Reaction kinetics in dense two-dimensional polymer solutions : an excimer probe study

We report measurements of the time dependent reaction rate of excimer formation in two-dimensional solutions of a polymerized amphiphile with partially pyrene-labelled chains in monolayers at the air-water-interface. We find a time dependent reaction rate for excimer formation obeying a power law r(t) ∞ t -β . The exponent β has a value of 0.22±0.12. This value is consistent with β=1/4, as has been predicted for bimolecular diffusion-controlled reactions in two-dimensional polymer melts by de Gennes. The measurements demonstrate the usefulness of the excimer technique to explore polymer dynamics