scholarly journals Hot-Pressed Wet-Laid Polyethylene Terephthalate Nonwoven as Support for Separation Membranes

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1547 ◽  
Author(s):  
Lei Xia ◽  
Quping Zhang ◽  
Xupin Zhuang ◽  
Shuo Zhang ◽  
Chengpu Duan ◽  
...  
Keyword(s):  
Response Surface ◽  
Polyethylene Terephthalate ◽  
Composite Membrane ◽  
Hot Pressing ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Separation Membranes ◽  
Phase Inversion Technique ◽  
Small Pore

In this work, a polyethylene terephthalate (PET) nonwoven support was prepared by wet-laid and hot-press technology and used as support for separation membranes. The properties of the PET nonwoven support were studied to determine the effect of hot-pressing parameters and PET fiber ratio, and were optimized by response surface methodology. Result showed that the PET nonwoven support with 62% low melting point PET (LPET-180) fibers obtained satisfactory properties and structure after hot pressing at 220 °C under the pressure of 9 MPa for 20 s. The response surface analysis indicated that the temperature and time of hot pressing and the fiber ratio were the most important factors affecting the strength and air permeability of the PET nonwoven support. After hot pressing, the PET nonwoven support exhibited interconnected structure, small pore size, low porosity, and high strength. Then phase inversion technique was applied to prepare a polysulfone (PSF) layer on the PET nonwoven support and an ultra-thin polyamide (PA) active layer was prepared by interfacial polymerization on the PSF layer. The practicality of PET nonwoven support was verified by testing the pure water flux and retention of the PA composite membrane and the structural change of the PA composite membrane before and after use. The results proved the feasibility and remarkable application prospects of hot-pressed wet-laid PET nonwoven support as support for separation membranes.

Composite Membrane with a Calixarene-Containing Polyamide Functional Layer

2018 ◽  
Vol 71 (5) ◽  
pp. 360 ◽  
Author(s):  
Shun Ren ◽  
Dong-Qing Liu ◽  
Rui-Xiang Miao ◽  
Ze-Xian Zhu ◽  
Yu-Feng Zhang
Keyword(s):  
Composite Membrane ◽  
Photoelectron Spectroscopy ◽  
Interfacial Polymerization ◽  
Film Formation ◽  
Pure Water ◽  
Water Flux ◽  
Metal Cations ◽  
Heat Treating ◽  
Skin Layer ◽  
Functional Layer

Monolayer thin films were prepared at the interface of hexane and water to investigate the film formation ability of monomers through interfacial polymerization (IP). A tetra-calix[4]arene chloride derivative (CC) and a diamino-terminated PEG-1000 (DAP) produced a high strength membrane among the tested monomers. IP is consequently proposed to prepare a composite membrane with CC and DAP on a polysulfone (PSF) bulk membrane used for ultrafiltration. The top layer was cross-linked by heat-treating at 60°C for 2 min, with DAP (2 wt.-%) in water and CC (0.05 wt.-%) in hexane. Attenuated total reflectance (ATR)-FTIR and X-ray photoelectron spectroscopy data confirmed that a polyamide was formed on the surface of the PSF substrate. The skin layer was a 3 μm thick smooth thin-film as determined by field emission scanning electron microscopy (FE-SEM), and was also compact without gaps. Pure water flux was ~80.5 L m−2 h−1 under 0.5 MPa. Rejection of MgSO4 was round 22 %, since the calixarene-containing network was a sparse grid, and also had an affinity for metal cations. Although the skin of the composite membrane was compact under SEM, it was easy for metal cations to transfer through. This composite membrane might have good performance in other separation areas as a result of the special structure imparted by using the calixarenes as cross-linking knots.

scholarly journals Antifouling Polyethersulfone-Petrol Soot Nanoparticles Composite Ultrafiltration Membrane for Dye Removal in Wastewater

