Gadolinium‐conjugated FA‐PEG‐PAMAM‐COOH nanoparticles as potential tumor‐targeted circulation‐prolonged macromolecular MRI contrast agents

The aim of research is to develop potential tumor‐targeted circulation‐prolonged macromolecular magnetic resonance imaging (MRI) contrast agents without the use of low molecular gadolinium (Gd) ligands. The contrast agents were based on polymer–metal complex nanoparticles with controllable particle size to achieve the active and passive tumor‐targeted potential. In particular, poly (amidoamine) (PAMAM) dendrimer with 32 carboxylic groups was modified with folate‐conjugated poly (ethyleneglycol) amine (FA‐PEG‐NH₂, M_w: 2 k and 4 kDa). FA‐PEG‐PAMAM‐Gd macromolecular MRI contrast agents were prepared by the complex reaction between the carboxylic groups in PAMAM and GdCl₃. The structure of FA‐PEG‐PAMAM‐COOH was confirmed by nuclear magnetic resonance (¹H‐NMR), Fourier transform infrared (FTIR) spectra, and electrospray ionization mass spectra (ESI‐MS). The mass percentage content of Gd (III) in FA‐PEG‐PAMAM‐Gd was measured by inductively coupled plasma‐atomic emission spectrometer (ICP‐AES). The sizes of these nanoparticles were about 70 nm measured by transmission electron microscopy, suggestion of their passive targeting potential to tumor tissue. In comparison with clinically available small molecular Gadopentetate dimeglumine, FA‐PEG‐PAMAM‐Gd showed comparable cytotoxicity and higher relaxation rate, suggestion of their great potential as tumor‐targeted nanosized macromolecular MRI contrast agents due to the overexpressed FA receptor in human tumor cell surfaces. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation of CaCO3/polymer composite films via interaction of anionic starburst dendrimer with poly(ethylenimine)

Summary The CaCO₃/poly(ethylenimine) composite film was obtained in the presence of anionic poly(amidoamine) (PAMAM) dendrimer (G=3.5), whereas the formation of composite film was not observed without PAMAM dendrimer or with PAMAM dendrimer (G=1.5) judging from the results of scanning electron micrographs (SEM). The crystal phase of the CaCO₃ film formed was found to be calcite by FT-IR and XRD analysis. The adsorption of PAMAM dendrimer on poly(ethylenimine) film might cause local high concentration of calcium ion and induce a formation of the CaCO₃ film. Received: 23 October 2000/Accepted: 10 November 2000     

Comparative study of composite membranes from nano‐metal‐oxide‐incorporated polymer electrolytes for direct methanol alkaline membrane fuel cells

A series of six composite membranes was prepared with two polymer electrolytes and three inorganic fillers, namely, silica, titania, and zirconia by a solution casting method. Two polymer electrolytes, that is, anion‐exchange membranes, were prepared from polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene (PSEBS) and polysulfone by chloromethylation and quaternization. A preliminary characterization of the ionic conductivity, methanol permeability, and selectivity ratio was done for all of the prepared composite membranes to check their suitability to work in direct methanol alkaline membrane fuel cells (DMAMFCs). The DMAMFC performance was analyzed with an in‐house fabricated single cell unit with a 25‐cm² area. Maximum performance was achieved for the composite membrane quaternized PSEBS/7.5% TiO₂ and was 74.5 mW/cm² at 60°C. For the comparison purposes, a commercially available anion‐exchange membrane (Anion Membrane International‐7001) was also investigated throughout the study. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Enhanced Electrocatalysis for Methanol Oxidation on Ordered {[PdPW11O39]5–/Pt/PAMAM}n Multilayer Composites

The {[PdPW₁₁O₃₉]^5–/Pt/PAMAM}_n multilayer composites constructed from G4.0 Amino‐terminated poly (amidoamine) dendrimer (PAMAM), Pt and Keggin‐type palladium(II)‐substituted polyoxometalates anion ([PdPW₁₁O₃₉]^5–) were prepared via layer by layer electro‐depositing technique. The X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and field emission scanning electron microscope (FE‐SEM) characterization indicate that the Pt nanoparticles have been anchored on the as‐prepared nanocomposites. And the morphologies of Pt nanoparticles are influenced by deposition potential, the number of layers of {[PdPW₁₁O₃₉]^5–/Pt/PAMAM}_n multilayer nanocomposites, and the existence of PAMAM. The electrocatalytic properties and stability of {[PdPW₁₁O₃₉]^5–/Pt/PAMAM}_n multilayer nanocomposites were investigated by cyclic voltammetry. Experimental investigation results reveal that PAMAM is a good support for Pt nanoparticle growth due to its interior cavity structure and high stability. [PdPW₁₁O₃₉]^5– play an important role to prevent intermediate product (mainly as CO) in the methanol oxidation from poisoning the as‐prepared catalyst. The {[PdPW₁₁O₃₉]^5–/Pt/PAMAM}₃/GC shows better electrocatalytic properties, stability, and CO tolerance ability than Pt/GC and {Pt/PAMAM}₃/GC fabricated by similar electrodeposition processes.     

