ABSTRACT

In the present work, phase change material (PCM) nanofluids were developed for heat transfer applications. Three PCMs, stearic acid, myristic acid and paraffin, were dispersed in water using two different emulsification methods; high-energy ultrasound processing and low-energy phase inversion composition (PIC). In ultrasound processing desired amounts of reagents are stirred vigorously in the presence of an optimized surfactant, while in the PIC method, spontaneous curvature of surfactants is tuned in regulation of the geometry at the interface of two immiscible phases by controlling the concentration of reagents. In this study, paraffin nanofluids with an average particle size of 50nm were produced successfully by ultrasound processing. In addition, fatty acid nanofluids were prepared using the PIC procedure, in which slow water addition and partial neutralization of fatty acids were utilized to achieve the phase inversion. Stable stearic acid nanofluids were successfully prepared with optimized surfactant composition, whereas all myristic acid emulsions tested were unstable. For both of the fatty acid nanofluids, combination of ionic and nonionic surfactant resulted in best stability. Thermal and structural properties of the prepared nanofluids were also characterized.

Compounds

#	Formula	Name
1	C18H36O2	octadecanoic acid
2	C14H28O2	tetradecanoic acid
3	C12H25NaO4S	sodium dodecyl sulfate

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	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	1	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal		Crystal	Small sample (50 mg) DSC	1
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Small sample (50 mg) DSC	1
POMD	2	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal		Crystal	Small sample (50 mg) DSC	1
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Small sample (50 mg) DSC	1
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	2

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Preparation of paraffin and fatty acid phase changing nanoemulsions for heat transfer

Puupponen, S.[Salla], Seppala, A.[Ari], Vartia, O.[Olli], Saari, K.[Kari], Ala-Nissila, T.[Tapio]

ABSTRACT