The interactions between PC vesicles and the air/water and oil/water interfaces

Abstract

The interactions between egg phosphatidylcholine (EPC) vesicles (diameter 200 nm) and flat surfaces (air/water and types of oil/water) were investigated by measuring the change in interfacial tension after adding PC vesicles to bulk NaCl or MgCl 2 aqueous solutions. Electrostatic potential and Van der Waals potential curves were applied to analyze the effects of salt concentration and the influence of different oil interfaces on changes in interfacial tension. The experimental results show that the electrostatic interaction between vesicle and the interface agrees with the constant surface charge model. The largest decrease in interfacial tension was observed with a 10 −3 M MgCl 2 concentration. The larger the Hamaker constant ( A 132), the greater the change in interfacial tension change observed.