An innovative PDMS cell to improve the thermal conductivity measurements of nanofluids

The traditional methods to measure the thermal conductivity of nanofluids (NFs) do not allow the investigation of critical features that affect the NF's heat transfer performance. For instance, during the thermal conductivity measurements, the NF's thermal properties may be subject to several critical features such as sedimentation, aggregation and wall adhesion of NPs. In addition, the measurement cell has severe functional limitations in terms of full cleaning and performing direct visualizations due mainly to design, geometrical and material constraints. These are frequent problems encountered at the transient hot-wire and transient plane source (TPS) methods, two popular techniques often used to measure NF's thermal conductivity. In this way, polydimethylsiloxane (PDMS), due to its unique properties, such as thermal stability and excellent optical transparency, was applied to fabricate an innovative and simple cell that offers a more straightforward and efficient way to clean the NPs deposited on the walls and as a result to avoid any possible sample contaminations.