Creation and characterization of thermal conductive foam using CNC and aluminum nitride.

Today`s technology is growing smaller and smaller, creating the need for small and efficient devices and materials for the expulsion of heat from electronic circuits in small spaces. One choice for such a material is a foam with high thermal conductivity and low electrical conductivity made from Cellulose Nanocrystals and Aluminum Nitride. Cellulose Nanocrystals are rod-like Nanoscaled particles with high mechanical and tensile strength, that can be extracted from one of nature`s most abundant biopolymers, Cellulose. These particles properties, such as large surface area and many functional groups. These properties in combination with its inexpensiveness make it a desirable material in this case, even though it does not have sufficient thermal conductivity by itself. In order to increase the thermal conductivity, a highly conductive material such as aluminum nitride can be introduced into the foam. Moreover, aluminum nitride has a high electric resistivity and contributes to the electric insulation of the composite. The goal is to create and to characterize a highly thermal conductive foam made from CNC and aluminum nitride that will allow for the transfer of heat in a single axis. This will be achieved by freezing a suspension of CNC and aluminum nitride that creates a cryo-concentration effect, in which the ice crystals that form push the CNC particles together and forcing them to aggregate locally to create a structure of layers in the resulting foam. These layers are what helps the heat transfer in a specific axis.