Figure 8

(a) Spectral optical characteristics, and (b) hydrodynamic particle size distribution of the as-prepared and after heating (for 12 hours at 300 °C) nanofluid samples; and (c) spectral optical characteristics, and (d) hydrodynamic particle size distribution of the as-prepared and after heating (for 72 hours at 300 °C) nanofluid samples (5 ml/L); tested under airtight conditions.