Salt‐leaching technique for the synthesis of porous poly(2,5‐benzimidazole) (ABPBI) membranes for fuel cell application

The first instance of synthesizing porous poly(2,5‐benzimidazole) (ABPBI) membranes for high‐temperature polymer electrolyte membrane fuel cells (HT‐PEMFCs), using solvent evaporation/salt‐leaching technique, is reported herein. Various ratios of sodium chloride/ABPBI were dissolved in methanesulfonic acid and cast into membranes by solvent evaporation, followed by porogen (salt) leaching by water washing. The membranes were characterized using SEM, FTIR, TGA, and DSC. The proton conductivity, water and acid uptake of the membranes were measured and the chemical stability was determined by Fenton's test. SEM images revealed strong dependence of sizes and shapes of pores on the salt/polymer ratios. Surface porosities of membranes were estimated with Nis Elements‐D software; bulk porosities were measured by the fluid resaturation method. Thermogravimetric analysis showed enhanced dopant uptake with introduction of porosity, without the thermal stability of the membrane compromised. Incorporating pores enhanced solvent uptake and retention because of capillarity effects, enhancing proton conductivities of PEMs. Upon acid doping, a maximum conductivity of 0.0181 S/cm was achieved at 130 °C for a porous membrane compared with 0.0022 S/cm for the dense ABPBI membrane at the same temperature. Results indicated that with judicious optimization of porogen/polymer ratios, porous ABPBI membranes formed by salt‐leaching could be suitably used in HT‐PEMFCs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45773.     

A copolymer of poly[2,2′‐(m‐phenylene)‐5,5′‐ bibenzimidazole] and poly(2,5‐benzimidazole) for high‐temperature proton‐conducting membranes

A novel copolymer of polybenzimidazoles was prepared by copolymerization of 3,3′‐diaminobenzidine tetrahydrochloride, 3,4‐diaminobenzoic acid and isophthalic acid in polyphosphoric acid at 200 °C. The polymerization could be performed within 90–110 min with the assistance of microwave irradiation. The solubility of the copolymer obtained in N,N‐dimethylacetamide (DMAc) was improved compared with those of poly[2,2′‐(m‐phenylene)‐5,5′‐bibenzimidazole] and poly(2,5‐benzimidazole). Thus copolymer membranes could be readily prepared by dissolving the copolymer powders in DMAc with refluxing under ambient pressure. The decomposition temperature of the copolymer was about 520 °C in air according to thermogravimetric analysis data. The proton conductivity and mechanical strength of the phosphoric acid‐doped copolymer membranes were investigated at elevated temperatures. A conductivity of 0.09 S cm^?1 at 180 °C and a tensile stress at break of 5.9 MPa at 120 °C were achieved for the acid‐doped copolymer membranes by doping acids in a 75 wt% H₃PO₄ solution. Copyright © 2010 Society of Chemical Industry     

Synthesis and characterization of POSS hybrid organogels using Menschutkin quaternization chemistry

The present research describes a series of organic–inorganic hybrid gels based on polystyrene and polyhedral oligomeric silsesquioxanes (POSSs) prepared using free radical copolymerization and Menschutkin chemistry techniques. In the first step, poly(styrene‐co‐chloromethylstyrene) is readily achieved by thermally initiated radical copolymerization and the subsequently obtained copolymer reacts with diethanolamine functional POSS nanoparticles which are employed as the crosslinker. The resulting hybrid network possesses ionic moieties and inorganic POSS nanoparticles. The POSS‐containing hybrid gels exhibit excellent organic solvent absorption and show good mechanical behaviour. Gel containing 0.8 × 10^?3 mmol of POSS(DEA)₈ (DEA, diethanolamine) reached the highest swelling ratio; hence, the corresponding gel can absorb organic solvent up to 20× its weight. The rate constant, coefficients and diffusional behaviour of hybrid organogels in organic solvent were examined as well. The organic solvent intake of the hybrid gel follows a non‐Fickian type diffusion. © 2018 Society of Chemical Industry     

Electrochemical synthesis and In situ spectroelectrochemistry of conducting NMPy‐TiO2 and ZnO polymer nanocomposites for Li secondary battery applications

