The Polymer and Colloids Group
In 1985, just before I left for sabbatical in Japan, I asked my postdoc J. Martinho, a specialist in diffusion-controlled reactions, to examine possible transient effects in bimolecular excimer formation between pyrenes attached to one end of a polystyrene chain. Unknown to me, this problem was considered unsolvable because excimer dissociation perturbs the pyrene pair distribution in a way that could not be described at that time. Before he nearly quit in frustration, Martinho discovered a method that finessed the problem by simultaneous analysis of the monomer and excimer decays. This opened the door for a very deep investigation of transient effects. From 1987 to the mid 1990s, we published experimental and theoretical papers on partially reversible fluorescence quenching reactions operating under the influence of diffusion. Martinho's efforts on this topic after he returned to Portugal have led to his promotion to Professor.