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Amira Mohd Nasib
Preparation of supported-deep eutectic solvent membranes: Effects of bath medium composition on the structure and performance of supported-deep eutectic solvent membrane for CO2/N2 gas separation
2020-05-01
,
Amira Mohd Nasib
,
Mohd Irfan Hatim Mohamed Dzahir
,
Nora Jullok
,
Mohamad Syahmie Mohamad Rasidi
Polyvinylidene fluoride-co-polytetrafluoroethylene, PVDF-co-PTFE polymer was used as a membrane support. The asymmetric membranes were formed by immersion of casted membrane film into the coagulation bath. This work manipulated the coagulant bath medium by mixing ethanol with distilled water at different weight percentages (0, 25 and 50 wt. % of ethanol). The structures of fabricated membranes were observed to have different morphologies. Higher ethanol content altered the membrane structure from finger-like to sponge-like structure, and hence differed in membrane porosity. Vacuum-based technique was chosen to impregnate the deep eutectic solvent (DES) into the pores of membrane support. DES was prepared by mixing choline chloride (ChCl) and ethylene glycol at a ratio of 1:3. Scanning electron microscopy (SEM) was used to study the membrane morphology changes while in order to determine the immobilization of DES, energy dispersive X-ray (EDX) analysis was used. The porosity of fabricated PVDF-co-PTFE membrane was determined by means of gravimetric method. Lastly, the membrane separation performance using CO2 and N2 gasses were used to determine the capability of the supported-DES-membrane. The results demonstrated the highest immobilization of DES in supported membrane pores was achieved when combination of 25 wt. % of ethanol and 75 wt. % distilled water was used as a coagulant bath medium. The respective membrane has 74.5% porosity with the most excellent performance of CO2 separation at 25.5 x 103 GPU with CO2/N2 selectivity of 2.89.