Rheological behaviors of sugar alcohols for low-to-medium temperature latent heat storage: Effects of temperature in both the molten and supercooled liquid states

As potential candidates of solid - liquid phase change materials (PCM) for latent heat storage in the low-to-medium temperature range (80-250 degrees C), the temperature-dependent Theological behaviors of five select sugar alcohols were characterized over a wide range of shear rates from 10(-3) s(-1 )to 10(4) s(-1). It was found that the four linear-structured sugar alcohols, i.e., xylitol, erythritol, d-mannitol, and d-dulcitol, are Newtonian fluids above their respective critical shear rates, in both the molten and supercooled liquid states, and that they exhibit typical shear thinning behaviors below the critical shear rates. In particular, d-mannitol and d-dulcitol, with relatively higher melting points, behave like Herschel-Bulkley fluids, which experience slight yield under small yield stresses (0.0001-0.0099 Pa s and 0.0078-0.0528 Pa s for d-mannitol and d-dulcitol, respectively). Inositol, the only cyclic-structured sugar alcohol with the highest melting point (497.65 K), also behaves like a Herschel-Bulkley fluid in both the molten and supercooled liquid states. The dynamic viscosity curves of inositol were found to agree with the Cross model, leading to determination on its zero shear and infinite shear viscosities. An Arrhenius-type dynamic viscosity-temperature curve was observed for inositol over the entire temperature range at the highest shear rate of 10(4) s(-1).