Effect of charge scavengers on the scavenging of charges of opposite sign. The consequences on the steady state and pulse radiolysis of liquid hydrocarbons

Abstract

The scavenging of positive ions and electrons in hydrocarbons is re‐examined in terms of a model where the mobilities of positive and negative charges both decrease upon scavenging. The phenomenological model is applied to steady state and pulse radiolysis and explicit expressions describing such phenomena are obtained. The quantitative results obtained for cyclohexane by treating the available experimental data in this manner are discussed. Specifically the mobility of the hole is estimated to be ∼ 2 × 10 −2 cm 2 V −1 sec −1 and λ, the constant characterizing the ion recombination processes in pure cyclohexane is interpreted to be ∼ 7 × 10 11 sec −1 , which indicates that half of the original ions recombine in ∼ 1 psec . Estimates of ∼ 7 × 10 11 M −1 sec −1 and ∼ 10 13 M −1 sec −1 are obtained for the rate constants for scavenging of positive ions and electrons respectively. It is shown that the presence of a hole scavenger should affect drastically the time dependent behavior of the secondary negative ions and optimum conditions for experiments of this sort are discussed.