Fractal Dimensionality of Vinyl Chloride Monomer Adsorption on Polyvinyl Chloride Particles
The extent of adsorption of vinyl chloride monomer (VCM) on polyvinyl chloride (PVC) beads of various size was examined using the inverse gas chromatography technique at 288, 295, 303, and 313 K. The sizes of the PVC beads were 60-80, 100-120, and 150-200 mesh. On them the specific retention volume Vg (ml/g) of the injected gaseous monomer was determined. Vg depends on the mean particle size &dmacr; of PVC beads according to the relationship log Vg = (D - 3)log &dmacr;, from which the mass fractal D values were determined between 2.95 and 2.63 depending on the temperature and the dilution of monomer. Higher temperatures (313 K) are associated with lower D values (2.63-2.67), whereas lower temperatures (288 K) are associated with higher D values (2.87-2.95). These results suggest that the PVC behaves more as a two-dimensional material in relation to VCM adsorption at higher temperatures, whereas at lower temperatures it looks more like a three-dimensional Euclidean solid.
Demertzis
PG
Department of Chemistry, University of Ioannina, Ioannina, GR-45110, Greece
Pomonis
PJ