Trapping of Rhodamine 6G excitation energy on cellulose microparticles.

Rhodamine 6G (R6G) was adsorbed on cellulose microparticles and fluorescence quantum yields and decays were measured as a function of dye loading. Though no spectroscopic evidence of dye aggregation was found, a noticeable decrease of quantum yield--after correction for reabsorption and reemission of fluorescence--and shortening of decays were observed at the highest loadings. These effects were attributed to the dissipation of the excitation energy by traps constituted by R6G pairs, leading to static and dynamic quenching produced by direct absorption of traps and non-radiative energy transfer from monomers, respectively.