Abstract: The stable oil-in-water miniemulsion were prepared using mixed emulsifier comprising a mixture of ionic surfactants (quaternaryammonium compounds) and long chain fatty alcohols (C₈ to C₁₆) in low concentration. The chain length of the fatty alcohols, mole ratio of surfactant to fatty alcohol appeared an important factor influencing the formation of miniemulsions. The temperature of emulsification, property of oil phase and volume fraction of internal phase also affected the oil droplet size and the stability of the emulsion. The stabilization of emulsions has been interpreted in terms of the formation of the lyotropic liquid crystals.

Key words: miniemulsion, long chain fatty alcohol, lyotropic liquid crystal