PROPERTIES OF NEW GLUCAMIDE SURFACTANTS

Properties of new nonionic surfactants are reported. The amphiphiles p ossess two 12-alkyl chains and two glucamide head-groups and have the formula (CnH2n+1)(2)C[CH2NHCO(CHOH)(4)CH2OH](2) with n = 5-9 (abbrevia ted here as di-(Cn-Glu)). For di-(C7-Glu) in the concentration range 0 .4-8%, an upper critical solution temperature (UCST) is observed; this is unusual behavior for a nonionic surfactant. Nonetheless these mate rials behave like classic surfactants with regard to changes in liquid crystal phases, surface tensions, and critical micelle concentrations (cmc's) as a function of chain length n. Small-angle neutron scatteri ng (SANS) data indicate the presence of anisotropic micelles, cylindri cal for di-(C5-, 6-, and 7-Glu) but discoidal for di-(C8-Glu). There i s apparently little effect of temperature (25-70 degrees C) on cmc or micelle structures.