2010 年 27 巻 4 号 p. 347-354
Phase change emulsion (PCE) is a novel fluid used for heat storage and transfer. It has the following characteristics: higher apparent specific heat and higher heat transfer ability in the phase-change temperature range as compared to the conventional single-phase heat transfer fluids. In particular, oil-in-water (O/W) emulsions are latent heat storage materials that have low melting points, thus offering attractive opportunities for heat transfer enhancement and thermal energy transportation and storage. In this paper, milky white oil-in-water emulsions have been formed using water, Tween 80, Span 80, and tetradecane by low-energy emulsification methods (e.g., the phase inversion temperature (PIT) method). The relations between the component ratios of the emulsions and both the particle diameters and the stability of the resulting emulsions have been determined by dynamic light scattering (DLS) and vibration viscometry. The results show that the apparent viscosity of the nanoemulsion is lower than that of an emulsion, which was prepared with the same mixing ratio of surfactant and concentration of phase change material. Moreover, the surfactant concentration is found to contribute to the stability of the phase change nanoemulsion. Results indicate that the phase change nanoemulsion is a promising material for thermal storage applications.