible to obtain by means of steady-state and time-resolved fluorescence spectroscopy utilizing a single BODIPY-C12 sensor. This represents a unified methodology for multiparameter characterization of supramolecular polymeric structures and their self-assembly processes. This approach is a compelling nondestructive alternative to the conventional use of several different techniques for the same analytical purposes.