Poly(N‐methylpyrrole) (PNMPy), poly(N‐methylpyrrole‐TiO₂) (PNMPy‐TiO₂), and poly (N‐methylpyrrole‐ZnO) (PNMPy‐ZnO) nanocomposites were synthesized by in situ electropolymerization for cathode active material of lithium secondary batteries. The charge–discharging behavior of a Li/LiClO₄/PNMPy battery was studied and compared with Li/LiClO₄/PNMPy‐nanocomposite batteries. The nanocomposites and PNMPy films were characterized by cyclic voltammetry, in situ resistivity measurements, in situ UV–visible, and Fourier transform infra‐red (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The differences between redox couples (ΔE) were obtained for polymer nanocomposites and PNMPy films. During redox scan, a negative shift of potential was observed for polymer nanocomposite films. Significant differences from in situ resistivity of nanocomposites and PNMPy films were obtained. The in situ UV–visible spectra for PNMPy and polymer nanocomposite films show the intermediate spectroscopic behavior between polymer nanocomposites and PNMPy films. The FTIR peaks of polymer nanocomposite films were found to shift to higher wavelengths in PNMPy films. The SEM and TEM micrographs of nanocomposite films show the presence of nanoparticle in PNMPy backbone clearly. The result suggests that the inorganic semiconductor particles were incorporated in organic conducting PNMPy, which consequently modifies the properties and morphology of the film significantly. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41526.     

Synthesis and characterization of poly(p‐phenylene)‐graft‐poly(ε‐caprolactone) copolymers by combined ring‐opening polymerization and cross‐coupling processes

2,5‐Dibromo‐1,4‐(dihydroxymethyl)benzene was used as initiator in ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate (Sn(Oct)₂) catalyst. The resulting poly(ε‐caprolactone) (PCL) macromonomer, with a central 2,5‐dibromo‐1,4‐diphenylene group, was used in combination with 1,4‐dibromo‐2,5‐dimethylbenzene for a Suzuki coupling in the presence of Pd(PPh₃)₄ as catalyst or using the system NiCl₂/bpy/PPh₃/Zn for a Yamamoto‐type polymerization. The poly(p‐phenylenes) (PPP) obtained, with PCL side chains, have solubility properties similar to those of the starting macromonomer, ie soluble in common organic solvents at room temperature. The new polymers were characterized by ¹H and ¹³C NMR and UV spectroscopy and also by GPC measurements. The thermal behaviour of the precursor PCL macromonomer and the final poly(p‐phenylene)‐graft‐poly(ε‐caprolactone) copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry analyses and compared. Copyright © 2004 Society of Chemical Industry     

Synthesis and characterization of polymers derived from selenophene

The synthesis of poly(2,5‐selenophen‐oxo‐1,4‐phenylen‐selenide‐1,4‐phenylene‐oxo) (I) and poly(2,5‐selenophen‐oxo‐1,4‐phenylen‐diselenide‐1,4‐phenylen‐oxo) (II) by reaction of 2,5‐bis(1,4‐bromo‐phenylen‐oxo‐)‐selenophene with sodium selenide or diselenide, respectively, using dimethylformamide as solvent, is described. Both monomers and polymers were characterized by elemental analysis, melting point, and FTIR spectroscopy. Polymers I and II were doped with iodine and SbF₅ and characterized by SEM and XPS. Also, the conductivity and the T_g values were determined. For both polymers the best doping agent was iodine, although polymer II always presented higher conductivity, reaching values of about 6 · 10^?9 S · cm^?1. The T_g values suggest a likely crosslinking of the chains in polymer II when doped with SbF₅. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2019–2026, 2001     

