Quaternary cross-diffusion in water-in-oil microemulsions loaded with a component of the belousov-zhabotinsky reaction

We obtain the diffusion matrix, D, consisting of the main and cross-diffusion coefficients for a loaded AOT microemulsion, a quaternary system containing water (1)/AOT (2)/species (3)/octane (4). Here “species” is a component of the Belousov−Zhabotinsky reaction: NaBr, NaBrO3, bathoferroin, ferroin, or Br2. The main and cross-diffusion coefficients of each species depend crucially on its solubility. For water-soluble species (the salts), D13 and D23 are large (much larger than the main diffusion coefficients) and positive. For species located mainly in the surfactant shell (bathoferroin or ferroin), D13 and D23 are large and negative. For oil-soluble Br2, D13 and D23 are larger and more negative, whereas D33 ≫ D11, D22. The coefficients D31 and D32 are small for all species studied.