Dynamics in water-AOT-n-decane microemulsions with poly(ethylene glycol) probed by dielectric spectroscopy

Aggregate Structure and Dynamic Percolation in Microemulsions

“…Dependency of the scaling parameters μ and s on the system parameters φ and W of a water/AOT/decane microemulsion [54] not independent of the detailed composition of the microemulsions (Fig. 2.19).…”

“…Nevertheless a finite dc conductivity in the order of σ 0 ≈ 10 −8 S cm −1 [54] can be measured, though the conductivity of the oil vanishes. The explanation is that single droplets can carry a net charge and by collisions a mass and charge exchange happens.…”

“…2.14) is quite unique and the percolation loci are given in coordinates of (φ p , T p ) usually determined by the inflexion point of the logarithmic conductivity. Additionally to the percolation transition the critical phase separation temperature T c or critical concentration can be determined by conductivity measurements marked by a drop in the conductivity [54]. As an example for the determination of the phase boundary, the phase separation temperature T c is shown in the right Fig.…”

“…To get access to a quantity describing the interfacial undulations a variation of droplet core radius R c has to [66,67]. Based on this considerations Meier predicted the following relation between the percolation temperature T P and the droplet radius [54,68]:…”

“…In contrast to a static system where the charge carriers can only move along a formed cluster, in a dynamic system charge carriers can additionally be moved by lattice point motion. So even below the percolation threshold a finite conductivity due to lattice point motion arises [54,56]. To incorporate the dynamic aspects into the percolation model two different jump rates have to be introduced [56].…”