Partially miscible binary liquids containing silica colloids show equilibrium phase boundaries and critical lines. The phase separation is ternary in nature, and measurements allow construction of the ternary phase prism for colloids dispersed in binary fluid mixtures. Comparison with earlier aggregation studies strongly suggests that the aggregation phenomena observed for colloidal particles in binary liquid mixtures is in fact a true phase separation in the ternary mixture.

• Received 19 July 1996

DOI:https://doi.org/10.1103/PhysRevLett.78.1379