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In this study, we prepared water-based nanofluids and tested their crystallization supercooling degree (SD) in two containers made of different materials. The test aimed to explore the comprehensive effects of nanoparticles and container properties on the crystallization SD of the nanofluids. In particular, we analyzed the effects of nanoparticle weight fraction, container surface roughness and wettability, and the cooling rate which was determined by container thermal conductivity, on the SD of the nanofluids. The main influencing factor among container properties on the SD of the nanofluids was determined, and the relative importance of the effects of nanoparticles and container properties with respect to SD was discussed. [ABSTRACT FROM AUTHOR]

Aqueous dispersions of Titania nanoparticles were cooled using differential scanning calorimetry (DSC). The nanoparticles reduce the supercooling of water by acceleration of nucleation. The experimental results demonstrated the important role in water crystallisation by the internal surface of the sample holder, and that stable nanofluids are required for the measurements to investigate the effect of nanoparticles on freezing. But for dispersions at low concentrations, such as 0.05 wt% and 0.1 wt%, the starting temperatures of freezing were found to be unusual at the cooling rates of 3°C/min and 4.5°C/min, namely they were even lower than that of the deionised (DI) water. It is found that surface controlled nucleation (SCN) is dominant at low cooling rates, while volumetric controlled nucleation (VCN) is dominant at high cooling rates. [ABSTRACT FROM PUBLISHER]

Highlights: [•] Effect of SDS on reducing supercooling degree of TiO2/H2O nanofluid is found. [•] The effect of SDS depends on SDS-to-TiO2 mass ratio and SDS concentration. [•] The greatest effect of SDS is achieved when SDS adsorbed on TiO2 reaches saturation. [Copyright &y& Elsevier]