Potential of DMSO as greener solvent for PES ultra‐ and nanofiltration membrane preparation

In this article, the performance of polyethersulfone (PES) ultra‐ and nanofiltration membranes, prepared with the non‐toxic solvent dimethyl sulfoxide (DMSO), was investigated. The membranes were prepared by immersion precipitation via phase inversion. Experimental results proved that DMSO is a better alternative to N‐methyl‐2‐pyrrolidone (NMP) as solvent for PES ultrafiltration membranes as the membranes had a higher permeability and rejection of bovine serum albumin (BSA). An explanation was found based on experimental cloud point data and scanning electron microscopy images showing the morphology. The rejection of BSA and rose Bengal (RB) was proportional to the polymer concentration. On the contrary, the permeability decreased with increasing polymer concentration. For a casting thickness of 250 µm, an optimal balance between permeability and rejection of macromolecules for ultrafiltration was found at 24 wt % PES. The permeability was inversely proportional to the casting thickness, but a small decrease in rejection was observed when lowering the thickness. A good balance between permeability and rejection of RB was found, using a reference nanofiltration membrane of 28.5 wt % PES with 150 µm casting thickness. This membrane achieved a RB rejection of 95.3% and a pure water flux of 2.03 L m^?2 h^?1 bar^?1. The membrane thickness and polymer concentration did not have a clear influence on the hydrophilicity of the membranes. It can be concluded that DMSO is a benign alternative as compared to traditional solvents such as NMP and also results in better PES membrane performances. DMSO is a perfectly suitable solvent for ultrafiltration applications and has potential to be used for nanofiltration applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46494.     

High‐performance composite nanofiltration membranes fabricated via ternary mixture: Complementary preponderance of the fluorine‐containing monomer 2,2′‐bis(1‐hydroxyl‐1‐trifluoromethyl‐2,2,2‐triflutoethyl)‐4,4′‐methylene dianiline and the rigid monomer bisphenol F

In a previous study, we proved that tailoring the polyamide backbone stiffness is an effective way to fabricate high‐performance polyamide nanofiltration (NF) membranes. However, in the previous study, we mainly focused on the flat membrane and did not consider its chlorine tolerance. In this study, by regulating the aqueous‐phase compositions in the interfacial polymerization process, chlorine tolerance on NF hollow‐fiber membranes was endowed while the membrane performance stayed high. The experimental results show that when the ratio of Piperazine (PIP)–bisphenol F (BPF)/2,2′‐bis(1‐hydroxyl‐1‐trifluoromethyl‐2,2,2‐triflutoethyl)‐4,4′‐methylene dianiline (BHTTM) was 5:1:4, the NF membrane possessed a permeate flux of 21.0 L m^?2 h^?1 bar^?1 and an Na₂SO₄ rejection up to 90.0%. X‐ray photoelectron spectroscopy analysis also confirmed that the polymerization degree of the PIP–BPF–BHTTM NF membrane was the highest. Moreover, the NF membrane could tolerate active chlorine to over 10,000 ppm h Cl. After the active chlorine treatment, the permeate flux increased over 30.0 L m^?2 h^?1 bar^?1, and the Na₂SO₄ rejection was about 90.0%. Although the PIP–BHTTM NF membrane also possessed good chlorine tolerance, its permeate flux (after active chlorine treatment) was only 60% of that of the PIP–BPF–BHTTM NF membrane. Therefore, the PIP–BPF–BHTTM NF membrane possessed a combination of high flux and high chlorine tolerance and showed good potential in water treatment in rigorous environments. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46482.     

Engineering design of outer‐selective tribore hollow fiber membranes for forward osmosis and oil‐water separation

