Isothermal Switching of conductivity in microemulsions via photodimerization of acridizinium bromide [1]

Abstract
Microemulsions composed of Aerosol OT (AOT), isooctane, and water in the mass ratio 1:1. 54:0.75 exhibit percolation, i.e., transition from a w/o to an o/w microemulsion, at 33 °C as revealed by the appearance of conductivity. In the presence of 0.01 mol/dm3 of acridizinium bromide the percolation temperature increases to 38 °C. Irradiation of this mixture with glass‐filtered light leads to a further rise of the percolation temperature to 43 °C. Thus, the system can be switched from conducting to non‐conducting upon irradiation at between 38 and 43 °C.