The FTIR spectral analysis did not prove generation of chemical products during crystallization process of the Composite 3, but two peaks on DSC solidification curve of the Composite 3 (Fig.1) would suggest that the inhomogeneous structure was formed during crystallization process. Additionally the DSC curve of the Composite 2 (Fig.1) showed bigger temperature hysteresis of 4 degrees, while the subcooling is of 3 degrees. DSC results merely defined needs of more detailed further research and analysis of the composite structure. Next correlation between thermal and structural properties initiated observations of inhomogeneous fragments of the novel salt/graphite composites structures, well exemplified with SEM images below. (Table 3.).

The inhomogeneous composite structure shows inhomogeneous salt crystal distribution, salt/graphite clustering, untypical salt crystal formation caused by uncontrolled nucleation frequency and crystallization growth rates of the NaNo3/KNO3eutectics — important factors responsible for structural stability of the composite

Table 3. Inhomogeneous structural fragments of NaNO3/KNO3eutectics/graphite composites.