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Papers by amira nasib
Malaysian Journal of Analytical Science, Apr 21, 2017
Poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-co-PTFE) flat sheet membranes were prepare... more Poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-co-PTFE) flat sheet membranes were prepared via phase inversion process by means of immersion precipitation. The effects on the microstructure of prepared membranes by using different solvents and the effect of polymer solution composition (polymer concentration) on the membrane morphologies and the membrane porosity were studied. Three different solvents were employed, which were, N,N-dimethylacetamide (DMAc), Nmethyl-2-pyrrolidone (NMP) and N,N-dimethylformamide (DMF). Different polymer concentrations were used; 20 wt.%, 25 wt.% and 30 wt.%. Brookfield viscometer was used to measure the viscosity for each polymer solution before the membrane was casting. The morphological study for the cross-sectional area of PVDF-co-PTFE membrane was carried out by using scanning electron microscope (SEM). The membrane porosity was determined by using the weight difference and density resulted from the immersing of dry membrane into octanol for 15 seconds. The results showed that the polymer concentration was a particularly important parameter. At different polymer concentration, the precipitant plays an important role and finally influence the prepared membrane microstructure. At higher concentration of PVDF-co-PTFE polymer, the prepared membrane possessed a sponge-like membrane structures, whereas at lower concentration, a finger-like structure was obtained. It was also found that, the membrane porosity decreases with the increasing of polymer concentration. The effect of different solvent reflected to different morphologies of the prepared flat sheet membranes. Prepared membrane with more sponge-like structure indicated a weak dissolution solvent was used. Hence, a small amount of water needed to induce precipitation and reduced the precipitation rate.
Malaysian Journal of Fundamental and Applied Sciences
Polyvinylidene fluoride-co-polytetrafluoroethylene, PVDF-co-PTFE polymer was used as a membrane s... more 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 fabri...
Malaysian Journal of Analytical Science, Apr 21, 2017
Poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-co-PTFE) flat sheet membranes were prepare... more Poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-co-PTFE) flat sheet membranes were prepared via phase inversion process by means of immersion precipitation. The effects on the microstructure of prepared membranes by using different solvents and the effect of polymer solution composition (polymer concentration) on the membrane morphologies and the membrane porosity were studied. Three different solvents were employed, which were, N,N-dimethylacetamide (DMAc), Nmethyl-2-pyrrolidone (NMP) and N,N-dimethylformamide (DMF). Different polymer concentrations were used; 20 wt.%, 25 wt.% and 30 wt.%. Brookfield viscometer was used to measure the viscosity for each polymer solution before the membrane was casting. The morphological study for the cross-sectional area of PVDF-co-PTFE membrane was carried out by using scanning electron microscope (SEM). The membrane porosity was determined by using the weight difference and density resulted from the immersing of dry membrane into octanol for 15 seconds. The results showed that the polymer concentration was a particularly important parameter. At different polymer concentration, the precipitant plays an important role and finally influence the prepared membrane microstructure. At higher concentration of PVDF-co-PTFE polymer, the prepared membrane possessed a sponge-like membrane structures, whereas at lower concentration, a finger-like structure was obtained. It was also found that, the membrane porosity decreases with the increasing of polymer concentration. The effect of different solvent reflected to different morphologies of the prepared flat sheet membranes. Prepared membrane with more sponge-like structure indicated a weak dissolution solvent was used. Hence, a small amount of water needed to induce precipitation and reduced the precipitation rate.
Malaysian Journal of Fundamental and Applied Sciences
Polyvinylidene fluoride-co-polytetrafluoroethylene, PVDF-co-PTFE polymer was used as a membrane s... more 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 fabri...