Developing thin‐film‐composite forward osmosis membranes on the PES/SPSf substrate through interfacial polymerization

A new scheme has been developed to fabricate high‐performance forward osmosis (FO) membranes through the interfacial polymerization reaction on porous polymeric supports. p‐Phenylenediamine and 1,3,5‐trimesoylchloride were adopted as the monomers for the in‐situ polycondensation reaction to form a thin aromatic polyamide selective layer of 150 nm in thickness on the substrate surface, a lab‐made polyethersulfone (PES)/sulfonated polysulfone (SPSf)‐alloyed porous membrane with enhanced hydrophilicity. Under FO tests, the FO membrane achieved a higher water flux of 69.8 LMH when against deionized water and 25.2 LMH when against a model 3.5 wt % NaCl solution under 5.0 M NaCl as the draw solution in the pressure‐retarded osmosis mode. The PES/SPSf thin‐film‐composite (TFC)‐FO membrane has a smaller structural parameter S of 238 μm than those reported data. The morphology and topology of substrates and TFC‐FO membranes have been studied by means of atomic force microscopy and scanning electronic microscopy. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Thin film composite forward osmosis membranes with poly(2‐hydroxyethyl methacrylate) grafted nano‐TiO2 as additive in substrate

The poly(2‐hydroxyethyl methacrylate) grafted titanium dioxide nanoparticles were synthesized and added to the substrate of flat‐sheet thin film composite forward osmosis (TFC‐FO) membranes. The hydrophilicity of substrate was improved, which was advantageous to enhance the water flux of TFC‐FO membranes. The membranes containing a 3 wt % TiO₂‐PHEMA in the substrate exhibited a finger‐like structure combined with sponge‐like structure, while those with lower or without TiO₂‐PHEMA content showed fully finger‐like structures. As for FO performance, the TFC‐FO membranes with 3 wt % TiO₂‐PHEMA content achieved the highest water flux of 42.8 LMH and 24.2 LMH against the DI water using 2M NaCl as the draw solution tested under the active layer against draw solution (AL‐DS) mode and active layer against feed solution (AL‐FS) mode, respectively. It was proven that the hydrophilic property of membrane substrates was a strong factor influencing the water flux in FO tests. Furthermore, the structural parameter was remarkably decreased with an increase of TiO₂‐PHEMA content in membrane substrate, indicating the reducing of internal concentration polarization. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43719.     

Characteristics and potential applications of a novel forward osmosis hollow fiber membrane

There has been a resurgence of interest in forward osmosis (FO) as a potential means of desalination, dewatering and in pressure retarded osmosis, which Sidney Loeb was advocating over 3 decades ago. This paper describes the characteristics and potential applications of a newly developed FO hollow fiber membrane, which was fabricated by interfacial polymerization on the inner surface of a polyethersulfone (PES) hollow fiber. This FO membrane presents excellent intrinsic separation properties, with a water flux of 42.6 L/m² h using 0.5 M NaCl as the draw solution and DI water as the feed with the active layer facing the draw solution orientation at 23 °C. The corresponding ratio of salt flux to water flux was only 0.094 g/L, which is superior to all other FO membranes reported in the open literature. To evaluate different application scenarios, various NaCl solutions (500 ppm (8.6 mM), 1 wt.% (0.17 M) and 3.5 wt.% (0.59 M)) were used as the feed water to test the performance of the FO membrane. The membrane can achieve a water flux of 12.4 L/m² h with 3.5 wt.% NaCl solution as the feed and 2 M NaCl as the draw solution, suggesting it has good potential for seawater desalination.     

Effect of cellulose triacetate membrane thickness on forward‐osmosis performance and application for spent electroless nickel plating baths

Cellulose triacetate (CTA) forward‐osmosis (FO) membranes were prepared via the phase inversion method. The influence of thickness on the performance and morphology of CTA FO membranes was discussed in detail. When the thickness of the membrane was 50.0 ± 0.5 μm (CTA4), the prototype CTA membranes displayed a water flux of 20.2 L m^?2 h^?1 and a reverse salt transport of 14.6 g m^?2 h^?1 using 1 mol/L NaCl as the draw solution and deionized water as the feed solution during the FO process at 25 °C. In addition, the high‐performance CTA4 FO membranes have been used to process spent electroless nickel plating baths where the water flux could reach 13 L m^?2 h^?1 and NiSO₄·6H₂O crystals occurred in the feed solution of the spent electroless nickel plating baths. The recovery rates of NiSO₄·6H₂O and water from the spent electroless nickel plating baths were 44.54% and 53.53%, respectively. This study focused on improving membrane design for the FO process and finding a new method of waste liquor or wastewater treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45049.     

