Numerical analysis for the effects of particle distribution and particle size on effective thermal conductivity of hybrid-filler polymer composites

Abstract

This study describes the thermal conductivity (TC) enhancement of polymer composites with randomly distributed hybrid fillers using both numerical and theoretical approaches. The effective thermal conductivity (ETC) of such composites is examined as a function of the TC ratios, volume fraction (VF), and particularly particle distribution and particle size. Effects of particle distribution were first explained comprehensively with combination of both numerical and theoretical analyses. Analyzed results show that particle distribution and particle size become important and affect significantly to the maximum ETC at high VF, high TC, and large size of hybrid fillers. However, the optimal TC ratio between two fillers is shown to be unaffected by both particle distribution and particle size. Particularly, the TC is generally enhanced when more particles are stacked and concentrated along the thermal flow direction. These results are very good in practical optimization process to achieve the maximum ETC of composites, thus total cost of composite synthesis can be reduced significantly.