New anhydrous aluminum nitride dispersions as potential heat-transferring media

Aluminum nitride was found to be of great significance in advanced ceramics. A widely applicable semiconductor, AlN is also commonly known for its considerable heat conductivity, as high as 320 W/(m·K). The idea behind the studies was to use AlN dispersions as a heat transferring liquid in closed systems. Such a liquid heat-carrier should give a proper rheological response when under variable shear-temperature conditions. Contrary to other systems reported in literature, i.e. nanofluids [1–20], the systems presented consisted of AlN micropowder and some novel base liquids: poly(propylene glycols) with an average molecular weight of 425 and 2000. The optimal result was to produce dispersions which display Newtonian-like flow at increased temperature and shear rate, as well as a suitable AlN concentration with sustained time-stability. This compilation of research assumptions should result in intensified heat exchange capabilities of liquid transferring media made on the basis of aluminum nitride.