ELECTRIC-CONDUCTIVITY NEAR THE PERCOLATION TRANSITION OF A NONIONIC WATER-IN-OIL MICROEMULSION

The electric conductivity of a nonionic water-in-oil microemulsion has been measured in the presence of small amounts of carrier electrolyte . Two distinct regimes can be distinguished: the conductivity increase s linearly for small nanodroplet concentration, while it decreases abo ve a critical value. The qualitative change occurs close to a concentr ation where the system is known to have formed a system-spanning nonco nducting cluster of nanodroplets. This behaviour of the conductivity i s shown to agree well with predictions of percolation theory for aggre gating charged nanodroplets.