| 초록 |
The intermediate phase(s), which may be important in detergency and otherapplications, sometimes forms immediately upon contact and sometimes later,depending on the compositions and relative volumes of the initial fluids.1-4 Becausevariations of soil composition with time during the washing process is an importantfactor in these systems, a new technique has been utilized in which observations aremade of a single oil drop brought into contact with a much larger volume ofsurfactant solution.5-8 With this technique, it was found that the lamellar liquidcrystalline phase began to form at various times after contact when drops of pureoleyl alcohol5 or of mixtures of oleyl alcohol with n-hexadecane7 were injected dilutesolutions of pure linear ethoxylated alcohol. A quasi-steady-state analysis wasdeveloped which yielded predictions in agreement with experimental results on howthe time until initiation of liquid crystal formation varied with initial drop diameterand bulk surfactant concentration in the aqueous phase. In this paper, results of similar contacting experiments for systems containingamine oxide surfactants and shorter chain alcohols which have appreciable solubilityin water are presented. Alcohol diffusion into the aqueous phase can cause the dropto shrink until intermediate phase formation begins instead of to grow as in the oleylalcohol systems.4,7 Dynamic behavior observed using videomicroscopy could beexplained in terms of the equilibrium phase diagrams constructed for this system anda quasi-steady-state diffusion model which is generalized version of the onedeveloped previously.
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