Outer‐selective thin‐film composite (TFC) hollow fiber membranes offer advantages like less fiber blockage in the feed stream and high packing density for industrial applications. However, outer‐selective TFC hollow fiber membranes are rarely commercially available due to the lack of effective ways to remove residual reactants from fiber's outer surface during interfacial polymerization and form a defect‐free polyamide film. A new simplified method to fabricate outer‐selective TFC membranes on tribore hollow fiber substrates is reported. Mechanically robust tribore hollow fiber substrates containing three circular‐sector channels were first prepared by spinning a P84/ethylene glycol mixed dope solution with delayed demixing at the fiber lumen. The thin wall tribore hollow fibers have a large pure water permeability up to 300 L m^?2 h^?1 bar^?1. Outer‐selective TFC tribore hollow fiber membranes were then fabricated by interfacial polymerization with the aid of vacuum sucking to ensure the TFC layer well‐attached to the substrate. Under forward osmosis studies, the TFC tribore hollow fiber membrane exhibits a good water flux and a small flux difference between active‐to‐draw (i.e., the active layer facing the draw solution) and active‐to‐feed (i.e., the active layer facing the feed solution) modes due to the small internal concentration polarization. A hyperbranched polyglycerol was further grafted on top of the newly developed TFC tribore hollow fiber membranes for oily wastewater treatment. The membrane displays low fouling propensity and can fully recover its water flux after a simple 20‐min water wash at 0.5 bar from its lumen side, which makes the membrane preferentially suitable for oil‐water separation. © 2015 American Institute of Chemical Engineers AIChE J, 61: 4491–4501, 2015     

Surface modification of polyacrylonitrile based ultrafiltration membrane

Ultrafiltration membrane based on polyacrylonitrile prepared by phase inversion method using zinc chloride as an additive showed more than 90% rejection for BSA and 90–110 lm^?2 h^?1 water flux. The surface modification of this membrane was studied using ethanolamine, triethylamine, sodium hydroxide, and potassium hydroxide solutions. The effect of base treatment time and temperature on water flux and rejection was investigated. The membranes exhibited swelling by NaOH treatment followed by deswelling by HCl post‐treatment, similar to pH responsive membranes. The treatment by organic as well as inorganic bases improved water flux with a slight lowering in BSA rejection by dead‐end mode type treatment. A 230% increase in water flux was achieved by sodium hydroxide treatment in crossflow mode without a noticeable pore swelling by SEM. The contact angle of the modified membranes was decreased as compared to the unmodified one indicating appreciable surface modification. As the treatment time or temperature increased, the ESCA analysis showed increased population of Na‐carboxylate groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4378–4385, 2006     

ETA‐m‐PAN and its Composite Membrane with High Performance Prepared by In Situ Modification/NIPS Principle

Ethanolamine‐modified polyacrylonitrile (ETA‐m‐PAN) membrane is prepared by in situ modification integrated with a nonsolvent‐induced phase separation method for the first time. The results reveal that both the morphology and the separation performance of the modified membrane change greatly with condition parameters. The membrane formation mechanism is carefully investigated, which is related to the change in the molecular structure and hydrophilic property of ETA‐m‐PAN. The cross‐linked structure leads to the formation of ETA‐m‐PAN spongy membrane. The optimized condition parameters are determined by permeability‐selectivity analysis. Furthermore, the composite membrane with ETA‐m‐PAN as the selective layer is prepared by a dual‐casting method. The obtained membrane shows a good property, flux of 650L m^?2 h^?1 bar^?1, 82% BSA rejection, and 84% water flux recovery ratio. This work demonstrates the great potential of this integrated method for new membrane preparation.     

Preparation of a polyimide nanofiltration membrane for lubricant solvent recovery

Polyimide (PI) membrane has been proven to be an efficient approach for solvent recovery. However, the inherent fragility of the PI membrane limits the range of separation conditions and process economics. In this study, copolyimides were synthesized from 3,3′,4,4′‐benzophenone–tetracarboxylic dianhydride (BTDA) and 4,4′‐biamino‐3,3′‐dimethyldiphenyl–methane (DMMDA) by chemical imidization in a two‐step procedure. Then, a PI nanofiltration (NF) membrane was prepared through a phase‐inversion process for solvent recovery from lube oil filtrates. The results indicated that the immersion of the PI (BTDA–DMMDA) NF membrane in a 1,6‐diaminohexane/ethanol crosslinking agent solution carried on the chemical crosslinking modification, which could effectively improve the solvent resistance of the NF membrane. Moreover, the addition of inorganic salt in the polymer solution further enhanced the solvent resistance and pressure resistance of the membrane, which was favorable for the solvent recovery. The lubricant rejection was above 93%, and the solvent flux was about 30 L m^?2 h^?1 with the NF membrane prepared in optimum conditions, and this membrane showed great potential for future development in the application of solvent recovery from lube oil filtrates. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40338.     

