AIN Nanopowder

The plasma chemical method is relatively often used now for preparing many nanopowders for production of refractory compounds (nitrides, oxides, carboni-trides, and their compositions) [6]. The process of preparing aluminum nitride nanopowder by this technique is based on evaporation of aluminum in high temperature nitrogen flow, following chemical interaction, and subsequent condensation of reaction product. It means that this process could be considered as a kind of combustion synthesis. 

The product of interaction of aluminum with nitrogen is gray powder with nitrogen content up to 32 wt%. Particles have shape of needles or balls and, according the results of chemical and X-ray diffraction (XRD) analysis, the powder contains traces of metallic aluminum. Such morphology of powder particles suggests that the nitride particles grow from liquid phase (probably liquid aluminum particles). 

The plasma technique allows also production of nanosized nitride powder doped with sintering additives, for example, aluminum nitride doped with yttria. Such composite powders are characterized with high degree of homogeneity because the formation of powder particles occurs by simultaneous condensation from gaseous-vapor phase [13]. 

Specific surface area of powder (m g ) Oxygen content (in wt%) of  

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The possibility of using aluminum nitride (AIN) nanopowders as flame retardant additive was studied [25]. Concentration of the nanopowder AIN incorporated in a polyethylene matrix was 0.1 0.25 0.75 1.5 and 3 wt%. The incorporation of 1.5 wt% AIN in a polyethylene matrix caused the significant increase in the temperature of the beginning of oxidation of 33 °C (to 183 °C) in comparison with pure polyethylene (150 °C) and in the onset temperature of the intensive weight loss of 15 °C (to 375 °C) against 360 °C for pure polyethylene. The resulting effect is explained by the influence of nanoparticles on the microstructural characteristics of polyethylene. Nanoparticles are the crystallization centers and participate in the formation of fine-grained structure. 

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