Phase behaviour of alkyl glycerol ether surfactants

In this paper the phase behaviour and physical properties of a series of alkyl (C-6, C-8, C-12 and iso-C-8) monoglycerol ethers and 2-hydroxyalkyl (C-6, C-8, C-12) monoglycerol ethers are presented. The binary phase diagram for the surfactants shows very little dependence on temperature. Ir can be seen that as the alkyl chain length increases the tendency to form lamellar liquid crystalline phases increases. The branched alkyl chain shows no formation of lamellar phases even at high concentrations of surfactant. The difference in phase behaviour between the surfactants is attributed to the variation in the critical packing parameter (CPP) of the surfactants. The presence of an additional hydroxyl group in the alkyl chain causes temperature-independent solubility behaviour. Ternary phase diagrams were prepared using dodecane as the oil phase. Hexyl glycerol ether was the only one of the alkyl glycerol ethers that was sufficiently water-soluble to determine the surface tension and c. m. c. The c. m. c. was determined as 15 mM (and surface tension as 26 mN m(-1)).