Preparation of thin film nanocomposite membranes with surface modified MOF for high flux organic solvent nanofiltration

Preparation of defect‐free and optimized thin film nanocomposite (TFN) membranes is an effective way to enhance the process of organic solvent nanofiltration. However, it still remains a great challenge due to poor filler particle dispersibility in organic phase and compatible issue between fillers and polymers. Aiming at these difficulties, UiO‐66‐NH₂ nanoparticles were surface modified with long alkyl chains and used in the preparation of TFN membranes. As a result, defect‐free TFN membranes with ultrathin MOF@polyamide layer were successfully prepared benefited from the improved particle dispersibility in n‐hexane. Significant enhancement was found in methanol permeance after nanoparticle incorporation, without comprising the tetracycline rejection evidently. Especially, the novel TFN membrane prepared with organic phase solution containing 0.15% (w/v) modified UiO‐66‐NH₂ nanoparticles showed a superior methanol permeance of 20 L·m^?2·h^?1·bar^?1 and a tetracycline rejection of about 99%, which is appealing to the application in pharmaceutical industry for example. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1303–1312, 2017     

Highly improved permeation property of thin-film-composite polyamide membrane for water desalination

Thin-film-composite (TFC) polyamide membranes with flux-enhancement were prepared by the interfacial polymerization of m-phenylenediamine with trimesoyl chloride on porous polysulfone support. The addition of 1,3-propanesultone (PS) in the organic phase is used to influence the interfacial polymerization process and the morphology of polyamide layer to improve water flux. FTIR, ¹H NMR and UV spectra were performed to investigate the effect of PS on interfacial polymerization process. In order to study the forming mechanism of TFC membrane, the resulting TFC membranes were characterized by SEM, AFM, ATR-FTIR, XPS, as well as static contact angle. In comparison with conventional polyamide membrane, the TFC membranes fabricated with PS as the additive exhibit much more improved water flux without NaCl rejection decreasing. Notably, the optimal TFC membrane with 0.04% (wt/v) PS as the additive in organic phase shows the best performance with a NaCl rejection of 99.39% and a water flux of 48.57 L m^?2 h^?1 at 1.55 MPa, which has increased 41% compared to the value of the conventional TFC membrane.     

Optimization of water flux and salt rejection properties of polyamide thin film composite membranes

Optimizing synthesis factors of polyamide top layers is an important requirement in the design of thin film composite (TFC) membranes. In this research, the top layer fabrication method (conventional, heat curing, and spin coating), type of acid acceptor (sodium carbonate, sodium hydroxide, and triethylamine), type of organic phase solvent (hexane, heptane, and mixed hexane/heptane), and concentration of surfactant sodium dodecyl sulfate (0, 0.5, and 1 wt %) are selected as the control parameters of this synthesis and optimized using the Taguchi approach. The analysis of variance shows that the layer fabrication method is the most influential parameter on water flux and salt (NaCl) rejection of TFCs. Furthermore, although the type of organic solvent has not a significant contribution to the water flux, it is another significant factor affecting the rejection. The optimized membrane is then used to construct structure–property relationships and to understand the influence of each individual factor on the desalination performance. Accordingly, a TFC membrane with the top layer fabricated by the heat curing method, in the presence of Na₂CO₃ as the acid acceptor, hexane as the organic phase solvent and 0.5 wt % of the surfactant is prepared that shows water permeance of 2.73 L m⁻² h⁻¹ bar⁻¹ and NaCl rejection of 98.1%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48858.     

Thin-film composite crosslinked polythiosemicarbazide membranes for organic solvent nanofiltration (OSN)

In this work we report a new class of solvent stable thin-film composite (TFC) membrane fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate that exhibits superior stability compared with other solvent stable polymeric membranes reported up to now. Integrally skinned asymmetric PTSC membranes were prepared by the phase inversion process and crosslinked with an aromatic bifunctional crosslinker to improve the solvent stability. TFC membranes were obtained via interfacial polymerization using trimesoyl chloride (TMC) and diaminopiperazine (DAP) monomers. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement.The membranes exhibited high fluxes toward solvents like tetrahydrofuran (THF), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) ranging around 20 L/m² h at 5 bar with a molecular weight cut off (MWCO) of around 1000 g/mol. The PTSC-based thin-film composite membranes are very stable toward polar aprotic solvents and they have potential applications in the petrochemical and pharmaceutical industry.     

