Phase transitions in colloidal dispersions in a liquid crystalline medium

We present experimental studies on colloidal suspensions in a lyotropic sys tem exhibiting an isotropicnematic-lamellar phase sequence upon decreasing the temperature. The particles are found to undergo a gas-liquid transition in the nematic phase of the suspending medium, indicating the existence of an attractive interparticle interaction. The resulting liquid phase is wea kly anisotropic. Further, the nematic-lamellar transition of the liquid cry stal is found to be accompanied by a liquid-solid transition of the particl es.