Light induced switching of conductivity in AOTisooctanewater microemulsions via photoreactions of solubilizates

Small amounts of solubilized N-methyldiphenylamine or 9-hydroxymethylanthracene and their photoproducts (N-methylcarbazole and photodimers of 9-hydroxymethylanthracene, respectively) had specific influences on the percolation temperature (as revealed by the onset of conductivity) in monophasic microemulsions composed of AOT, isooctane, and water: both the solubilizates induce shifts of the temperature at which conductivity sets on and affect the temperature of the border to the upper two phase region, 9-hydroxymethylanthracene being more effective. UV-irradiation in both cases lead to a decrease of the percolation temperature by several degrees. Therefore conductivity (percolation) can be switched isothermally from zero up to 3 mS cm−1 upon exposure of samples to UV light.