ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We consider the three-liquid-phase, α, β, and γ, coexisting system water+n-tetradecane +diethylene glycol monohexyl ether and the densities of these three phases are in the order ρα〈ρβ〈ργ. An enhanced video pendant drop tensiometer is applied to measure the interfacial tensions to further reconfirm that a wetting transition occurs by the γ phase at the αβ interface upon approaching its lower critical end point. The mechanism of reappearance of suspended drops at the αβ interface is carefully observed by the enhanced video microscopy system. It is found that these suspended drops are made of the γ phase, and are formed by a very slow process of aggregation of very small drops. The contact angle θ spanned by the αγ and βγ interfaces of a γ phase suspended drop at the αβ interface is verified to be a quasiequilibrium property. In addition, the interfacial tension resulting from the profile of a suspended drop below the αβ interface is consistent with the tension of βγ interface σβγ by the pendant drop digitization method. A variety of wetting/nonwetting behaviors as well as wetting transitions is also discussed. It is found that there is a β phase wetting layer separating the air and the α phase. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.470892
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