Zur Bestimmung der Grenzflächenspannung Salzhydratschmelze-Halogenkohlenwasserstoff von „Galisol”-Latentwärmespeicher-Stoffkombinationen

The characterization of „Galisol”-heat storage units requires the determination of interfacial tension between the heat storage material (salt hydrate) and the heat transfer liquid (halogened hydrocarbon). Hence, an apparatus was developed to investigate this interfacial tension under „Galisol” -conditions (working temperature, pressure higher than 0, 1 MPa). The apparatus based on the pendant drop method. The interfacial tension in the system Na2SO4-H2O-n-alkylsulphate-C2H5Br was investigated as a function of the concentration of the surfactant and the time to adjust the equilibrium of the surfactant at the interface. The typical behaviour of the interfacial tension as a function of surfactant concentration in the investigated system can be observed. The cmc was found at 0,025% surfactant.