Synthesis and characterization of PES/PSF/PEG by immersion precipitation for Mediterranean seawater desalination by FO membrane

In the present study, a simple, inexpensive, nontoxic, and environmentally friendly polyethylene glycol (PEG) polymer was used to enhance the hydrophilicity of the forward osmosis (FO) membrane using various PEG concentrations as a pore forming agent in the casting solution of polyethersulfone/polysulfone (PES/PSF) blend membranes. A nonwoven PES/PSF FO blend membrane was fabricated via the immersion precipitation phase inversion technique. The membrane dope solution was cast on polyethylene terephthalate (PET) nonwoven fabric. The results revealed that PEG is a pore forming agent and that adding PEG promotes membrane hydrophilicity. The membrane with 1 wt% PEG (PEG1) had about 27% lower contact angle than the pristine blend membrane. The PEG1 membrane has less tortuosity (which reduces from 3.4–2.73), resulting in a smaller structure parameter (S value) of 277 μm, due to the presence of open pores on the bottom surface structure, which results in diminished ICP. Using 1 M NaCl as the draw solution and distilled water as the feed solution, the PEG1 membrane exhibited higher water flux (136 L m⁻² h⁻¹) and lower reverse salt flux (1.94 g m⁻² h⁻¹). Also, the selectivity of the membrane, specific reverse salt flux, (J_s/J_w) showed lower values (0.014 g/L). Actually, the PEG1 membrane has a 34.6% higher water flux than the commercial nonwoven-cellulose triacetate (NW-CTA) membrane. By means of varied concentrations of NaCl salt solution (0.6, 1, 1.5, and 2 M), the membrane with 1 wt% PEG showed improved FO separation performance with permeate water fluxes of 108, 136, 142, and 163 L m⁻² h⁻¹. In this work, we extend a promising gate for designing fast water flux PES/PSF/PEG FO blend membranes for water desalination.     

Thin-film composite forward osmosis membrane prepared from polyvinyl chloride/cellulose carbamate substrate and its potential application in brackish water desalination

Synthesized by the reaction between α-cellulose and m-tolyl isocyanate (MTI), cellulose carbamate (CC) was blended with polyvinyl chloride (PVC) to fabricate substrates for thin-film composite (TFC) forward osmosis (FO) membranes. The introduction of CC into substrates improved both membrane structure and performance. The substrates exhibited higher porosity and hydrophilicity, and better connective pore structure; while rejection layer exhibited better morphology but limited cross-linked degree decrease after the introduction of CC. According to the results, the CC blend ratio of 10% was the optimal ratio. With this blend ratio, the TFC-10 membrane presented favorable water permeability (1.86 LMH/bar) and structure parameter (337 μm), which resulted in excellent FO performance (water flux with a value of 40.40 LMH and specific salt flux with a value of 0.099 g/L under rejection layer faces draw solution [DS] mode when 1 M NaCl and deionized water were utilized as DS and feed solution). In addition, the TFC-10 membrane showed good water flux and low-sulfate ion leakage in the potential application of brackish water desalination.     

Advanced FO membranes from newly synthesized CAP polymer for wastewater reclamation through an integrated FO‐MD hybrid system