Highly efficient removal of phenol from aqueous solutions using graphene oxide/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> composite membrane

To achieve superior separation performance in the phenol aqueous solutions treatment, a novel graphene oxide/Al₂O₃ composite membrane was prepared by a spin coating process. The microstructure measurement shows that the composite membrane has a multilayer structure and graphene oxide has been tightly coated on the surface of the Al₂O₃ membrane interlayer homogeneously. During the treatment of phenol aqueous solutions, the permeation flux and phenol rejection of the composite membrane were investigated. The results show the permeation flux of the membrane is about 1.153 L m^?2 h^?1 bar^?1 and the phenol rejection of the membrane increases to 99.9% when the phenol concentration is 0.01 g L^?1. The high phenol rejection of the composite membrane is mainly attributed to the physical sieving, the solution–diffusion effect and the hydrophobic nature of graphene oxide. All these results indicate the GO/Al₂O₃ composite membrane is a suitable material for the removal of phenol from aqueous solutions in environmental pollution management.     

Taurine as an additive for improving the fouling resistance of nanofiltration composite membranes

A hydrophilic compound, taurine, was investigated as an additive in the interfacial polymerization between piperazine (PIP) and trimesoyl chloride (TMC) to prepare thin‐film composite (TFC) membranes. The resulting membranes were characterized by X‐ray photoelectron spectroscopy and attenuated total reflectance–Fourier transform infrared spectroscopy. The morphology and hydrophilicity of the membranes were investigated through scanning electronic microscopy and water contact angle measurements. The separation performance of the TFC membranes was investigated through water flux and salt rejection tests. The protein‐fouling resistance of the films was evaluated by water recovery rate measurements after the treatment of bovine serum albumin. The membrane containing 0.2 wt % taurine showed the best performance of 92% MgSO₄ rejection at a flux of 31 L m^?2 h^?1 and better antifouling properties than the PIP–TMC membranes. An appropriately low concentration of taurine showed the same MgSO₄ rejection as the PIP–TMC membranes but a better fouling resistance performance. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41620.     

Thermodynamics and kinetics control of support layer synthesis for enhanced thin film composite membrane performance

The desalination performance of a thin film composite (TFC) membrane hinges highly on the surface characteristics of support membrane. In this study, good wettability, regular pore size, and moderate roughness were identified as the critical surface properties of support membrane in forming a defect‐free, uniform, and structurally stable polyamide film. These features were tailored by adjusting the thermodynamics and kinetics properties of the polymer solution via polysulfone (PSf)/polyvinylpyrrolidone (PVP) ratio as well as using N,N‐dimethylacetamide (DMAc) and N,N‐dimethylformamide as co‐solvent. It was found that the membrane formation was controlled kinetically by altering the PSf/PVP ratio but thermodynamically by using co‐solvent. The TFC membrane with better desalination performance was achieved with the support membrane prepared at PSf/PVP ratio of 0.941 without any co‐solvent. The resulting TFC membrane attained the highest permeability ratio of 0.691 bar^?1 for water/NaCl filtration in this study. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45802.     

Investigation of the effect of tetrahydrofuran and acetone as cosolvents in acrylonitrile–butadiene–styrene–based nanofiltration membranes

