Category: Transient Plane Source
Abstract: The addition of thermally conductive nanoparticles to conventional heat transfer fluids enhances their performance so they can be used for high-powered applications. However, as nanoparticles are added, the liquid becomes more viscous, which decreases thermal conductivity. Changing the pH of the solution can control the clustering of nanoparticles to maintain and even enhance thermal conductivity. This study used the transient plane source (TPS) method to measure the thermal conductivity of a Cu-H2O nanofluid over a range of pH levels. The nanofluids were each measured at 0.02 Volt for 5 seconds at 25 °C, with 10 replicates for each sample. Results showed that the thermal conductivity of the solution increased with the pH and peaked at a basicity slightly above neutral. This is because there are more surface charges at a higher pH, which stabilizes the particles and increases thermal conductivity. With this knowledge, the thermal conductivity of nanofluids can be further enhanced by manipulating pH in future studies.
Reference: Thammasat International Journal of Science and Technology, 16, 4 (2011) 65-72