Gas permeation properties of poly(2,5‐benzimidazole) derivative membranes

In this article, three novel polymers based on poly(2,5‐benzimidazole) (ABPBI) were synthesized by introducing propyl, isobutyl or n‐butyl groups to its side chain through an alkyl substitution reaction. FTIR and ¹³C NMR were applied to confirm the formation of corresponding chemical groups. Their physical properties including crystallinity, thermal stability, mechanical strength, and micro‐morphology were also characterized. Their solubility in common solvents were also tested to see if the modification will bring any improvement. Gas permeation properties of three derivative membranes prepared by a casting and solvent‐evaporation method were tested with pure gases including H₂, N₂, O_2, CH₄, and CO₂. It has been revealed that gas with a smaller molecular size owned a larger permeability. This means gas permeation in all prepared membranes should be diffusivity selective. Among all three modified ABPBI membranes, isobutyl substitution modified ABPBI (IBABPBI) showed the best selectivity of H₂ over other gases such as N₂ (～185) and CO₂ (～6.3) with a comparable permeability (～9.33 barrer) when tested at 35°C and 3.0 atm. Testing temperature increase facilitated gas permeation for all three membranes obviously; while in term of gas selectivity temperature increase showed diverse alteration because it brought variable impact on gas solubility of different gases. Even so, IBABPBI membrane still owned acceptable selectivity of H₂ over N₂ (～118) and CO₂ (～6.3) with an almost doubled permeability (～17.5 barrer) when tested at 75°C and 3.0 atm. Additional tests showed that running at high pressure did not bring any obvious deterioration to gas separation performance of IBABPBI membrane. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40440.     

Copolymers of Poly(2,5‐benzimidazole) and Poly[2,2′‐(p‐phenylene)‐5,5′‐bibenzimidazole] for High‐Temperature Fuel Cell Applications

Copolymers of poly(2,5‐benzimidazole) (ABPBI) and poly[2,2′‐(p‐phenylene)‐5,5′‐bibenzimidazole] (pPBI) were synthesized for use as fuel cell membranes to take advantage of the properties of both constituents. The composition of the copolymers were controlled by changing the feed ratio of 3,4‐diaminobenzoic acid and terephthalic acid with 3,3′‐diaminobenzidine in the polycondensation reaction. The copolymer membranes showed higher conductivities, better mechanical properties, and larger acid absorbing abilities than commercial poly[2,2′‐(m‐phenylene)‐5,5′‐bibenzimidazole] membranes.

     

Physical and electrochemical characterizations of poly(vinylidene fluoride‐co‐hexafluoropropylene)/SiO2‐based polymer electrolytes prepared by the phase‐inversion technique

Highly porous poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVdF–HFP)‐based polymer membranes filled with fumed silica (SiO₂) were prepared by a phase‐inversion technique, and films were also cast by a conventional casting method for comparison. N‐Methyl‐2‐pyrrolidone as a solvent was used to dissolve the polymer and to make the slurry with SiO₂. Phase inversion occurred just after the impregnation of the applied slurry on a glass plate into flowing water as a nonsolvent, and then a highly porous structure developed by mutual diffusion between the solvent and nonsolvent components. The PVdF–HFP/SiO₂ cast films and phase‐inversion membranes were then characterized by an examination of the morphology, thermal and crystalline properties, absorption ability of an electrolyte solution, ionic conductivity, electrochemical stability, and interfacial resistance with a lithium electrode. LiPF₆ (1M) dissolved in a liquid mixture of ethylene carbonate and dimethyl carbonate (1:1 w/w) was used as the electrolyte solution. Through these characterizations, the phase‐inversion polymer electrolytes were proved to be superior to the cast‐film electrolytes for application to rechargeable lithium batteries. In particular, phase‐inversion PVdF–HFP/SiO₂ (30–40 wt %) electrolytes could be recommended to have optimum properties for the application. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 140–148, 2006     

Phase relationships of rigid rod polymer/flexible coil polymer/solvent ternary systems

Phase diagrams of two types of rigid rod polymer/flexible coil polymer/methanesulfonic acid (MSA) ternary systems were determined by polarized optical microscopy at ambient conditions. The rigid rod polymer is a wholly aromatic high temperature resistant (no measurable T_g) poly (p-phenylenebenzobisthiazole) (PPBT). One of the flexible coil polymers is a wholly aromatic high temperature resistant poly (2,5′(6′) benzimidazole) (ABPBI), the other is a thermoplastic poly[2,2′ -(1–4-phenylene)-6,6′ -bis (3-phenyl-quinoxaline)] (PPQ) with T_g of 359°C. The solvent is methane-sulfonic acid (MSA). The experimentally determined critical concentration points, C_cr, are in excellent agreement with Flory's recent theory. Total phase segregation between the polymer pair in ternary solution was predicted and observed at C > C_cr. Different decomposition mechanisms of phase separation were observed as a function of concentration.     

