Surface chemistry of polymers. The adsorption of carbon dioxide and sulfur dioxide on polyvinylidene chloride

Isotherms for the adsorption of nitrogen (77 K), carbon dioxide (195-247 K) and sulfur dioxide (254-293 K) on polyvinylidene chloride have been measured volumetrically. The <i>B.E.T. </i> cross-sectional areas of 18 Ų (CO₂) and 24 Ų (SO₂) are comparable to liquid density values. The isosteric heat of adsorption of CO₂ is constant for 0.2 <θ < 0.4 and is lower than the latent heat of condensation. For SO₂, the two are practically identical up to the monolayer. Entropy calculations show supermobility in the case of CO₂.