Phase Behavior of Nonaqueous Microemulsions of n‐Methyl‐2‐Pyrrolidinone/Diisooctylsodium Sulfosuccinate (AOT)/Alkanes

Abstract

The phase behavior of n-methyl-2-pyrrolidinone (NMP) microemulsions formed by the combination of NMP and oils (hexane, heptane, octane, and isooctane) in the presence of diisooctylsodium sulfosuccinate (AOT) were studied. The ternary plots were constructed and found to be similar in nature and consisted of a gel, a clear, or microemulsion, and a two phase region. Effects of varying amounts of water added to NMP and varying the chain length of n-alkane (as oil) on the microemulsion region were investigated. Fluorescence probes such as Auramine-O and the sodium salt of aniline-1-napthalenesulfonic acid were employed to investigate the nature of the microemulsion region. Volume and temperature induced percolation studies have indicated the absence of percolation process in these microemulsion systems.