T. Hamieh et al., CROSS-SECTIONAL AREAS OF POLAR-MOLECULES ADSORBED ON A MODEL SOLID-SURFACE BY INVERSE GAS-CHROMATOGRAPHY, Le Vide, les couches minces, (272), 1994, pp. 365-368
Citations number
14
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
Inverse gas chromatography (IGC) at infinite dilution was used to eval
uate the surface areas of adsorbed molecules on polytetrafluoroethylen
e (PTFE) fibres (non-polar solid surface). This will allow us to deter
mine the surface area a of the adsorbed molecule of the polar probe if
the dispersive surface energy components gamma(l)(d) of the the probe
and gamma(s)(d) of the solid are known.Polytetrafluoroethylene (PTFE)
in the form of fibres was used as the non-polar solid surface. The su
rface energy gamma(s) of this solid (equal to its dispersive component
gamma(s)) was determined as a function of temperature, through wettin
g measurements using the dynamic contact angle technique. Various mode
ls giving the molecular areas of n-alkanes were used and rested at 50
and 80 degrees C cylindrical molecular model, liquid density model, BE
T method, Kiselev results and the model using the two-dimensional Van
der Waals' constant b that depends on the critical temperature an pres
sure of the liquid. Molecular areas of polar molecules adsorbed on PTF
E were determined by using these various models. Results obtained from
the cylindrical model and Kiselev model showed that these two models
gave the best results at 50 degrees C is comparison with those determi
ned by the other models, whereas, the Van der Waals model allowed us t
o obtain more precise results at higher temperature.