Thermodynamics Research Center / ThermoML | Thermochimica Acta

Characterization of thermal performance of a solid solid phase change material, di-n-hexylammonium bromide, for potential integration in building materials

Whitman, C. A.[Catherine A.], Johnson, M. B.[Michel B.], White, M. A.[Mary Anne]
Thermochim. Acta 2012, 531, 54-9
ABSTRACT
Di-n-hexylammonium bromide ((n-C6H13)2NH2Br) undergoes a solid.solid phase transition at about 20 .C. The fact that it remains as a solid phase, yet the transition has a rather large enthalpy change (85 J g.1) suggests possible advantages as a phase change material (PCM) for integration into building materials. We investigated the phase change of (n-C6H13)2NH2Br in its pure form, and as a 30 mass% composite in gypsum. In the latter, we show that after 1000 cycles, which would correspond to about 3 years of use as a solar energy storage material, the temperature of the transition changes by less than 1 K and the enthalpy of transition is reduced by less than 3%. We also report the heat capacity and thermal conductivity of (n-C6H13)2NH2Br in the temperature range below and above the phase transition, and the volume change associated with the transition.
Compounds
# Formula Name
1 C12H28BrN dihexylammonium bromide
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • DSC
  • 1