Separation Technology,
M. Zamani; S. R. Taghizadeh; A .R. Zahedipoor; M. Rahbari-sisakht
Abstract
Polysulfone-zinc oxide mixed matrix membrane (MMM) was fabricated. A polyamide layer was formed on the top surface of the membranes using interfacial polymerization process. The properties and structure of the membranes were investigated and the membranes were used for desalination in reverse osmosis ...
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Polysulfone-zinc oxide mixed matrix membrane (MMM) was fabricated. A polyamide layer was formed on the top surface of the membranes using interfacial polymerization process. The properties and structure of the membranes were investigated and the membranes were used for desalination in reverse osmosis process. Cross-sectional images of the membranes substrate showed that the addition of zinc oxide to the polymer matrix resulted in a denser structure and increased the thickness of the sponge-like layer near the lower surface of the membrane. The addition of zinc oxide to the polymer matrix decreased the surface contact angle of the membrane with water, thereby increasing the hydrophilicity of the membrane. The pure water flux of all membranes reduced at the beginning of the process and after 60 min remained almost constant at the values of 19.50 (Lm-2h-1) and 30.20 (Lm-2h-1) for the membrane made with plain polymer and the MMM, respectively. In the reverse osmosis process, the water flux of the membrane fabricated using plain polymer was 9.70 (Lm-2h-1) which increased by 39% and reached to 13.50 (Lm-2h-1) by the addition of zinc oxide nanoparticles. The salt rejection of plain polysulfone membrane was 92.5% which increased to 97.21% with the addition of zinc oxide to the polymer matrix. The addition of zinc oxide nanoparticles to the polymer matrix significantly decreased the water permeability to salt permeability ratio (B/A) from 40.54 to 14.35 (kPa).
Separation Technology,
R. Bakhshi; M. Moraveji; A. Parvareh
Abstract
The polysulfone mixed matrix membranes (MMM) with different concentrations of graphene oxide (0, 0.25, 0.5 wt % of the polymer) are fabricated by a phase separation method. The cross-sectional structures and their upper surface were assessed by the (SEM) surface roughness of the membranes assessed by ...
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The polysulfone mixed matrix membranes (MMM) with different concentrations of graphene oxide (0, 0.25, 0.5 wt % of the polymer) are fabricated by a phase separation method. The cross-sectional structures and their upper surface were assessed by the (SEM) surface roughness of the membranes assessed by (AFM). The mechanical and thermal stability of the fabricated membranes were evaluated as well. The separation of Carbon dioxide, nitrogen and methane from natural gas was considered. Also, by increasing the concentration of graphene oxide in the polymer matrix, the thickness of the spongy structure increases and the holes of the finger-like membranes are also destroyed. From the cross-sectional images of the outer surface of the MMM, it was concluded that an active selector layer was created on the lower surface of the membrane. The membrane tensile strength and the length of the membrane at fracture point increased slightly with an increase in the concentration of graphene oxide. Transition Glass temperature of the membrane increased by the addition of graphene oxide to the structure. From TGA analysis, in the presence of graphene oxide, the thermal stability improved. From the gas permeation test, by the addition of 0.25 % of graphene oxide to the polymer, CO2 permeability was increased from 61.22 GPU to 76.04 GPU, while the addition of 0.5 wt % resulted in a lower permeability (69.55 GPU). The Nitrogen gas permeation flux of membranes decreased from 10.93 GPU to 3.91 GPU by the addition of 0.50 wt % of graphene oxide. The Methane gas permeation flux is reduced from 11.31 GPU to 6.95 GPU and 4.92 GPU by the addition of 0.25 % and 0.50 % of graphene oxide respectively. In conclusion, an increase in the concentration of graphene oxide increased the carbon dioxide selectivity.
Separation Technology,
H. Sanaeepur; A. Ebadi Amooghin; A. Kargari; Mohammadreza Omidkhah; A. Fauzi Ismail; S. Ramakrishna
Volume 16, Issue 2 , June 2019, , Pages 70-94
Abstract
A new method is developed to enhance the gas separation properties of mixed matrix membranes (MMMs) by interior modification of an inorganic nano-porous particle. Ship-in-a-bottle (SIB), as a novel synthesis strategy, is considered to encapsulate a polyaza macrocyclic Ag-ligand complex into the zeolite ...
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A new method is developed to enhance the gas separation properties of mixed matrix membranes (MMMs) by interior modification of an inorganic nano-porous particle. Ship-in-a-bottle (SIB), as a novel synthesis strategy, is considered to encapsulate a polyaza macrocyclic Ag-ligand complex into the zeolite Y, which is resulted in a new host-guest nano-composite. It is consequently incorporated into a glassy polymer matrix to fabricate a novel MMM for CO2 separation. Accordingly, cellulose acetate (CA) with relatively low gas permeability is selected as the membrane polymeric matrix to provide an appropriate opportunity for better tracking the effect of incorporating the new synthesized nano-porous hybrids. The results showed a promising increase in both the CO2 permeability (45.71%) and CO2/N2 selectivity (40.28%) of the prepared MMM over its pristine CA membrane. It can be concluded that the proposed method makes it possible to fabricate novel MMMs with significant intensification in performance of the current MMMs.
Separation Technology,
M. Delavar; Gh. Bakeri; M. Hosseini
Volume 14, Issue 2 , 2017, , Pages 59-73
Abstract
In this study, novel polycarbonate-titanium oxide nanotubes (PC-TNT) ultrafiltration mixed matrix membranes (MMMs) were fabricated for decontamination of Cd2+ and Cu2+ metal ions from aqueous solution. The weight percent of TNTs in the polycarbonate membrane matrix was changed from 0 to 15. The synthesized ...
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In this study, novel polycarbonate-titanium oxide nanotubes (PC-TNT) ultrafiltration mixed matrix membranes (MMMs) were fabricated for decontamination of Cd2+ and Cu2+ metal ions from aqueous solution. The weight percent of TNTs in the polycarbonate membrane matrix was changed from 0 to 15. The synthesized neat PC membrane and PC-TNTs MMMs were characterized with respect to structural morphology and hydrophilicity using scanning electron microscopy (SEM) and water contact angle, respectively. The effects of TNTs loadings on the pure water flux, mean pore size, porosity and water contact angle of fabricated membranes and Cd2+ and Cu2+ heavy metal ion rejection were also studied. By increasing the loading of TNTs nanoparticles in the membrane matrix, the membrane mean pore size tended to increase, while the porosity decreased. Also, the increase in TNTs loading resulted in an increase in membrane water flux which was mainly attributable to the enhancement in mean pore size and partly caused by the decreased contact angle value (more hydrophilic). Of all the membranes studied, it was found by UF experiments that PC-TNT MMM was the most efficient material in heavy metal ions removal due to the superior adsorption capacity of TNTs material. The generic results revealed that TNTs material can be favorite candidates for MMMs preparation in order to be conveniently used in the Cd2+ and Cu2+ heavy metal ions decontamination from polluted water resources.