A new cellulose acetate propionate (CAP) polymer has been synthesized and used to prepare high‐performance forward osmosis (FO) membranes. With an almost equal degree of substitution of acetyl and propionyl groups, the CAP‐based dense membranes show more balanced physicochemical properties than conventional cellulose acetate (CA)‐based membranes for FO applications. The former have a lower equilibrium water content (6.6 wt. %), a lower salt diffusivity (1.6×10¹⁴ m² s^?1) and a much lower salt partition coefficient (0.013) compared with the latter. The as‐prepared and annealed CAP‐based hollow fibers have a rough surface with an average pore radius of 0.31 nm and a molecular weight cut off of 226 Da. At a transmembrane pressure of 1 bar, the dual‐layer CAP‐CA hollow fibers show a pure water permeability of 0.80 L m^?2 h^?1 bar^?1 (LMH/bar) and a rejection of 75.5% to NaCl. The CAP‐CA hollow fibers were first tested for their FO performance using 2.0 M NaCl draw solution and deionized water feed. An impressive water flux of 17.5 L m^?2 h^?1 (LMH) and a reverse salt flux of 2.5 g m^?2 h^?1 (gMH) were achieved with the draw solution running against the active CAP layer in the FO tests. The very low reverse salt flux is mainly resulting from the low salt diffusivity and salt partition coefficient of the CAP material. In a hybrid system combining FO and membrane distillation for wastewater reclamation, the newly developed hollow fibers show very encouraging results, that is, water production rate being 13–13.7 LMH, with a MgCl₂ draw solution of only 0.5 M and an operating temperature of 343 K due to the incorporation of bulky propionyl groups with balanced physiochemical properties. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1245–1254, 2013     

Preparation of sulfonated polysulfone/polysulfone and aminated polysulfone/polysulfone blend membranes

Sulfonation and amination of polysulfone (PSf) were performed in this study to improve the hydrophilicity of PSf membranes. The sulfonated polysulfone (SPSf) and aminated polysulfone (APSf) membranes with a higher degree of reaction exhibited a higher water flux and worse mechanical strength than that of the original PSf membranes. Therefore, SPSf/PSf and APSf/PSf blended membranes were prepared in this study to improve their individual properties. By altering the formulations of casting solutions and forming conditions of the membranes (e.g., blending ratios of both polymers, additives, evaporation time, and gelation temperature), different SPSf/PSf and APSf/PSf blending membranes were prepared; and their performance in water flux and salt rejection were measured and are discussed. A difference in salt rejection was also observed between both SPSf/PSf and APSf/PSf blending membranes that rejected the various salts. Experimental results indicated that water flux increased and salt rejection decreased with an increase of the SPSf/PSf blending ratio from 1: 9 to 2: 1. The order of salt rejection, in which the SPSf/PSf blended membranes rejected four varieties of salts, was Na₂SO₄ > MgSO₄ > NaCl > MgCl₂. Furthermore, the opposite order was obtained by the APSf/PSf blended membranes. © 1996 John Wiley & Sons, Inc.     

Cellulose triacetate/LUDOX-SiO2 nanocomposite for synthesis of pervaporation desalination membranes

A series of cellulose triacetate/Ludox-silica nancomposite pervaporation membranes was successfully prepared via solution casting, aiming to improve the performance of cellulose triacetate membranes for desalination. The fabricated nanocomposite membranes were characterized to study the membrane morphology, chemical composition, mechanical properties, and surface hydrophilicity. Furthermore, the desalination performance was investigated as a function of silica (SiO₂) loading (ranging from 1 to 4 wt%) and feed concentration at 30 and 60 g/L of sodium chloride (NaCl). Pervaporation experiments showed that incorporating 4 wt% SiO₂ into a cellulose triacetate (CTA) membrane increased the water flux by a factor 2.5 compared with pristine CTA (from 2.2 to 6.1 kg m⁻² h⁻¹) for a 30 g/L NaCl feed solution at 70°C, while the salt rejection remained above 99%. The CTA/4 wt% SiO₂ membrane was found to have only 21% flux reduction when tested with a 60 g/L NaCl feed solution, without changes in membrane selectivity. This suggests that the developed CTA/Ludox-SiO₂ nanocomposite pervaporation membrane is suitable for desalination.     