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 361
Author(s):  
Nkechi P. Nwafor ◽  
Richard M. Moutloali ◽  
Keneiloe Sikhwivhilu ◽  
Oluwole B. Familoni ◽  
Luqman A. Adams
Keyword(s):  
Composite Membrane ◽  
Membrane Filtration ◽  
Dye Removal ◽  
Pure Water ◽  
Water Flux ◽  
Composite Membranes ◽  
Water Remediation ◽  
Blue Dye ◽  
Phase Inversion Technique ◽  
Pure Water Flux

Engineered nanoparticles are known to boost membrane performance in membrane technology. Hitherto, tunable properties that lead to improved hydrophilicity due to increased surface oxygen functionalities upon oxidation of petrol soot have not been fully exploited in membrane filtration technology. Herein, the integration of oxidized petrol soot nanoparticles (PSN) into polyethersulfone ultrafiltration membranes produced via phase inversion technique for dye removal in wastewater is reported. The nanoparticles, as well as the composite membranes, were characterized with diverse physicochemical methods, particularly TEM, SEM, BET, AFM, contact angle, etc. The effect of varying the ratio of PSN (0.05–1.0 wt %) on the properties of the composite membrane was evaluated. The composite membranes displayed increased hydrophilicity, enhanced pure water flux, and antifouling properties relative to the pristine membrane. For example, the obtained pure water flux increased from 130 L·m−2·h−1 for base membrane to 265 L·m−2·h−1 for the best composite membrane (M4). The best flux recovery ratio (FRR) observed for the membranes containing PSN was ca. 80% in contrast to 49% obtained with the pristine membrane indicative of the positive influence of PSN on membrane antifouling behavior. Furthermore, the PSN composite membranes displayed relatively selective anionic dye rejection of ˃95% for Congo red and between 50–71% for methyl orange compared with 42–96% rejection obtained for cationic methylene blue dye with increasing PSN content. The successful fabrication of polyethersulfone–PSN composite membranes by a simple blending process opens a novel route for the preparation of economical, functional, and scalable water purification membranes capable of addressing the complex issue of water remediation of organic azo dyes.

Effects of spinning conditions on structure and properties of aramid-based hollow fiber blend separation membranes

2019 ◽  
pp. 152808371985875 ◽  
Author(s):  
Hongbin Li ◽  
Wenying Shi ◽  
Haixia Zhang ◽  
Xiaohong Qin
Keyword(s):  
Hollow Fiber ◽  
Pure Water ◽  
Water Flux ◽  
Coagulation Bath ◽  
Structure And Properties ◽  
Surface Hydrophilicity ◽  
Separation Membranes ◽  
Small Pore ◽  
Blend Membranes ◽  
Rigid Rod

The rigid-rod-like poly(p-phenylene terephthalamide) (PPTA), as the raw material of aramid 1414, has the characteristics of high modulus and hydrophilicity. The flat sheet poly(vinylidene fluoride) (PVDF)/PPTA blend separation membranes with improved hydrophilicity and enhanced modulus have been successfully prepared using in situ polycondensation method in our previous study. In this study, PPTA/PVDF hollow fiber blend separation membranes with enhanced hydrophilicity and mechanical strength were fabricated through the dry–wet spinning technique. Monomers of PPTA were polymerized in the PVDF solution, and the polymerization system was directly used as the spinning solution to fabricate the hollow fiber blend membrane. The effects of spinning conditions including the air-gap distance; the composition of core fluid; and composition of coagulation bath on the structure and properties including the separation properties, surface hydrophilicity, and mechanical properties of PPTA/PVDF hollow fiber blend membranes were well investigated. Membrane surface and cross-sectional morphologies were observed through scanning electron microscope. The enhancements of these spinning conditions weakened the phase separation process as a result of the formation of a small pore structure. The pore size distribution, water flux, and solute rejection varied accordingly. Different spinning conditions have different effects on the mechanical and hydrophilic properties of the hollow fiber blend membranes. Compared with pure PVDF hollow fiber membrane, blend membranes fabricated under different spinning conditions exhibited enhanced surface hydrophilicity and tensile properties. Finally, the change rates of the pure water flux and the solute rejection with different spinning conditions were calculated to further analyze and compare the statistically significant effects.

