Fluorescence recovery after two-photon bleaching for the study of dye diffusion in polymer systems
|Title||Fluorescence recovery after two-photon bleaching for the study of dye diffusion in polymer systems|
|Publication Type||Journal Article|
|Year of Publication||2003|
|Authors||Van Keuren, E., and Schrof W.|
Fluorescence recovery after two-photon photobleaching (TP-FRAP) was used to characterize the diffusion in polymer thin films. Using a two-photon/confocal microscope, a region was bleached inside a fluorophore-doped poly(vinyl alcohol) film. An ellipsoidal form of this spot was observed, and a simple form was derived for the fluorescence recovery at the spot center, enabling the local fluorophore diffusion coefficient to be determined. A series of films with varying amounts of added plasticizer were measured to determine the relation between plasticizer content and diffusion coefficient. In a second set of films with inhomogeneous distribution of plasticizer, three-dimensional maps of the diffusion coefficient were measured using TP-FRAP followed by confocal imaging. From these maps and the calibration curves, three-dimensional maps of the local plasticizer concentration were determined.