Interactions between polar and non-polar surfaces in triglyceride oil

摘要

The forces acting between polar and non-polar surfaces immersed in a triglyceride oil,triolein,have been determined as a function of surface separation employing a surface force apparatus.It was found that the polarity of the surfaces has a large effect on the interactions.The water activity of he sample influences the interactions between polar surfaces significantly.Close to water saturation,a capillary condensate is formed between two such surfaces,when they are less than 100 A apart.On the other hand,water activity has a rather minor effect on the interactions between non-polar surfaces. It was found that L- alpha - oleylpalmitoylphosphatidylethanolamine (OPPE) adsorbs in monolayers on mica,but in much larger amounts on sucrose.We discuss this finding in terms of capillary condensation of an OPPE rich phase.The effects of added OPPE on the interactions between mica surfaces in triolein were also explored.