Fabrication and Properties of Poly(Ether Imide)/Poly(Vinyl Alcohol) Composite Ultrafiltration Membrane

2012 ◽  
Vol 531-532 ◽  
pp. 18-21 ◽  
Author(s):  
Watchanida Chinpa
Keyword(s):  
Composite Membrane ◽  
Membrane Fouling ◽  
Vinyl Alcohol ◽  
Pure Water ◽  
Water Flux ◽  
Composite Membranes ◽  
Dip Coating ◽  
Poly Vinyl Alcohol ◽  
Phase Inversion Technique ◽  
Pure Water Flux

A poly(ether imide) (PEI) composite membrane was prepared by dip coating a PEI membrane pretreated with 2-aminoethanole (AEOH) into an aqueous solution of poly(vinyl alcohol) PVA and glutaraldehyde (GA). PEI membrane support was firstly prepared via phase inversion technique by casting a solution of PEI in N-methylpyrrolidone (NMP), using water as non-solvent. The hydrophilicity, permeability, anti-fouling and mechanical properties of unmodified PEI and PEI/PVA composite membranes were investigated. By comparison with the unmodified PEI membrane, the PEI/PVA composite membrane exhibited a higher pure water flux and an increase in its hydrophilicity. In addition, the flux recovery of the pure water flux of the composite PEI membrane was higher than that of the unmodified PEI membrane. This indicated that the obtained composite membrane could reduce the membrane fouling and improve its use for ultrafiltration.

scholarly journals Preparation of defect free TFC FO membranes using robust and highly porous ceramic substrate

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Jincai Su ◽  
Yanyan Wei ◽  
Hui Li
Keyword(s):  
Osmotic Pressure ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Porous Ceramic ◽  
Water Flux ◽  
Solute Flux ◽  
Structural Parameter ◽  
Solute Permeability ◽  
Draw Solution ◽  
Surface Pores

In this study, robust and defect-free thin film composite (TFC) forward osmosis (FO) membranes have been successfully fabricated using ceramic hollow fibers as the substrate. Polydopamine (PDA) coating under controlled conditions is effective to reduce the surface pores of the substrate and make the substrate smooth enough for the interfacial polymerization. The pure water permeability (A), solute permeability (B) and structural parameter (S) of the resultant FO membrane are 0.854 L·m-2h-1bar-1 (LMH/Bar) 0.186 L·m-2h-1 (LMH) and 1720 µm, respectively. The water flux and reverse draw solute flux are measured using NaCl and proprietary ferric sodium citrate (FeNaCA) draw solutions at low and high osmotic pressure ranges. With increasing the osmotic pressure, higher water flux is obtained but its increase is not directly proportional to the increase in the osmotic pressure. At the membrane surface, the effect of dilutive concentration polarization is much less serious for FeNaCA draw solutions. At an osmotic pressure of 89.6 bar, the developed TFC membrane generates water fluxes of 11.5 and 30.0 LMH using NaCl and synthesized FeNaCA draw solutions. The corresponding reverse draw solute flux is 7.0 g·m-2h-1 (gMH) for NaCl draw solution but it is not detectable for FeNaCA draw solution. This means that the developed TFC FO membranes are defect free and their surface pores are at molecular level. The performance of the developed TFC FO membranes are also demonstrated for the enrichment of BSA protein.

scholarly journals Effect of Kenaf MCC composition on Thin Film Composite membrane for NaCI Rejection

2019 ◽  
Vol 258 ◽  
pp. 04003
Author(s):  
Azman Ismail ◽  
Ramlah Mohd Tajuddin ◽  
Hamizah Mohktar ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Thin Film ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Sem Images ◽  
Water Contact ◽  
Membrane Performance ◽  
Pure Water Flux

