Cluster and network formation toward percolation in the microemulsion L₂ phase formed by an amphiphilic triblock copolymer and water in p-xylene

Evidence is presented for cluster formation in the L₂ phase of systems with the triblock copolymer Pluronic L64, water, and p-xylene. The static and dynamic properties have been investigated by time-resolved fluorescence quenching, rheology, conductometry, and dynamic light scattering as a function of the temperature and water content. A network of connected swollen reversed micelles forms a percolation cluster at temperatures below 20 °C. Droplet linking, present over the whole temperature range investigated, occurs via the two hydrophilic amphiphile moieties. Interdroplet connections are favored as the solvent quality for the hydrophobic copolymer moiety becomes worse on decreasing the temperature.