To understand the stability mechanism of emulsion liquid membrane system (ELMs) which was prepared by using Span 80(Sorbitan oleate) as emulsifier ,the dilational viscoelasticity of oil/water interfacial film of Span 80‐decane‐D2EHPA‐H2O ELMs (D2 EHPA = di(2‐ethylhexly)phosphoric acid) were studied by means of oscillating barriers method .The major effect fac‐tors such as perturbation frequency ,Span 80 concentration ,temperature and D2 EHPA on dilational viscoelasticity were also in‐vestigated .Meanwhile ,the stability of Span 80‐decane‐H2 O emulsion was detected by using Turbiscan?LAB instrument based on the principle of multiple light scattering ,and the relationship between dilational viscoelasticity and emulsionstability was also discussed .The results show that the interface film (i .e .Span 80 monolayer) of emulsion system is an elastic membrane ,and its dilational elasticity εrvalue increases with the increasing of perturbation frequency and Span 80 concentration ,but decreases with the increasing of temperature .The competitive adsorption between D2 EHPA and Span 80 at decane/H2 O interface results in a de‐creases of εrvalue .The greater theεr value ,the better the stability of emulsion ,and higher Span 80 concentration and lower tem‐perature are helpful to increase εr ,thus to improve the stability of the emulsion .%为探讨以Span 80（失水山梨醇单油酸酯）为乳化剂所制备的乳化液膜体系的稳定机理，采用小幅低频振荡法考察了扰动频率、Span 80浓度、温度、萃取剂D2EHPA（二‐（2‐乙基己基）磷酸）对Span 80‐癸烷‐D2EHPA‐H2O液膜体系油／水界面膜扩张黏弹性的影响，同时利用基于光散射原理的TURBISCAN Lab expert型稳定性仪测定了乳液的稳定性，讨论了界面膜扩张黏弹性与乳液稳定性的关系。研究结果表明：Span 80‐癸烷‐H2 O乳液的界面膜（即Span 80单分子膜）是一种弹性膜，其弹性模量εr随着扰动频率的增大而增大，随Span 80浓度的增大而增大，但随温度的升高而减小；D2 EHPA在癸烷／H2 O界面与Span 80的竞争吸附使界面膜的εr减小。界面膜的εr 越大，乳液体系就越稳定，反之亦然，较高的Span80浓度和较低的温度有利于增大界面膜的εr，因此有利于提高乳液体系的稳定性。
展开▼
