Electric-field-induced phase inversion in immiscible liquid blends of urethane-modified polypropylene glycol (UPPG)/dimethylsiloxane (DMS) was discovered. When the fraction of DMS is in the range of 23-26 wt. %, UPPG forms the particulate domains and DMS forms the continuous phase under no field. However, the application of an electric field induces connection among UPPG domains, and results in phase inversion; UPPG forms the continuous phase and DMS forms the particulate domains. This finding gives great possibilities of controlling the phase structure of blends using an electric field, and thus controlling their physical properties. (C) 1997 American Institute of Physics.