PHASE-BEHAVIOR 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-hydrox yalkyl (C-6, C-8, C-12) monoglycerol ethers are presented. The binary phase diagram for the surfactants shows very little dependence on temp erature. Ir can be seen that as the alkyl chain length increases the t endency to form lamellar liquid crystalline phases increases. The bran ched alkyl chain shows no formation of lamellar phases even at high co ncentrations 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 hyd roxyl group in the alkyl chain causes temperature-independent solubili ty behaviour. Ternary phase diagrams were prepared using dodecane as t he oil phase. Hexyl glycerol ether was the only one of the alkyl glyce rol ethers that was sufficiently water-soluble to determine the surfac e tension and c. m. c. The c. m. c. was determined as 15 mM (and surfa ce tension as 26 mN m(-1)).