A modified thin film PSf-MCC reverse osmosis membrane was prepared by interfacial polymerization between aqueous MPD and TMC as the organic monomer. Aim of this study is to determine the effect of MCC in membrane formulation and fabrication. The surface and cross section morphology of TFC PSF/MCC membrane shows MCC particle which able to improve hydrophilicity of the membrane. The SEM images showed dense and porous structure of the MCC incorporated membranes. In addition, the water contact angle measurement also confirmed the increased hydrophilicity of the modified membranes. The effect of MCC on membrane matric influence the membrane performance in terms of NaCl rejection and pure water flux. Results showed that TFC PSf/MCC membrane shows NaCl rejection up to 98.9% compared with TFC PSf membrane. TFC PSf/MCC membrane also showed the highest pure water flux which is 3.712 Lm2/hr compare with TFC PSF membrane which is 3.606 Lm2/hr. The overall result proved that MCC particle could improve membrane hydrophilicity hence, increased pure water flux and salt rejection.

scholarly journals Development of permeability properties of polyamide thin film composite nanofiltration membrane by using the dimethyl sulfoxide additive

2014 ◽  
Vol 4 (3) ◽  
pp. 174-181 ◽  
Author(s):  
Ahmad Akbari ◽  
Sayed Majid Mojallali Rostami
Keyword(s):  
Thin Film ◽  
Dimethyl Sulfoxide ◽  
Aqueous Phase ◽  
High Performance ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Film Composite ◽  
Chemical Structures ◽  
Thin Film Composite

A novel polyamide thin film composite (PATFC) as a nanofiltration (NF) membrane was prepared by a modified interfacial polymerization (IP) reaction. Herein trimesoyl chloride and piperazine as the reagents, dimethyl sulfoxide (DMSO) as additive and polysulfone (PSF) ultrafiltration membrane as support were used respectively. The main goal of the present study is to improve TFC membrane water flux by addition of DMSO into the aqueous phase of IP reaction, without considerable rejection loss. Morphological, roughness, and chemical structures of the PATFC membrane were analyzed by scanning electron microscopy, atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FT-IR), respectively. The AFM analysis demonstrated that as DMSO was added to the aqueous phase, the surface roughness of PATFC membrane increased. Results showed that the pure water flux of modified-PATFC membranes increased up to 46%, compared to nonmodified-PATFC membrane, while salt rejection was not sacrificed considerably. The results elucidated that the addition of DMSO leads to an increase in the number of cross-linking bonds between monomers and pore diameter, which results in enhancement of the membrane flux. Finally, the results showed that the newly developed PATFC membrane is a high-performance NF membrane which augments the efficiency of conventional PATFC membrane.

IMPACTS OF HYDROPHILIC NANOFILLERS ON SEPARATION PERFORMANCE OF THIN FILM NANOCOMPOSITE REVERSE OSMOSIS MEMBRANE

2016 ◽  
Vol 78 (12) ◽  
Author(s):  
C. Y. Chong ◽  
G. S. Lai ◽  
W. J. Lau ◽  
N. Yusof ◽  
P. S. Goh ◽  
...  
Keyword(s):  
Thin Film ◽  
Water Permeability ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Water Desalination ◽  
Separation Performance ◽  
Salt Rejection ◽  
Tfc Membrane ◽  
Thin Film Nanocomposite

The membrane technology is still considered a costly method to produce potable water. In view of this, RO membrane with enhanced water permeability without trade-off in salt rejection is desirable as it could further reduce the cost for water desalination. In this study, thin film nanocomposite (TFN) membranes containing 0.05 or 0.10 w/v% hydrophilic nanofillers in polyamide layer were synthesized via interfacial polymerization of piperazine and trimesoyl chloride monomers. The resultant TFN membranes were characterized and compared with a control thin film composite (TFC) membrane. Results from the filtration experiments showed that TFN membranes exhibited higher water permeability, salt rejection and fouling resistance compared to that of the TFC membrane. Excessive amount of nanofillers incorporated in the membrane PA layer however negatively affected the cross-linking in the polymer matrix, thus deteriorating the membrane salt rejection. TFN membrane containing 0.05 w/v% of nanofillers showed better performances than the TFC membrane, recording a pure water flux of 11.2 L/m2∙h, and salt rejection of 95.4%, 97.3% and 97.5% against NaCl, Na2SO4 and MgSO4, respectively. 