Thin-film composite forward osmosis membranes with substrate layer composed of polysulfone blended with PEG or polysulfone grafted PEG methyl ether methacrylate

To advance commercial application of forward osmosis (FO), we investigated the effects of two additives on the performance of polysulfone (PSf) based FO membranes: one is poly(ethylene glycol) (PEG), and another is PSf grafted with PEG methyl ether methacrylate (PSf-g-PEGMA). PSf blended with PEG or PSf-g-PEGMA was used to form a substrate layer, and then polyamide was formed on a support layer by interfacial polymerization. In this study, NaCl (1 mol?L⁻¹) and deionized water were used as the draw solution and the feed solution, respectively. With the increase of PEG content from 0 to 15 wt-%, FO water flux declined by 23.4% to 59.3% compared to a PSf TFC FO membrane. With the increase of PSf-g-PEGMA from 0 to 15 wt-%, the membrane flux showed almost no change at first and then declined by about 52.0% and 50.4%. The PSf with 5 wt-% PSf-g-PEGMA FO membrane showed a higher pure water flux of 8.74 L?m⁻²?h⁻¹ than the commercial HTI membranes (6–8 L?m⁻²?h⁻¹) under the FO mode. Our study suggests that hydrophobic interface is very important for the formation of polyamide, and a small amount of PSf-g-PEGMA can maintain a good condition for the formation of polyamide and reduce internal concentration polarization.     

三乙酸纤维素正渗透膜的制备与性能

以三乙酸纤维素（CTA）为膜材料,1,4-二氧六环、丙酮为溶剂,甲醇、乳酸为添加剂,采用相转换法制备了三乙酸纤维素正渗透膜。研究了不同1,4-二氧六环/丙酮配比、添加剂乳酸含量、挥发时间、膜厚度、热处理温度条件下正渗透膜性能的变化规律。研究表明,当采用纯水为原料液,0.56mol/L CaCl2为汲取液时,优化制备的CTA正渗透膜的水通量达到14.10L/(m2?h),溶质反扩散量为0.031mol/(m2?h);采用0.1mol/L NaCl为原料液,4mol/L葡萄糖为汲取液时,优化制备的CTA正渗透膜的水通量保持在5L/(m2?h)以上,对NaCl的截留率大于99%。CTA正渗透膜相比于HTI膜,具有较高的亲水性、水通量、截留率,稳定性更好。     

High performance forward osmosis cellulose acetate (CA) membrane modified by polyvinyl alcohol and polydopamine

Cellulose acetate (CA) is a low cost and readily available material widely used in forward osmosis (FO) membranes. However, the performance of pure CA membranes is not good enough in salt separation and the traditional modification methods are generally multistep and difficult to control. In this paper, we reported high performance cellulose acetate (CA) composite forward osmosis (FO) membranes modified with polyvinyl alcohol (PVA) and polydopamine (PDA). PVA was first cross-linked onto the surface of CA membranes, and then PDA was coated with a rapid deposition method. The membranes were characterized with respect to membrane chemistry (FTIR and XPS), surface properties comprising wettability (by water contact angle), and osmosis performance. The modified membrane coated by PVA and PDA shown better hydrophilicity and exhibited 16.72 LMH osmotic water flux and 0.14 mMH reverse solute flux with DI water as feed solution and 2.0 M NaCl as draw solution and active layer facing the feed solution. This simple and highly effective modification method makes it as an excellent candidate for further exploration for FO.     

Nanofiltration membranes based on poly(vinyl alcohol) and ionic polymers

Nanofiltration membranes based on poly(vinyl alcohol) (PVA) and ionic polymers, such as sodium alginate (SA) and chitosan, were prepared by casting the respective polymer solutions. The membranes prepared from PVA or PVA–ionic polymer blend were crosslinked in a isopropanol solution using glutaraldehyde as a crosslinking agent. The membranes were characterized with Fourier transform infrared spectroscopy and X‐ray diffractometry and swelling test. The membranes crosslinked through the acetal linkage formation between the  OH groups of PVA and the ionomer and glutaraldehyde appeared to be semicrystalline. To study the permeation properties, the membranes were tested with various feed solutions [sodium sulfate, sodium chloride, poly(ethylene glycol) with 600 g/mol of molecular weight (PEG 600), and isopropyl alcohol]. For example, the permeance and the solute rejection of the 1000 ppm sodium sulfate at 600 psi of upstream pressure through the PVA membrane were 0.55 m³/m² day and over 99%, respectively. The effects of the ionomers on the permeation properties of the PVA membranes were studied using the PVA–SA and PVA–chitosan blend membranes. The addition of small amount of ionic polymers (5 wt %) made the PVA membranes more effective for the organic solute rejection without decrease in their fluxes. The rejection ratios of the PEG 600 and isopropanol were increased substantially. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1755–1762, 1999     

