Electron capture in water pools of reversed micelles

Abstract

The rate constants of excess electron attachment to reversed H/sub 2/O-AOT micelles in liquid isooctane were measured by a picosecond pulse-conductivity technique at 22/sup 0/C. Electron attachment rates were less than the diffusion-controlled rate at molar ratios ..omega../sub 0/ =(H/sub 2/O)/(AOT) less than 12 but increased to the diffusion-controlled rate of approx. 10/sup 15/M/sup -1/s/sup -1/ at ..omega../sub 0/ = 37 where the micelle radius was approx. 100A. The transition from nondiffusion-controlled to diffusion-controlled electron attachment implies that free or non-AOT bound water in the micellar water pools is required for efficient electron attachment, which is consistent with earlier NMR, fluorescence, and polarization studies of electron capture by reversed H/sub 2/O-AOT micelles.