Membrane Performance: TiO2 Nanoparticles Coated on Polysulfone (PSf) Ultrafiltration Membrane Surfaces

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Siti Hawa Mohamad ◽  
Hasan Zuhudi Abdullah ◽  
Maizlinda Izwana Idris ◽  
Zawati Harun
Keyword(s):  
Tio2 Nanoparticles ◽  
Uv Light ◽  
Pure Water ◽  
Water Flux ◽  
Sem Analysis ◽  
Ultrafiltration Membrane ◽  
Membrane Surfaces ◽  
Phase Inversion Technique ◽  
Coated Membranes ◽  
Uv Lamp

This study focuses on the modification polysulfone (PSf) ultrafiltration membrane surfaces via coated and irradiated with titanium dioxide (TiO2) nanoparticles with UV lights respectively. Basically, the flat sheet membrane was prepared using phase inversion technique with three conditions: (i) uncoated PSf membrane, (ii) coated PSf membrane with TiO2 and (iii) PSf membrane coated with TiO2 irradiated to UV. The coating process was carried out using dipping method into TiO2 nanoparticles suspension at different concentrations (0.01, 0.03 and 0.05 wt.%). Membrane was immersed in all suspension for 15 and 30 minutes. Then, coated membranes were exposured under 184 Watts UV lamp at two different durations, 15 and 30 minutes. The performance of membranes was evaluated in terms of pure water flux (PWF) and humic acid (HA) rejection. The morphology of membranes was characterized using scanning electron microscopy (SEM). Analysis of the result revealed that 15 minutes immersion of membrane in TiO2 suspension showed a better performance in term permeation and rejection of compared to 30 min immersion. This is due to the pore plugging as time of immersion increased. Therefore, the coated membranes with 0.03 wt.% of TiO2 nanoparticles at 15 minutes immersion and 15 minutes exposure of UV light irradiation were determined as an ideal performance of rejection and permeation compared to the other.

scholarly journals Improving the Structural Parameter of the Membrane Sublayer for Enhanced Forward Osmosis

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 448
Author(s):  
Jin Fei Sark ◽  
Nora Jullok ◽  
Woei Jye Lau
Keyword(s):  
Water Permeability ◽  
Elevated Temperatures ◽  
Interfacial Polymerization ◽  
Water Flux ◽  
Forward Osmosis ◽  
Salt Flux ◽  
Structural Parameter ◽  
Asymmetric Membrane ◽  
S Parameter ◽  
Phase Inversion Technique

The structural (S) parameter of a medium is used to represent the mass transport resistance of an asymmetric membrane. In this study, we aimed to fabricate a membrane sublayer using a novel composition to improve the S parameter for enhanced forward osmosis (FO). Thin film composite (TFC) membranes using polyamide (PA) as an active layer and different polysulfone:polyethersulfone (PSf:PES) supports as sublayers were prepared via the phase inversion technique, followed by interfacial polymerization. The membrane made with a PSf:PES ratio of 2:3 was observed to have the lowest contact angle (CA) with the highest overall porosity. It also had the highest water permeability (A; 3.79 ± 1.06 L m−2 h−1 bar−1) and salt permeability (B; 8.42 ± 2.34 g m−2 h−1), as well as a good NaCl rejection rate of 74%. An increase in porosity at elevated temperatures from 30 to 40 °C decreased Sint from 184 ± 4 to 159 ± 2 μm. At elevated temperatures, significant increases in the water flux from 13.81 to 42.86 L m−2 h−1 and reverse salt flux (RSF) from 12.74 to 460 g m−2 h−1 occur, reducing Seff from 152 ± 26 to 120 ± 14 μm. Sint is a temperature-dependent parameter, whereas Seff can only be reduced in a high-water- permeability membrane at elevated temperatures.

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