MICROSTRUCTURE IN N-ALKANE-WATER-ELECTROLYTE MIXTURES WITH SMALL ETHOXYLATED ALCOHOL AMPHIPHILES

The ability of an amphiphilic molecule to form topologically ordered, surfactant-like aggregates is probed by studying the ethoxylated alcohols 3-oxaheptanol (C//4E//1) and 3,6-dioxadodecanol (C//6E//2). Density, refractive index, and NMR measurements indicated C//4E//1-water-(NaCl salt) solutions are ideal dilute solutions with no solute association up to a C//4E//1 mole fraction of about 0. 018 (ca. 11wt%). Above this concentration, the amphiphile forms aggregates which appear to be at least weakly cooperative. From the magnitude of the chemical shifts observed, C//6E//2 appeared to be more oriented than C//4E//1. Hence, even with these simplest ethoxylated alcohols, there are indications of surfactant-like aggregation, i. e. , topological ordering, between oil and brine domains.