Enhanced hollow fiber membrane performance via semi-dynamic layer-by-layer polyelectrolyte inner surface deposition for nanofiltration and forward osmosis applications

The layer-by-layer (LBL) polyelectrolyte deposited membranes have drawn increasing attention in various applications due to the ease of selective layer formation and their stability and versatility. In this study, the LBL deposition was performed at the inner surface of the polyethersulfone (PES) hollow fiber substrate to form composite nanofiltration (NF) membrane. The semi-dynamic deposition procedure was adopted with the aid of syringes. The newly developed inner deposited (id-LBL) membranes were then tested in NF and forward osmosis (FO) applications and the performance were compared with outer surface deposition as well as some literature data. The id-LBL membranes could not only withstand higher operating pressure but also possess superior hardness rejection especially in high concentration mixed salt solutions (more than 95% rejection to Mg²⁺ and Ca²⁺ in a 5000 ppm total dissolved salt (TDS) mixture under 4.8 bar). As for the FO process, with only two layer deposition, the id-LBL membranes also demonstrated significant performance improvement with increased water flux (up to 70 L/m² h using 0.5 M MgCl₂ as draw solution in active layer facing draw solution configuration) and reduced salt leakage (around 0.5 g/m² h using 1 M MgCl₂ draw solution in active layer facing feed water configuration). This study suggests that for hollow fiber substrate, the inner surface is more suitable for the formation of the selective layer via LBL deposition than the outer surface.     

刮刀厚度对聚酰胺正渗透复合膜性能的影响

为考察正渗透过程基膜厚度对膜水通量的作用,有效地提高膜的综合性能,采用浓度2 mol/L的NaCl作为汲取液、去离子水为原料液作为评价系统,考察了刮刀厚度不同对正渗透复合膜性能的影响。结果表明,以筛孔80μm的筛网作为支撑材料,当采用厚度为45μm的刮刀所制备的超滤膜作为支撑材料时,制备所得的正渗透复合膜性能为佳,结构参数S可低至1.086 mm;并具有最好的稳定性以及最佳的污染冲洗恢复效果。     

Effects of organic acids on the performance of cellulose triacetate forward osmosis membrane

Forward osmosis (FO) membrane performance was improved using different organic acids (formic acid, acetic acid, lactic acid) for the addition of the casting solution. Scanning electron microscope (SEM) images of all the FO CTA membranes exhibited essentially the membranes have a structure of looking like two dense skin layers and a sponge‐like supporting layer. Additionally, based on the surface roughness values analysis of Atomic Force Microscope (AFM), the membranes with lactic acid, with similar roughness to the membranes without any acid, have bigger roughness than the membranes with formic acid or acetic acid. Furthermore, the water flux of membranes with acids has been improved and the reverse salt flux decreased. The membranes with lactic acid, with an outstanding penetration performance, were utilized to test the performance when 1 mol/L sodium chloride (NaCl), magnesium chloride (MgCl₂)_, magnesium sulfate (MgSO₄), and sodium sulfate (Na₂SO₄) were, respectively, as the draw solutions. The results revealed that the membranes have a higher rejection ratio for MgSO₄. Besides, in the process of separating oil–water mixture, the membranes with the organic acids have a better separation efficiency than the membrane without any acid during FO process and the water flux recovery rate could achieve above 90% insuring the membrane anti‐fouling. POLYM. ENG. SCI., 59:E138–E145, 2019. © 2018 Society of Plastics Engineers     

Preparation of a novel poly(ether sulfone) adsorptive ultrafiltration membrane containing a crosslinked quaternary chitosan salt and chromate removal

To improve the removal performance of low‐concentration hexavalent chromium [Cr(VI)] in the ultrafiltration (UF) process, adsorptive UF membranes were prepared from suspensions consisting of poly(ether sulfone), N,N‐dimethylacetamide, poly(vinyl pyrrolidone), and crosslinked quaternary chitosan salt (CQS). The results show that the contact angle of the membrane increased from 67 to 83° when the content of CQS was changed from 0 to 10 wt %. Meanwhile, the initial rejection of bovine serum albumin decreased from 90 to 61%, and the pure water fluxes of the membranes showed no obvious change. The rejection of Cr(VI) increased from 20% to 87% when the content of CQS was changed from 0 to 10 wt % in the membrane. Adsorptive UF membranes could be generated by a 1 mol/L solution of NaCl. The adsorption data were more applicable for a pseudo‐second‐order kinetic model and the Langmuir isotherm model. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45198.     

