Phase behaviours and conductivity study of water/CPC/alkan-1-ol (C-4 and C-5)/1-hexane water/oil microemulsions with reference to their structure andrelated thermodynamics

The microemulsion forming systems of water/cetylpyridinium chloride/butan-1 -ol/n-hexane, and water/cetylpyridinium chloride/pentan-1-ol/n-hexane have been studied with respect to their phase behaviours and percolation of cond uctance to derive information on their droplet physicochemical characterist ics (dimension, interfacial area and composition, and number density). This was carried out at different water contents at specific ratios of surfacta nt and cosurfactant and at various temperatures. From the information colle cted, the energetics of the transfer of the alkanol (butan-1-ol and pentan- 1-ol) from the continuous oil-phase to the interfacial region (the interpha se) have been estimated. At the conductance percolation threshold, the drop lets cluster or associate, can be considered to form a pseudophase similar to surfactants forming micelles. Based on this concept, the energetics of t he clustering process have been evaluated, and the results are discussed in comparison with other recently studied systems.