材料期刊网

It has been shown that optical activity can occur in microemulsion under external electric field and rotation angle can also be tuned by the electric field. A set of microemulsions (water/Span80/transformer oil) with different water concentration were prepared and their optical activity was measured with the changes of applied electric field and theta, the angle between the electric vector of the incident linearly polarized light and the external electric field, using an automatic polarimeter. The experiments indicate that when none of the external electric field, water concentration and phi are zero, there is optical activity in microemulsions. For a given concentration, rotation angle psi increases with electric field, and it firstly increases, passes through a maximum at C = C-0, then monotonically decreases as C increases when electric field keeps constant. The relationship between the rotation angle and phi is also obtained. It is thought that the electric field-induced destroy of spatial symmetry of microemulsion is responsible for the optical activity of microemulsion.