Electron reactivity in liquid hydrocarbon mixtures

Abstract

The electron current in neopentane–n-hexane mixtures, produced by a few nanoseconds X-ray pulse in the presence of external electric field, has been observed in the nanosecond–microsecond range. The form of the time dependence of the electron current has been shown to vary with dose per pulse and is analysed accordingly. The electron mobilities μ e are thereby determined in the mixtures. The rate constant of electron–ion recombination, k r , is proportional to the mobility over the wide range of μ e The rate constant for electron scavenging, k s by CC1 4 varies with √μ e ; k s for C 2 H 5 Br shows a maximum for a mixture with the mole fraction of n-hexane, x h = 0.48. The results for k s obtained for the mixtures agree with those by Allen and co-workers for various neat hydrocarbons. Further, the mechanism of electron transport in non-polar liquids is discussed. Using experimental results for V 0 and E a for the mixtures (the energy of the electron in its quasifree state and the activation energy of μ e , respectively) V 0 is expressed by a linear function of E a : V 0 = −0.42 + 2.6E a at room temperature and μ e is correlated with V 0 as an empirical formula μ e = 125/[1 + 360 exp (15V 0 )] based on a trapping model.