ZIF-8/PPO混合基質複合薄膜用於滲透蒸發分離醋酸水溶液之研究

Abstract

In this study, ZIF-8 was added into a hydrophobic polymer, poly(2,6-dimethyl-p-phenylene oxide), and casted on PAN support membranes to form a mixed matrix composite membranes. The MMCMs was applied to separate 90wt% acetic acid aqueous solution. However, the pervaporation performance have limited by coupling effect between acetic acid and water at room temperature. This problem was solved by increasing operation temperature, because the kinetic energy of molecular was increased at high temperature that could decreased the interaction between water and acetic acid. On the other hand, the PPO polymer was a glassy polymer that the polymer chain cannot move easily at high temperature, so the pervaporation performance still good at high temperature. The pervaporation separation performance was studied by changing the amount of ZIF-8 and heat treatment. The dispersion of ZIF-8 in the PPO active layer was evaluated by FESEM and EDX images to characterize the structure and dispersible. The membrane structure was correlated with the pervaporation performance. In other ways, the physicochemical properties of ZIF-8/PPO mixed matrix composite membranes was characterized by FTIR、TGA、DSC、water contact angle. The pervaporation results show the performance is limited by coupling effect. In research, heat-treated ZIF-8/PPO mixed matrix composite membranes could improve the pervaporation performance. The flux is 112g/m2h and the separation factor is 1491 at best condition 100°C and 30minutes. The permeation rate and water concentration in permeat of ZIF-8/PPO mixed matrix composite membranes both increased with operation temperature increasing. It confirmed that coupling effect can be reduce by high temperature operation.