Physicochemical Studies on Microemulsions. 7. Dynamics of Percolation and Energetics of Clustering in Water/AOT/Isooctane and Water/AOT/Decane w/o Microemulsions in Presence of Hydrotopes (Sodium Salicylate, α-Naphthol, β-Naphthol, Resorcinol, Catechol, Hydroquinone, Pyrogallol and Urea) and Bile Salt (Sodium Cholate)

The temperature induced percolation of w/o microemulsions (water/AOT/isooctane and water/AOT/decane) has been studied at different [water]/[AOT] mole ratios (ω), and in the presence of hydrotopes (sodium salicylate, α-naphthol, β-naphthol, resorcinol, catechol, hydroquinone, pyrogallol, urea) and the bile salt sodium cholate. The results have been analyzed to quantify the threshold percolation temperature, performance of the Scaling equation, the activation energy for the percolation process, and the thermodynamics of the clustering of the dispersed nanodroplets. The influence of temperature and additives on the droplet dimension, the polydispersity, and the diffusion coefficient has been also investigated by the DLS studies. An attempt has been made to correlate the results with the differential activities of the hydrotopes. A possible mechanism of the varied activities of the hydrotopes is proposed.