Determination of micelle diffusion coefficients with fluorescence correlation spectroscopy (FCS)

Normalized correlation funtion G( τ) of BPEA in Tween 20 at different surfactant concentrations and the FCS curve of the reference dye rhodamine 6G in water. In our study we determined the diffusion coefficient of Tween 20 micelles at different surfactant concentrations (10 −4–10 −2 M) via fluorescence correlation spectroscopy. The hydrophobic fluorescent dye 9,10-bis(phenylethynyl)anthracene, located in the micellar phase, was used as marker for the diffusion of Tween 20 micelles. The hydrodynamic radius of the micelles, R h, was estimated from the diffusion coefficient and compared with literature values from previous studies.