纳米颗粒悬浮液稳定性分析

Stability of Nano-particle Suspensions

讨论纳米颗粒悬浮液的稳定性问题.对不同颗粒、不同基液制备的悬浮液稳定性进行了实验研究,在此基础上,探讨颗粒与基液的密度、颗粒的等效直径、基液动力粘度等因素对悬浮液稳定性的影响.结果表明:颗粒等效直径与基液动力粘度对悬浮液的稳定有决定性作用.

Due to the increasing development of nanotechnology and its practical applications, the thermal conductivity of a nanoparticle suspension is becoming a frontier of nanofluid and its application in enhancing heat transfer. It is highly expected that the addition of nanoparticles can significantly enhance the conductivity of the liquid without clogging, erosion, sedimentation and increase in pressure drop, which usually are encountered in common particle suspensions. However, the stability of nanoparticle suspension is not still as good as expected in practical experiments. Available investigations indicate that the stability can be improved choosing proper combination of nanoparticle and base fluid. In this paper, a series of experimental investigations are conducted to observe the stability of nanoparticle suspensions with different combinations of nanoparticles and base fluids. Experimental evidences demonstrate the influence of particle geometrical and physical properties, fluid properties, particularly viscosity on the stability. The most important factors for the stability of nanoparticle suspensions are effective diameter of nanoparticle cluster and viscosity of base fluids. Decreasing the effective diameter of nanoparticle cluster and increasing the viscosity of base fluids can significantly increase the stability of nanoparticle suspension.