It was found that Pickering-type persistent multiple emulsions would be generated by one step method through mixing aqueous Laponite particle dispersion diluted with water before emulsification and oil solution containg Span80. The effect of Span80 concentration, Laponite concentration and water ratio on the stability of emulsions was studied. The formation and mechanism of Pickering-type persistent multiple emulsions by one step method were discussed. The experimental results showed that the dilution of Laponite particle suspension was the key factor of generating Pickering-type persistent multiple emulsions. The water ratio determined the inner water drop volume. With the increase of Span80 concentration, mean diameter of multiple emulsions decreased while stability increased greatly. Concentration of Laponite particles could impact the style of emulsions, but had little influence on the stability and diameter of emulsions. The lower diffusion rate of Laponite particles in water disperse system is the main reason of forming Pickering-type persistent multiple emulsions by one step method.

Key words: multiple emulsions, one step method, Laponite, Span80