Single light emitters in the confinement of polymers

This thesis presents developments in the field of nanoscale probing of polymers. New experimental methods based on single molecule fluorescence detection were developed and applied to polymer studies. Localization of, and communication with individual fluorescent molecules embedded in a glassy polymer or immersed in a polymer melt have been realized by using various, optical techniques e.g. Scanning Confocal Microscopy and Wide-Field Microscopy. Location of single molecules as well as their orientation, emission spectra or fluorescence lifetime have been followed in time. This allowed us to perform dynamical studies in the time domain. Since full distributions of single molecule behavior (e.g. rotational diffusion constants, fluorescence lifetimes) were obtained, systems with heterogeneous dynamics could be clearly identified and sub-ensembles, which could be characterized with different dynamic properties, were separated and investigated. Besides polymer probing studies, it was also shown how relatively simple structures can be prepared and used to engineer the emission properties of single molecules. In particular, the fluorescence emission of single molecules in thin polymer films and in electrospun polymer fibers was shown to depend on the size of the structures.