A straightforward method of analysis of first-order processes with distributed parameters

A method has been put forward allowing direct determination of parameters d escribing the kinetics of first-order processes controlled by distributions of rate constants. The method consists in examining the time dependence of the (concentration X time) product: the maximum of the resulting function is directly related to the time constant of the kinetic process, and its wi dth to the width of the distribution of the activation energies. The method has been applied to interpret the kinetics of bleaching reactions in solut ions of photochromic polymers containing spiropyrane moieties attached to t he poly(methyl methacrylate chain). (C) 1998 Elsevier Science B.V. All righ ts reserved.