Improving the efficiency and recognizability of the spectroscopy method for measuring nanofluid stability

This study proposed a method to improve the efficiency and recognizability of the spectroscopy method for measuring nanofluid stability. The 0.2 wt% and 0.4 wt% carbon-based nanofluids (CBNFs) were used as samples. The volumes of three test types of samples in the cuvette were 2.5 mL (Case 1), 1.8 mL (Case 2), and 1.8 mL (Case 3), respectively. In addition, an opaque black tape covered the lower half of the original area spotted by the probe beam in Case 3. The spectrometer was used to measure absorbance at wavelengths of 400–800 nm at fixed time interval. The results indicate that reducing the distance between the area spotted by the probe beam and the liquid level can improve the efficiency and recognizability of CBNF stability detection. For the optimal condition, the time to detect CBNF settling reduces by 50% and recognizability improves by 34.9% in the design of Case 2.