Two series of cationic surfactants [(i) nC, H2m+,! nC, Hzn+ l) N+(CH3) 2X-with m= 12 or 16, n= 1-8, and X-= CI-or Br-;(11) nC, H2,+ l (C6H5 (CH2) p) N+(cH3) 2x-with m= 10, 12, 14, 16, and 18, p= 0-2, and X-= CI-or Br-] have been synthesized and used to prepare water in oil microemulsions, with various aromatic solvents. The water solubility in these microemulsions and the phase behavior of the systems when the water content slightly ...