tailieunhanh - Multi-molecular sorption in yhermodynamic model for heterogeneous mixtures

A thermodynamic model for heterogeneous mixtures involving multi-molecular sorption is proposed. Some complex relationships between sorption potential, diffusion, sorption kinetics polymer network change kinetics, chemical affinity energy of internal changes and physico- chemical properties of polymer network are obtained. This model has interpreted some experimental results of fluid sorption in polymer network. Proposed model may be also used for study of other problems in heterogeneous mixture of fluid and polymers. | Journal of Chemistry Vol. 43 5 P. 647 - 651 2005 MULTI-MOLECULAR SORPTION IN THERMODyNAMIC MODEL FOR HETEROGENEOUS MIXTURES Received 26 October 2004 NGUyEN THE NGHIÊM1 LE ANH TUAN2 QUACH DANG TRIEU2 t institute of Material Technology Vietnam Academy of Science Technology institute of Chemistry Vietnam Academy of Science Technology SUMMARY A thermodynamic model for heterogeneous mixtures involving multi-molecular sorption is proposed. Some complex relationships between sorption potential diffusion sorption kinetics polymer network change kinetics chemical affinity energy of internal changes and physicochemical properties of polymer network are obtained. This model has interpreted some experimental results of fluid sorption in polymer network. Proposed model may be also used for study of other problems in heterogeneous mixture of fluid and polymers. It is well know that sorption isotherm is a related to penetrant pressure and amount of penetrant sorption molecules in polymers at steady state. Sorption steady state is a thermodynamic state at which the sorption kinetics are annulled . kinetics of creation sorption species sorption clusters lk 0 and one can obtain following equation 1 C Ẹ K ln i c p Ì ý k ks J 1 1 Where C is a fluid sorption concentration in polymer Ki is a coefficient inversely proportional to energy creating sorption species E for i-th type i 1 2 etc. 1 _ ki -Ei K RT 2 P is a fluid pressure k s is a sorption kinetics interaction coefficient for i-th sorption type ni is a number of penetrant molecules associated with sorption centers for i-th sorption type. Equation 1 shows that there are three main kinds of sorption parameters that can influence the behaviors of fluid sorption in polymers. Depending on thermodynamic conditions . at temperature higher or lower than glass transition temperature Tg properties and structure of polymer and penetrants are remarkably changed the parameters K and k and ni would have different value and due to the .