Effects of inclusion size on thermal conductivity and rheological behavior of ethylene glycol-based suspensions containing silver nanowires with various specific surface areas

This work is concerned with the size effects of Ag nanowires on thermal conductivity and rheological behavior of EG-based suspensions. The influences of inclusion concentration and temperature on the thermophysical properties of specimens containing three types of Ag nanowires were also investigated. It was shown that the measured thermal conductivity of EG-based suspensions increased with the rising temperature and loading. Besides, the relative enhancement in thermal conductivity exhibited a linear relationship with respect to the specific surface area of Ag nanowires. A theoretical approach was developed to predict the effective thermal conductivity of suspensions containing nanowires by introducing liquid layer into account. The Ag nanowires/EG interface thermal resistances were extracted from the experimental results, which ranged from 2.0 × 108 to 5 × 108 m2 K/W. Furthermore, a comparative study revealed the excellent performance of Ag nanowires used in present work on improving thermal conductivity compared with the reported studies. Finally, the presence of Ag nanowires with the highest aspect ratio (250) was concluded as the main explanation of a noticeable rise in dynamic viscosity and non-Brownian fluid behavior of EG-based suspensions at the highest loading (10 mg/mL).