In this study, novel nanofiltration membranes were prepared with acrylonitrile–butadiene–styrene (ABS)–poly(ethylene glycol)–N,N ‐dimethylacetamide–[tetrahydrofuran (THF)–acetone] as a cosolvent. All of the membranes were prepared by the phase‐inversion method and a casting solution technique. The effects of the cosolvent concentration in the casting solution and the evaporation time before the immersion/precipitation step on the membrane performance and properties were investigated. The prepared membranes were characterized through their permeation flux, salt rejection, and phase‐inversion time values. The salt rejection was increased from 53% for the bare ABS membrane to 73% for the membrane prepared with 40 wt % THF as a cosolvent. The water flux was decreased from 4345 to 1121 cc m^?2 h^?1 with the addition of THF to the casting solution. The addition of acetone to the casting solution improved the water flux from 4345 to 5607 cc m^?2 h^?1 and reduced the salt rejection from 53 to 36%. The evaporation time of THF and acetone led to similar effects on flux and rejection. However, with evaporation time, membranes prepared with acetone were denser than those prepared with THF; this was due to the lower boiling point and higher boiling rate of acetone at the same temperatures. This resulted in greater effects on the ABS performance and structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44993.     

Polyamide composite membranes for enhanced organic solvent nanofiltration performance by metal ions assisted interfacial polymerization method

Herein, thin-film composite membranes consisting of poly(m-phenyleneisophthalamide) substrate and polyamide active layer were constructed by transition metal ion-assisted interfacial polymerization method. As compared to the traditional polyamide membranes, a much thinner polyamide layer (33 vs. 200 nm) can be synthesized with higher permeance (3.2 vs. 0.62 L m⁻² h⁻¹ bar⁻¹) in the organic solvent nanofiltration. Similarly, the prepared membranes maintained a high rejection (>99%) for various dyes. Optimal membranes prepared by using Co²⁺ exhibited strong tolerance to various organic solvents with good long-term stability. Positron annihilation spectroscopy and other characterization methods were used to investigate the relationships between the membrane microstructures and the enhanced separation performance. Based on molecular dynamics simulation, it was found that the diffusion coefficient of polyethyleneimine monomer decreased by about 18 times after adding Co²⁺ to the aqueous solution (forming coordination interaction). This procedure has great potential and sustainability for practical organic solvent nanofiltration applications.     

Influence of metal salts in reaction medium on performance enhancement of novel aliphatic–aromatic-based polyamide thin-film composite osmosis membranes

In this study, we report an easy and novel way to develop high flux aliphatic–aromatic-based thin-film composite (TFC) polyamide osmosis membranes by addition of inorganic metal salts with amine reactants in the reaction system of polyethylene imine (PEI) and 1,3-benzene dicarbonyl chloride. Inorganic metal salts like CuSO₄, NiSO₄, MgSO₄, and Al₂(SO₄)₃ added to block some of the amine groups of PEI through complexation which in turn changes the polycondensation reaction kinetics of amine acid chloride reaction. The prepared membranes were characterized using water contact angle and atomic force microscopy studies and the performances were evaluated both in reverse osmosis and forward osmosis mode. In presence of metal salts in reaction interface, the performance of TFC membranes was greatly enhanced and the optimum metal salt concentration was identified for individual metal salts for maximum performance enhancement. The effects of different anions for same metal ion and different molecular weight of PEI were evaluated on composite polyamide membrane performances. Water permeability (flux) of 63.48 L m^?2 h^?1 was achieved upon inorganic salt addition compared to the unmodified TFC membranes with flux of 42.1 L m^?2 h^?1 at similar salt rejection of ~95%. Based on the new findings, a conceptual model was proposed to explain the role of metal ion in amine solution on the resulting characteristics of aromatic–aliphatic type polyamide–polysulfone composite membrane.     

Fabrication of efficient pervaporation desalination membrane by reinforcement of poly(vinyl alcohol)–silica film on porous polysulfone hollow fiber

Pervaporation membrane technology is commercially successful in the dehydration of organic solvents, and the technology has potential for seawater desalination with high recovery because of its capability to treat highly saline water. But to make the technology advantageous over the other available membrane desalination technologies in terms of productivity flux without additional energy cost, the selective barrier layer is required to be extremely thin, defect‐free, hydrophilic, and selective to water. In this work, we prepared an efficient membrane by reinforcing a highly water‐permeable but continuous barrier layer of poly(vinyl alcohol)–silica (PVA‐SiO₂) hybrid material on porous polysulfone hollow fibers. The PVA‐SiO₂ in acidified and hydrated ethanol was aged at room temperature for a period to allow solvent evaporation to obtain the solution concentration desired for the reinforcement. The reinforced hollow fiber membrane with optimal PVA‐SiO₂ barrier layer thickness exhibited a performance with a flux of 20.6 L m^?2 h^?1 and 99.9% salt rejection from a saline feed of 2000 ppm NaCl at 333 K. The effects of PVA‐SiO₂, temperature, and feed salinity on the pervaporation performance of the membrane were also studied. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45718.     

