ESCAPE RATE OF MUONIUM FROM MICELLES - AS DETERMINED BY COMPETITION KINETICS

A competition was established for the reaction of muonium atoms (Mu) between nitrate ions in water and benzene or styrene solubilized in micelles. The nitrate was 3.3 - times more efficient at inhibiting muonated free radical formation with benzene than with styrene as the radical-producing solute. Kinetic analysis of this system indicates that Mu emerges from micelles, on average, at least three times during its short (ns) lifetime, these being medium sized micelles carrying on average 3 benzene molecules. So Mu is certainly not trapped, nor even localized. Its escape rate is estimated to be approximately 9x10(8) s-1, which is commensurate with an ordinary diffusion time. The results were obtained by determining the yield of muonated free radicals formed within the micelles using muon-level-crossing-resonance spectroscopy.