Thermodynamic Investigation of thin n-Heptane films adsorbed on Magnesium Oxide (100) surfaces
Abstract
The thermodynamic properties of thin films of n-Heptane on MgO (100) were measured using high resolution adsorption isotherms between 205 K and 275 K. Heats of adsorption were derived for first and second layer adsorbed on substrate and yield 42.38 ± 0.98 kJ/mol and 40.58 ± 0.46 kJ/mol, respectively. The isothermal compressibility was determined as a function of temperature and used to identify two possible phase transitions at 246.2 ± 1.5 K for the first and at 250.7 ± 0.8 K for the second layer respectively. These results will be compared to previous thermodynamic and neutron diffraction measurements of other shorter chained alkanes.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2007
- Bibcode:
- 2007APS..MARN18002F