MECHANISM OF TRANSPORT OF CHARGE-CARRIERS IN THE SODIUM BIS(2-ETHYLHEXYL) SULFOSUCCINATE-WATER-DECANE MICROEMULSION NEAR THE PERCOLATION TEMPERATURE THRESHOLD
Y. Feldman et al., MECHANISM OF TRANSPORT OF CHARGE-CARRIERS IN THE SODIUM BIS(2-ETHYLHEXYL) SULFOSUCCINATE-WATER-DECANE MICROEMULSION NEAR THE PERCOLATION TEMPERATURE THRESHOLD, Journal of physical chemistry, 100(9), 1996, pp. 3745-3748
The transport properties near the percolation temperature threshold in
the ternary water-in-oil microemulsion stabilized by ionic surfactant
has been studied by measuring the self-diffusion coefficients of all
the constituents of the microemulsion, and the conductivity for temper
atures between 10 and 40 degrees C. It can be conjectured that two dif
ferent transition mechanisms of the charge carriers in this temperatur
e region may take place. These may be attributed to either the transfe
r of counterions from one droplet to another through water channels or
hopping of surfactant ions from droplets within clusters. The results
support the hypothesis that the conductivity and dielectric polarizat
ion below the percolation threshold is mainly due to the motion of cou
nterions via water channels within the droplet clusters and not a char
ge-hopping mechanism at the surfactant interface. Above the percolatio
n threshold the latter mechanism also appears, connected with migratio
n of surfactant molecules from droplet to droplet within a percolation
cluster. The first mechanism, however, still dominantes.