The dominant factor for mechanical property of polyimide films containing heterocyclic moieties: In‐plane orientation,crystallization, or hydrogen bonding

Crystallization, in‐plane orientation, and hydrogen bonding interactions are three vital factors for enhancing mechanical properties of polyimide (PI) films. However, which is the dominant factor? In this study, three PI films containing heterocyclic moiety, poly(benzoxazole‐imide), poly(benzimidazole‐imide), and poly(pyrimidine‐imide) were chosen to comparative study. The crystallinity of poly(benzoxazole‐imide), poly(benzimidazole‐imide), and poly(pyrimidine‐imide) PI films are 36, 24, and 15%, respectively. The results of small angle X‐ray scattering indicate poly(benzoxazole‐imide) and poly(benzimidazole‐imide) films show periodical lamellar structures, while poly(pyrimidine‐imide) shows no long period due to low crystallinity. In‐plane orientation (P₂₀₀) is calculated from polarized attenuated total reflection (ATR)‐Fourier transform infrared and refractive indices. The order of in‐plane orientation is poly(benzimidazole‐imide) < poly(benzoxazole‐imide) < poly(pyrimidine‐imide). Hydrogen bonding interactions, which restrict chain motion and hinder spontaneous in‐plane orientation, are only formed in poly(benzimidazole‐imide). The relationship between mechanical properties and three influence factors are discussed, and the order of influence extent for mechanical properties of PI films is hydrogen bonding interactions < degree of crystallization < in‐plane orientation. Two structure models for PI films are proposed in order to further confirm the dominant effect of in‐plane orientation on the mechanical properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44000.     

Dielectric and gas transport properties of the films of thermally stable poly(arylene ether ketone)s containing content‐tunable benzimidazole moiety

A series of thermally stable poly(arylene ether ketone)s (PAEKs) bearing benzimidazole structure in the main chains, named poly(arylene ether ketone‐benzimidazole)s (PAEK‐BIs), were directly synthesized by polycondensation of dimethyl bisphenol, dibenzimidazole bisphenol, and difluorobenzophenones. By systematically varying the amount ratio of two kind of bisphenols, the content of benzimidazole moiety in the backbone was controlled straightforwardly. The prepared amorphous polymers were characterized in terms of Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, thermal, dielectric, and gas transport properties. Evaluation of solubility reveals that PAEK‐BIs with >60% content of benzimidazole units could be soluble in commonly used organic solvents. Also polymers containing content‐tunable benzimidazole show high glass‐transition temperatures (T_g's, 157–319°C) and excellent thermal stability (e.g., temperature of 5% weight loss, above 438°C in air). Dielectric constants of PAEK‐BIs measured at 25°C are all less than 2.66 in the frequency range of 0.1–50 kHz. For dense films, the ideal gas selectivity and permeability coefficients could be compared with that of commercial Ultem 1000 membrane, which indicate that the PAEK‐BIs are potential to be used for gas separation membrane material. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41289.     

Preparation of biocidal 4‐ethyl‐4‐(hydroxymethyl)oxazolidin‐2‐one‐based N‐halamine polysiloxane for impregnation of polypropylene in supercritical CO2

