Electrical processes in nonpolar liquids based on initial transient response and recovery

Experimental and theoretical results for neutral barium petronate solutions in isopar L are reported. The experimental techniques are novel in that th ey include the use of ac conductivity measurements during transient depleti on and recovery. Use is made of a one-dimensional numerical model to extrac t actual ion mobilities. Deviations from a one-dimensional theoretical mode l are shown to be due to a fluid instability which grows in the highly stre ssed space charge regions near the electrodes. This instability is examined theoretically and is shown quantitatively to have a predictable electrohyd rodynamic origin. Furthermore, suspended particles are used to confirm the existence of unstable motion, and also to unambiguously determine the polar ity of ions associated with each mobility. Under subsequent zero bias, reco very of the solutions from nearly complete depletion is shown to originate at the solid surfaces of the test cell. (C) 1999 American Institute of Phys ics. [S0021-8979(99)08424-8].