The phase behavior of the palm-kernel oil / glycerine / tween / water four-component system is represented in a pseudo-ternary phase diagram. The influences of surfactants (tween20, tween40, tween60, tween80 and tween85) and mass ratio of co-surfactant to surfactant (km) on the microemulsification region of the systems are discussed. Results show that the maximum area of microemulsion region is achieved using tween-60 as surfactant with the km value being of 0.5.