A cyclic N‐halamine precursor, 4‐ethyl‐4‐(hydroxymethyl)oxazolidin‐2‐one (EHMO), was synthesized and attached to poly(methylhydrosiloxane) (PMHS) through silane alcoholysis between the O? H of EHMO and Si? H of PMHS. The alcoholysis product was chlorinated with tert‐butyl hypochlorite to transfer the N? H to N? Cl and obtain an EHMO‐based N‐halamine polysiloxane. The N‐halamine polysiloxane was impregnated into inert polypropylene (PP) fibers and formed a 72 nm coating layer using supercritical carbon dioxide (scCO₂) as solvent and swelling reagent at 28 MPa and 50 °C for biocidal application. The overall synthetic procedure and the impregnation process were characterized by FTIR, XPS, and SEM, respectively. The N‐halamine polysiloxane layer on PP imparted potent antibacterial abilities against both Staphylococcus aureus and Escherichia coli while pristine ones did not exhibit noticeable killing activities. Stability tests showed that the N‐halamine polysiloxane layer was resistant to washing cycles, storage, and UV irradiation and the rechlorination of lost chlorines was good. The strategy of using CO₂‐philic PMHS as carrier polymer and scCO₂ as working solvent for impregnation presents a general and friendly procedure to functionalize inert substrates without the need of chemical linkage and organic solvent. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46624.     

Synthesis of nitropyridine‐based π‐conjugated polymers and their chemical properties

π‐Conjugated poly(3‐nitropyridine‐2,5‐diyl) ( PPy‐3‐NO₂ ), poly(3,3′‐dinitro‐2,2′‐bipyridine‐5,5′‐diyl) ( PBpy‐3,3′‐diNO₂ ), and a poly(arylene ethynylene) type polymer consisting of a 3,3′‐dinitro‐2,2′‐bipyridine unit ( PAE‐1 ) were synthesized by Cu‐promoted Ullmann coupling reaction and Pd‐catalyzed coupling reaction. PPy‐3‐NO₂ and PAE‐1 were soluble in organic solvents such as DMSO, DMF, and chloroform, and gel permeation chromatography analysis showed a number average molecular weight (M_n) of 9,300 and 12,300, respectively. PPy‐3‐NO₂ gave intrinsic viscosity, [η], of 0.53 dL g^?1 in DMF. PBpy‐3,3′‐diNO₂ had somewhat lower solubility. The polymers exhibited a UV–vis peak at about 430 nm. PPy‐NO₂ received electrochemical reduction at ?1.5 V versus Ag⁺/Ag in acetonitrile, and gave an electrochemical redox cycle in a range from 0 to ?1.1 V versus Ag⁺/Ag in an aqueous solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1763–1767, 2006     

ZIF‐11/Polybenzimidazole composite membrane with improved hydrogen separation performance

Zeolitic imidazolate framework (ZIF)‐11 crystals were prepared by the toluene‐assisted method, and they were incorporated into polysulfone, polyethersulfone, and polybenzimidazole (PBI) matrix to investigate the compatibility. ZIF‐11 had a good connection with PBI matrix as they had the same benzimidazole groups. The evaporation temperature of the membrane formation was studied with two different solvents: N‐methyl‐2‐pyrrolidone (NMP) and N,N‐dimethylacetamide (DMAc). Then, the ZIF‐11/PBI composite membranes prepared using NMP or DMAc as the solvent were characterized and tested by gas separation. Improved H₂ and CO₂ permeabilities with a H₂/CO₂ ideal selectivity of 5.6 were obtained on the 16.1 wt % ZIF‐11/PBI composite membrane prepared with DMAc as the solvent. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41056.     

Morphology and performance of poly(vinylidene fluoride) flat sheet membranes: Thermodynamic and kinetic aspects

In this study, poly(vinylidene fluoride) (PVDF) membranes were prepared using two different solvents with various polymer concentrations to investigate the predominant kinetic or thermodynamic aspects of membrane preparation in a phase separation process. For this purpose, dimethyl sulfoxide (DMSO) as a weak solvent and N‐2‐methylpyrrolidone (NMP) as a strong solvent were used with polymer concentrations between 8 and 15 wt %. Scanning electron microscopy and water content, contact angle, and pore size measurements were used to assess the factors affecting the physicochemical properties of the prepared membranes. The results showed that in the case of NMP, the membrane structure is mainly controlled by thermodynamic parameters, while when using DMSO, kinetic parameters are predominant. According to the results, the prepared PVDF‐based membranes with DMSO exhibited a relatively denser top layer and less permeation compared to the NMP/PVDF membranes. The difference between the viscosities of the casting solutions with equal polymer concentrations in DMSO and NMP was considered to be the main effective factor in solvent/nonsolvent exchange, resulting in denser top layers in the DMSO/PVDF membranes. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46419.     

