Viscosity and thermal conductivity characteristics of microencapsulated phase change material suspensions added with nano-particles

Nano-particles TiO₂ is introduced to suspensions micro-encapsulated phase change materials (MPCM). Thermal conductivity and viscosity of this kind of novel suspensions are investigated experimentally using rheometers and thermal property meters. It's revealed that when the mass concentration of the nano-particles is less than 5%, MPCM suspensions of 10% show non-Newtonian characteristics under low shear rates. Under high shear rates, however, the suspension could be considered to be a Newtonian fluid. The viscosity of the MPCM suspensions increases as the concentration of nano-particles increases. Viscosity increment of the MPCM suspensions is about 23% when the mass concentration of the nano-particles is 5%. Thermal conductivity increment of the MPCM suspension is about 7.3% when the mass concentration of the nano-particles is 5%.