Thermal conductivity improvement of electrically nonconducting composite materials

In this review, we summarize the latest studies on thermal conductivity (TC) of composite materials. TC enhancement of composite materials has been manipulated by using fi llers of different properties: material type, size, geometries, and functionalization. Examples of fi ller size ranges are nanoparticles (1 - 100 nm) and microparticles ( < 100 nm); fi ller geometries could be tubes or sheets, whereas fi ller materials could be carbon or boron nitride, which will be the focus of this review. It has been found that hybrid composite materials, i.e., systems containing more than one type of fi ller, such as a blend of nanosize and microsize fi llers, give better TC than any of these individual fi llers. Besides the fi ller intrinsic properties, its concentration, dispersion quality, and the preparation method of the composite affects the composite properties as well. The challenge is to optimize these parameters with the desired fi nal performances.