Modeling flow distribution and pressure drop in redox flow batteries

The combination of interdigitated flow fields (IDFF) with porous electrodes offers lower pressure drop and better performance than conventional flow‐through porous electrodes in redox flow batteries. Comprehensive three‐dimensional and simplified one‐dimensional + two‐dimensional models describing flow uniformity and pressure losses within flow through, parallel, and interdigitated flow fields were developed and used to demonstrate the benefits of IDFF. Analytical solutions for IDFF that compare favorably with computational fluid dynamics quantify the trade between pressure loss and velocity maldistribution both along the channels and within the electrode. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3746–3755, 2018     

A super thin polytetrafluoroethylene/sulfonated poly(ether ether ketone) membrane with 91% energy efficiency and high stability for vanadium redox flow battery

In order to further decrease the cost and enhance the durability of sulfonated poly(ether ether ketone) membrane for vanadium redox flow battery, a super thin (40 μm) polytetrafluoroethylene (PTFE)/SPEEK (PS) membrane is prepared. The physico‐chemical properties and single cell performance of PS membranes prepared with different casting solvents including NMP (N‐methyl‐2‐pyrrolidone), DMF (N,N′‐dimethylformamide), and DMAc (N,N′‐dimethylacetamide) have been investigated. Results show that the energy efficiency of VRB with PS/DMF can reach up to 91.2% at the current density of 40 mA cm^?2, which is 11.1% and 6.4% higher than that of the commercial Nafion 212 and pristine SPEEK membrane, respectively. In addition, charge–discharge test over 150 times proves that the PS/DMF membrane possesses high stability and thus it is suitable for VRB application. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43593.     

Sulfonated poly(ether ether ketone)/s–TiO2 composite membrane for a vanadium redox flow battery

The SPEEK/s-TiO₂ composite membrane was prepared by blending sulfonated poly(ether ether ketone) (SPEEK) and sulfonated titanium dioxide (s-TiO₂) nanoparticles. The important physiochemical parameters such as proton conductivity, water uptake, swelling degree and ion exchange capacity of the composite membrane were measured. The thermal stability and chemical stability were also tested. It was observed that the SPEEK/s-TiO₂ composite membrane exhibited the best selectivity (7.13 × 10⁴ S·min·cm⁻³) accompanying high proton conductivity (0.061 S·cm⁻¹) and low tetravalent vanadium ion (VO²⁺) permeability (8.55 × 10⁻⁷ cm²·min⁻¹) compared with Nafion117, SPEEK and SPEEK/TiO₂ membranes. The battery performance with these membranes was characterized by charge–discharge cycling tests and it was found that the SPEEK/s-TiO₂ composite membrane showed the highest energy efficiency (EE) up to 82.3%, indicating the SPEEK/s-TiO₂ composite membrane is a candidate for vanadium redox flow battery (VRFB) application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48830.     

Second modification of a polyamide membrane surface

The aim of this study was to develop the water flux and antifouling properties of a polyamide (PA) nanofiltration membrane. A nascent PA membrane was prepared with an interfacial polymerization technique and modified with 2,5‐diaminobenzene sulfonic acid (2,5‐DABSA) as a second modification. The effects of the 2,5‐DABSA monomer concentration and the modification time on the membrane performance were investigated. The chemical structure, morphology, roughness, hydrophilicity, molecular weight cutoff, and antifouling properties of the membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force spectroscopy, contact angle measurement, poly(ethylene glycol) tracers, and cetyl trimethyl ammonium bromide filtration, respectively. The PA membrane with optimized performance was shown to have a greater than 44% higher water permeate flux with a change in the salt rejection in the order RNa₂SO₄ > RCaCl₂ > RNaCl to RNa₂SO₄ > RNaCl > RCaCl₂. The improvement of the hydrophilicity led to excellent antifouling properties in the new PA membranes and illustrated a promising and simple method for the fabrication of high‐performance PA membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43583.