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Membrane Water Treatment Volume 7, Number 5, September 2016 , pages 377-401 DOI: https://doi.org/10.12989/mwt.2016.7.5.377 |
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Preparation and characterization of PVDF/TiO2 composite ultrafiltration membranes using mixed solvents |
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Maryam Tavakolmoghadam, Toraj Mohammadi and Mahmood Hemmati
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| Abstract | ||
| To study the effect of titanium dioxide (TiO2) nanoparticles on membrane performance and structure and to explore possible improvement of using mixed solvents in the casting solution, composite polyvinylidene fluoride (PVDF) ultrafiltration membranes were prepared via immersion precipitation method using a mixture of two solvents triethyl phosphate (TEP) and dimethylacetamide (DMAc) and addition of TiO2 nanoparticles. Properties of the neat and composite membranes were characterized using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), Atomic force microscopy (AFM) and contact angle and membrane porosity measurements. The neat and composite membranes were further investigated in terms of BSA rejection and flux decline in cross flow filtration experiments. Following hydrophilicity improvement of the PVDF membrane by addition of 0.25 wt.% TiO2, (from 70.53° to 60.5°) degree of flux decline due to irreversible fouling resistance of the composite membrane reduced significantly and the flux recovery ratio (FRR) of 96.85% was obtained. The results showed that using mixed solvents (DMAc/TEP) with lower content of TiO2 nanoparticles (0.25 wt.%) affected the sedimentation rate of nanoparticles and consequently the distribution of nanoparticles in the casting solution and membrane formation which influenced the properties of the ultimate composite membranes. | ||
| Key Words | ||
| polyvinylidene fluoride; mixed solvents; immersion precipitation; titanium dioxide; ultrafiltration membraneess | ||
| Address | ||
| (1) Maryam Tavakolmoghadam, Toraj Mohammadi: Research and Technology Centre for Membrane Processes, Faculty of Chemical Engineering, Iran University of Science and Technology, Narmak, 16846, Tehran, Iran; (2) Maryam Tavakolmoghadam, Mahmood Hemmati: Research Institute of Petroleum Industry, Tehran, Iran. | ||
