The Concentrational Changes of the Fluorescence Decay Time of Rhodamine B in Ethanol

Abstract

The photoluminescence decay time r of neutral solutions of rhodamine B in ethanol was measured for concentrations c from 10-5 mol l-1 to 10-2 mol l-1 at 295 K. The r(c) curve observed is atypical, showing two regions of decreasing r. The drop over the ränge 4 X 10-4 to 10-3 mol l-1 was explained by the presence of two ionic forms of rhodamine B, and that at concentrations greater than 4 X 10-3 mol 1-1 — by rhodamine B dimers. © 1982, Walter de Gruyter. All rights reserved.