A THEORY OF AQUEOUS EMULSIONS .I. NEGATIVE INTERFACIAL TENSION AT OIL/WATER INTERFACE
A THEORY OF AQUEOUS EMULSIONS .I. NEGATIVE INTERFACIAL TENSION AT OIL/WATER INTERFACE
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DOI：
10.1016/0021-9797(67)90099-9
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发表时间：
1967-01-01
影响因子：
9.9
通讯作者：
PRINCE, LM
中科院分区：
文献类型：
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作者：
PRINCE, LM
提出了高膜压引起的负界面张力是微乳液形成的原因。现在看来，肥皂和长链醇混合膜的初始负界面张力γ φ与其说是高初始膜压力π G ā的结果，不如说是水和油相及其吸附的醇单层之间界面张力（γ o/w） a的大下降的结果，其公式为γ φ（γ o/w） aπ。这种下降是由于醇在界面和油相之间的自发分布造成的。指出这种分布取决于给定油中特定醇的初始化学势，并且可以在很宽的范围内变化。残留在油相中醇的部分可用于降低油/水界面张力，而其余部分则与水相中吸附的乳化剂形成混合膜。在薄膜的头和尾之间，库仑力、氢键力和范德华力的相互作用在平面界面上形成初始压力梯度，产生初始膜压力π G。假定压力发展有三个阶段，最大压力对应于酒精的中等浓度。以（γ o/w） a和π G´为纵坐标，以酒精浓度为横坐标的假设图提供了微乳化过程的图形表征。
It was proposed that negative interfacial tension due to high film pressure is responsible for the formation of micro emulsions. It now appears that the initial, negative interfacial tension γ φ in mixed films of soap and long-chain alcohols is the result not so much of a high initial film pressure π G ̄ as of a large depression of the interfacial tension (γ o/w) a between the water and the oil phase with its adsorbed alcohol monolayer in accordance with the equation γ φ(γ o/w) a π. This depression is brought about by the spontaneous distribution of alcohol between the interface and the oil phase. It is pointed out that this distribution is dependent upon the initial chemical potential of the particular alcohol in the given oil and that it may vary within wide limits. The fraction of the alcohol that remains in the oil phase is available to depress the oil/water interfacial tension while the remainder of it forms a mixed film with emulsifier adsorbed from the water phase. It is submitted that the interaction of coulombic, hydrogen bonding and van der Waals forces among the heads and tails of the tenants of this film develops an initial pressure gradient across the flat interface which generates the initial film pressure π G ̄. Three stages of pressure development are postulated, the maximum pressure corresponding to an intermediate concentration of alcohol. Hypothetical plots of (γ o/w) a and π G ̄ as ordinates versus concentration of alcohol as abscissa provide a graphical characterization of the process of microemulsification.