Effects of polyethylene glycol on the structure and filtration performance of thin-film PA-Psf composite forward osmosis membranes

In forward osmosis, internal concentration polarization is related to the properties (e.g., hydrophilicity, porosity, structural resistant) of membrane support layer. In this work, polyethylene glycol with a low molecular weight of 400 Da was introduced as a support layer additive during the fabrication of thin-film polyamide-polysulfone composite forward osmosis membranes. The forward osmosis performances including water flux and reverse salt flux of the membranes were tested in the mode of AL-FS where the membrane active layer faced toward feed solution. Results showed that the addition of polyethylene glycol would reduce internal concentration polarization and improve membrane performance in forward osmosis by means of enhancing membrane hydrophilicity and changing pore morphologies of membrane support layer. The membrane prepared with 6 wt.% polyethylene glycol was found to exhibit the highest water flux of 47.4 Lm^?2h^?1 with a reverse salt flux of 7.6 gm^?2h^?1 when using DI water and 2.0 M NaCl as the feed and the draw solution, respectively, indicating an optimal polyethylene glycol dosage of 6 wt.% in this work.     

Correlation of the polymer hydrophilicity and membrane fabrication process on the properties of asymmetric membranes in a vapor‐induced phase‐inversion process

In this study, we sought a better understanding of how the hydrophilicity of a polymer affects the morphology and performance of membranes. Three types of polymer with different hydrophilicity solution systems were considered: poly(aryl ether ketone) bearing a hydroxyl group (PEK–OH‐100) with N,N ‐dimethylformamide (DMF); poly(aryl ether ketone) bearing a 50% fraction hydroxyl group with DMF, and cardo poly(aryl ether ketone) with DMF. These systems were used to investigate the evolution of the morphology and variation in performance versus a change in the hydrophilicity of the polymer. In addition, the fundamental thermodynamic influence of the solution systems on the phase‐inversion process was investigated by cloud‐point measurement and Hansen solubility parameter theory to determine the role of polymer hydrophilicity on the stability of the polymer solution in humid surroundings. The performance of the membranes was tested via testing of the pure water flux, porosity, and rejection of bovine serum albumin (BSA) with respect to variations in the polymer hydrophilicity, evaporation time, relative humidity, and molecular weight of the polymer. The resulting optimal membrane exhibited a flux of 329.3 L m^?2 h^?1 and a 99.3% rejection of BSA at a relative humidity of 90% and an evaporation time of 3 s. The hydrophilic PEK–OH‐100 membranes have promising applications in protein separation and the porous support of reverse‐osmosis membranes and so on. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44701.     

Interforce initiated by magnetic nanoparticles for reducing internal concentration polarization in CTA forward osmosis membrane

The interforce between the magnetic composite forward osmosis (FO) membranes and the magnetic draw solution was proposed to reduce the internal concentration polarization (ICP) of FO process, and realized the synergetic permeability improvement of resultant FO membranes. The key factor was the successful fabrication of the Fe₃O₄ magnetic nanoparticles (MNPs) with small‐size and narrow distribution via co‐precipitation method. The cellulose triacetate (CTA) magnetic composite FO membranes were fabricated using Fe₃O₄ as additive via in situ interfacial polymerization, and named CTA‐Fe₃O₄. Dynamic light scattering (DLS) and zeta results showed that the coated sodium oleate on the MNPs explained their reducing aggregation and the stability of various pHs. The MNPs' surface segregation during demixing process resulted in the improvement of hydrophilicity, Fe content and roughness of resultant CTA‐Fe₃O₄ composite FO membranes. Furthermore, the in situ interfacial polymerization resulted in the formation of the polyamide selective layer, and the CTA‐Fe₃O₄ membrane's N content was 11.02% to 11.12%. The permeability properties (FO and pressure retarded osmosis modules) were characterized using 1.0M NaCl and 100 mg/L Fe₃O₄ as draw solutions, respectively. The results indicated that the higher concentration of MNPs supplied more interforce and better FO permeability properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44852.