Changes of the surface and interface tension with temperature for washing liquids and alkanes were measured by FACE surface tensiometer. Using the extended Fowkes' equation, the dispersion and polar force components of the surface tension were estimat...
Changes of the surface and interface tension with temperature for washing liquids and alkanes were measured by FACE surface tensiometer. Using the extended Fowkes' equation, the dispersion and polar force components of the surface tension were estimated.
The results were as follows;
1. The surface tensions of washing liquids and alkanes decreased almost linearly with the increase of temperature.
2. The interface tensions of 0.25% DBS/alkane increased slowly with the increase of temperature. In the case of nonionic surfactant solutions, however, the interface tensions with alkanes varied with the number of hydrophilic ethylene oxide(EO) groups.
3. Of the surface tension of water at 20℃, the dispersion force component was 25.3 dyn/cm and the polar force component was 47.8 dyn/cm. As the temperature increased, both the polar and dispersion force components decreased in a similar fashion.
4. The dispersion force component of surface tension of 0.25% DBS solution was 30.0 dyn/cm, and the polar force component was 2.2 dyn/cm at 20℃. The two components decreased with the increase of temperature.
5. As the temperature increased, the dispersion force component of surface tension decreased and the polar force component increased significantly for 0.25% NPPG-7.5E0 solution. In the case of 025% NPPG-10EO, both the dispersion and polar force components decreased slowly, but the polar force component is expected to increase from 60℃. However, the polar force component of surface tension decreased with the increase of temperature for 0.25% NPPG-15EO solution, and at the temperature higher than 60℃ the surface tension is expected to be composed of only dispersion force component.