alcohols (C 1 -C 7 ), as well as N 2 or other organic molecules, The extent of adsorption of vinyl chloride monomer (VCM) on is employed (2). Then logarithmic plots log N ร
f (log s) polyvinyl chloride (PVC) beads of various size was examined using easily provide the D values. the inverse gas chromatography technique at 288, 295, 303, and Another technique also useful in determining D is to em-313 K. The sizes of the PVC beads were 60-80, 100-120, and ploy particles of adsorbent of varying size (diameter) d, on 150-200 mesh. On them the specific retention volume V g (ml/g) which a single molecule is adsorbed. Then if the number of of the injected gaseous monomer was determined. V g depends on species adsorbed, let us say on unit mass of the particles, the mean particle size dU of PVC beads according to the relationship equals N, the following proportionality holds: log V g ร
(D 0 3)log dU , 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) N ฯฐ d D0 3 .
[2]
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-The results obtained by this method (2) are referred to a dimensional material in relation to VCM adsorption at higher number of solids such as industrial adsorbents (silica, alutemperatures, whereas at lower temperatures it looks more like a mina), natural rocks (quartz, feldspar, kaolinite), and varithree-dimensional Euclidean solid.