High-flux and solvent-selective membranes with aromatic functionalities and dual-layer structures

Efficient separation of aromatic-aliphatic hydrocarbon mixtures has long been an important topic in chemical industries. Organic nanofiltration (OSN) has been revealing great promise in separating solvent mixtures that has not been effectively resolved by the state-of-the-art technologies. Herein, novel OSN membranes are designed for the separation of toluene and n-heptane. Polyamide active layer with diaminonaphthalene as the aqueous phase monomer is prepared by interfacial polymerization for the first time. The addition of polydimethylsiloxane gutter layer, as well as the combination of spin coating technique and macroporous substrate, renders the membranes with loose and defect-free architectures. The as-designed membranes achieve a rather high selectivity of toluene over n-heptane (>4) together with ultra-high toluene permeance (>180 L m^?2 h^?1 bar^?1). These membranes also present excellent stability in the long-term operation.     

Effects of mixed solvents and PVDF types on performances of PVDF microporous membranes

Polyvinylidene fluoride (PVDF) microporous flat membranes were cast with different kinds of PVDFs and four mixed solvents [trimethyl phosphate (TMP)–N,N‐dimethylacetamide (DMAc), triethyl phosphate (TEP)–DMAc, tricresyl phosphate (TCP)–DMAc, and tri‐n‐butyl phosphate (TBP)–DMAc]. The effects of different commercial PVDFs (Solef® 1015, FR 904, Kynar 761, Kynar 741, Kynar 2801) on membrane morphologies and membrane performances of PVDF/TEP–DMAc/PEG200 system were investigated. The membrane morphologies were examined by scanning electron microscopy (SEM). The membrane performances in terms of pure water flux, rejection, porosity, and mean pore radius were measured. The membrane had the high flux of 143.0 ± 0.9 L m^?2 h^?1 when the content of TMP in the TMP–DMAc mixed solvent reached 60 wt %, which was 2.89 times that of the membrane cast with DMAc as single solvent and was 3.36 times that of the membrane cast with TMP as single solvent. Using mixed solvent with different solvent solubility parameters, different morphologies of PVDF microporous membranes were obtained. TMP–DMAc mixed solvent and TEP–DMAc mixed solvent indicated the stronger solvent power to PVDF due to the lower solubility parameter difference of 1.45 MPa^1/2 and the prepared membranes showed the faster precipitation rate and the higher flux. The less macrovoids of the membrane prepared with TEP (60 wt %)–DMAc (40 wt %) as mixed solvent contributed to the higher elongation ratio of 96.61% ± 0.41%. Therefore, using TEP(60 wt %)–DMAc (40 wt %) as mixed solvent, the casting solution had the better solvent power to PVDF, and the membrane possessed the excellent mechanical property. The microporous membranes prepared from casting solutions with different commercial PVDFs exhibited similar morphology, but the water flux increased with the increment of polymer solution viscosity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Codeposition of catechol–polyethyleneimine followed by interfacial polymerization for nanofiltration membranes with enhanced stability

Thin‐film composite (TFC) nanofiltration (NF) membranes were fabricated via the codeposition of catechol (CCh) and polyethyleneimine (PEI) followed by subsequent interfacial polymerization with trimesoyl chloride (TMC) on the surface of polysulfone ultrafiltration substrates. The detailed structures and surface properties were characterized by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, ζ potential analysis, and water contact angle measurement. The surface properties, including the roughness, hydrophilicity, surface potential, and NF performances, were facilely tuned through variation of the codeposition time of CCh–PEI for the prepared TFC membranes. The optimized membrane achieved a high rejection (ca. 93%) of MgCl₂ with a flux of around 31 L m^?2 h^?1 under 0.7 MPa. The results also reveal that the codeposition process endowed the final membranes with much better structural stability in alcohol and improved chlorine resistance compared to commonly interfacial polymerized ones with PEI and TMC. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45422.