Binary phase-change materials (PCM) used for thermal energy storage, with two phase transition temperatures or with solid nanoparticles, hold promise for improving transient performance as compared to single component materials. In these systems, small solid particles in the liquid phase are subject to thermal gradients during heat transmission. As a result, there is potential for particle migration due to thermophoresis. The impact of concentration gradient, temperature gradient, radius of nano particles and the solvent is analyzed. A mathematical model showed that thermophoresis will dominate the particle migration and there is a possibility of the development of non-uniformity in the dispersed particle in the system.