Thermal stabilities and heat capacities of C4mim[Tf2N] ionic liquids are determined at the temperature range of 298–600 K by differential thermal analysis (DTA) and differential scanning calorimetry (DSC) methods. Heat capacities measured by DTA and DSC methods showed good agreements. Based on the linear equation of heat capacity data, thermodynamic properties such as enthalpy, entropy and Gibbs energy changes are calculated and fitted into regression equations. These property data would be essential for the applications of ionic liquids in heat transfer and thermal energy storage systems.
BlakeD., MoensL., RudnickiD., HaleM., ReddyR. and GlatzmaierG.: ‘Advanced heat transfer and thermal storage fluids’, Proc. 2003 Parabolic Trough Thermal Energy Storage Workshop, Golden, CO, USA, February 2003, NREL. Paper # 4.
2.
ZhangZ. and ReddyR. G.: ‘Fundamentals of advanced materials for energy conversion’, Proc. EPD Cong., (ed.ChandraD. and BautistaR. G.), 33–39, 2002, Warrendale, PA, TMS.
3.
HolbreyJ. D., ReichertW. M., ReddyR. G. and RogersR. D.: ‘Heat capacities of ionic liquids and their applications as thermal fluids’, in ‘Ionic liquids as green solvents: progress and prospects’, (ed.RogersR. D. and SeddonK. R.), ACS Symposium Series 856, 121–133; 2003, New York, ACS.
4.
ZhangM. and ReddyR. G.: ‘Application of C4min[Tf2N] ionic liquid as thermal storage and heat transfer fluids’, ECS Trans., 2007, 2, (28), 27–32.
5.
ZhangM., KamavaramV. and ReddyR. G.: ‘Thermodynamic properties of 1-butyl-3-methylimidazolium (C4mimC1) ionic liquid’, J. Phase Equilib. Diffus., 2005, 26, (2), 124–130.
6.
WassercheidP. and WaltonT.: ‘Ionic liquids in synthesis’, 7-19; 2003, Weinhem, Wiley-VCH Verlag GmbH & Co. KGaA.
7.
ReddyR. G., ZhangZ., ArenasM. F. and BlakeD. M.: ‘Thermal stability and corrosivity of ionic liquids as thermal energy storage media’, High Temp. Mater. Processes, 2003, 22, (2), 87–94.
8.
ZhangM., KamavaramV. and ReddyR. G.: ‘Ionic liquid metallurgy: novel electrolytes for metals extraction and refining technology’, Miner. Metall Process., 2006, 23, (4), 177–186.
9.
YangJ. and RoyC.: ‘Using DTA to quantitatively determine enthalpy change over a wide temperature range by the “mass-difference baseline method'”, Thermochim. Acta, 1999, 333, 131–140.
10.
HatakeyamaT. and LiuZ.: ‘Handbook of thermal analysis’, 424; 1984, New York, John Wiley & Sons.
11.
ZhangM. and ReddyR. G.: ‘Evaluation of ionic liquids as heat transfer materials in thermal storage systems’, in ‘Energy: energy materials’, (ed.DoganF.), 151–160; 2007, Materials Park, OH, ASM International.
12.
ReddyR. G., ZhangZ., ArenasM. F. and BlakeD. M.: ‘Thermal stability and corrosivity of ionic liquids as thermal energy storage media’, High Temp. Mater. Processes, 2003, 22, 87–94.
13.
SmothersW. J. and ChiangY.: ‘Handbook of differential thermal analysis’, 90-98; 1966, New York, Chemical Publishing Company, Inc.
14.
GokcenN. A. and ReddyR. G.: ‘Thermodynamics’, 2nd edn; 1996, New York, Plenum Press.
