Measurement and Correlation of the Solubility of High Pressure COィイD22ィエD2 containing Supercritical State to Polymers

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The development of techniques for depressing green house effect are global subject for scientists. In these techniques membrance separation of COィイD22ィエD2 from various sources using polymer film will be most hopeful because of a low energy consumption. For the efficient development of polymeric materials for COィイD22ィエD2 separation, solubility and diffusion coefficient of COィイD22ィエD2 are important physical properties as well as that of dynamics. Typical methods for the solubility measurements are pressure decay method, weight change method and method uses chromatography. Though the measurement is possible by all of these three methods, data obtained by them include uncontainty arises from the volume change of polymer by the sorption of gas. To overcome the problem, separate experiments and/or theoretical treatment for volume change correction must be conducted.In this study for the clarification of the sorption behavior (adsorption, dissolution and diffusion) of high-pressure carbon dio … More xide including supercritical state to polymers. High pressure apparatus which measures the solubility by the frequency change of quarts crystal microbalance was constructed. With apparatus, it became possible to measure the solubility with high precision without receiving the effect of buoyancy which becomes an important problem under high-pressure condition. Actually, it was possible to measure the solubility of the carbon dioxide at pressures higher than the conventional apparatus. With using polystyrene, poly (pentafluorostyrene), plasma polymered styrene, and plasma polymerized pentafluorostyrene as a model polymer; it was clarified that the solubility has a linear relationship with the activity of carbon dioxide. At the same time, from a transient behavior of the frequency, a phenomenon which resembles the critical throuwing down or a significant decrease of the diffusion coefficient in the vicinity of the critical point of carbon dioxide, was observed. The diffusion coefficient that calculated from the transient behavior of frequency was two orders smaller than the literature value. It was also showed that the diffusion phenomena of carbon dioxide to polymers would be strongly affected by an adsorption layer on the polymer surface. Less