Characterization of semi‐interpenetrating polymer network polystyrene cation‐exchange membranes

Polystyrene cation exchange membranes were prepared by a PVC‐based semi‐interpenetrating polymer network (IPN) method. The reaction behaviors during polymerization and sulfonation in the preparation method were investigated. The prepared membranes were characterized in terms of the physical and electrochemical properties. The membranes exhibited reasonable mechanical properties (tensile strength, 13 MPa, and elongation at break, 52%) for an ion‐exchange membrane with the ratio of polystyrene–divinylbenzene (DVB)/poly(vinyl chloride) (PVC) (R_St‐DVB/PVC) of below 0.9. Fourier transform infrared/attenuated total reflectance, differential scanning calorimetry, and scanning electron microscopy studies revealed the formation of a homogeneous membrane. The resulting membrane showed membrane electrical resistance of 2.0 Ω cm² and ion‐exchange capacity of 3.0 meq/g dry membrane. The current–voltage (I–V) curves of the membrane show that the semi‐IPN polystyrene membranes can be properly used at a high current density, and that the distribution of cation‐exchange sites in the membrane was more homogenous than that in commercial membranes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1488–1496, 2003     

Sulfonated poly(bis‐A)‐sulfones as proton exchange membranes for direct methanol fuel cell application

Sulfonated poly(bis‐A)‐sulfone (SPSF) samples were prepared by a mild postsulfonation method using trimethylsilyl chlorosulfonate as sulfonation agent, and their thermal and mechanical properties were evaluated. The serials of SPSF membranes are thermally stable up to 450°C in air. When compared with the poly(bis‐A)‐sulfone membrane, the hydrophilicity and water uptake of the SPSF membranes are enhanced. A microphase‐separated structure comprised of hydrophilic and hydrophobic polymer backbone was observed from atomic force microscopy phase images. The hydrophilic ionic clusters become continuous to form channels when ion exchange capacity (IEC) reached 1.47 mequiv/g. Moreover, the membranes showed very good proton conductivities (20°C, 0.01–0.11 S/cm) and low‐methanol permeability (0.09–3.06 × 10^?6 cm²/s), and the methanol diffusion coefficients were lower than that of Nafion112 (1.35 × 10^?6 cm²/s) with IEC values from 0.70 to 1.47 mequiv/g. However, the Fenton's reagent test revealed that the membranes exhibited very poor oxidation stability, which is the main defect limiting the application of SPSF for proton exchange membranes. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers     

Liver‐targeting doxorubicin‐conjugated polymeric prodrug with pH‐triggered drug release profile

The aim of the research presented was to develop a potential liver‐targeting prolonged‐circulation polymeric prodrug of doxorubicin (Dox) with a pH‐triggered drug release profile. In particular, linear dendritic block copolymers composed of polyamidoamine dendrimer (PAMAM) and poly(ethylene glycol) (PEG; number‐average molecular weight of 2000 g mol^?1) with or without galactose (Gal) were synthesized. Dox was coupled to the copolymers via an acid‐labile hydrazone linker. These prodrugs, designated Gal‐PEG‐b‐PAMAM‐Dox_n and mPEG‐b‐PAMAM‐Dox_m, showed accelerated Dox release as the pH decreased from 8.0 to 5.6. Cytotoxicity of the prodrugs was lower than that of free Dox due to the gradual drug release nature. Compared to mPEG‐b‐PAMAM‐Dox_m, Gal‐PEG‐b‐PAMAM‐Dox_n showed rather high cytotoxicity against Bel‐7402, suggestive of its galactose receptor‐mediated enhanced tumor uptake. This galactose receptor‐mediated liver‐targeted profile was further confirmed by the prolonged retention time in hepatoma tissue monitored using magnetic resonance imaging. Gal‐PEG‐b‐PAMAM‐Dox_n showed better in vivo antitumor efficacy than free Dox, suggesting its great potential as a polymeric antitumor prodrug. Copyright © 2010 Society of Chemical Industry     

Electrospun poly(lithium 2‐acrylamido‐2‐methylpropanesulfonic acid) fiber‐based polymer electrolytes for lithium‐ion batteries

Novel single‐ion conducting polymer electrolytes based on electrospun poly(lithium 2‐acrylamido‐2‐methylpropanesulfonic acid) (PAMPSLi) membranes were prepared for lithium‐ion batteries. The preparation started with the synthesis of polymeric lithium salt PAMPSLi by free‐radical polymerization of 2‐acrylamido‐2‐methylpropanesulfonic acid, followed by ion‐exchange of H⁺ with Li⁺. Then, the electrospun PAMPSLi membranes were prepared by electrospinning technology, and the resultant PAMPSLi fiber‐based polymer electrolytes were fabricated by immersing the electrospun membranes into a plasticizer composed of ethylene carbonate and dimethyl carbonate. PAMPSLi exhibited high thermal stability and its decomposition did not occur until 304°C. The specific surface area of the electrospun PAMPSLi membranes was raised from 9.9 m²/g to 19.5 m²/g by varying the solvent composition of polymer solutions. The ionic conductivity of the resultant PAMPSLi fiber‐based polymer electrolytes at 20°C increased from 0.815 × 10^?5 S/cm to 2.12 × 10^?5 S/cm with the increase of the specific surface area. The polymer electrolytes exhibited good dimensional stability and electrochemical stability up to 4.4 V vs. Li⁺/Li. These results show that the PAMPSLi fiber‐based polymer electrolytes are promising materials for lithium‐ion batteries. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Free‐standing hybrid anion‐exchange membranes for application in fuel cells

A series of free‐standing hybrid anion‐exchange membranes were prepared by blending brominated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (BPPO) with poly(vinylbenzyl chloride‐co‐γ‐methacryloxypropyl trimethoxy silane) (poly(VBC‐co‐γ‐MPS)). Apart from a good compatibility between organic and inorganic phases, the hybrid membranes had a water uptake of 32.4–51.8%, tensile strength around 30 MPa, and T_d temperature at 5% weight loss around 243–261°C. As compared with the membrane prepared from poly (VBC‐co‐γ‐MPS), the hybrid membranes exhibited much better flexibility, and larger ion‐exchange capacity (2.19–2.27 mmol g^?1) and hydroxyl (OH^?) conductivity (0.0067–0.012 S cm^?1). In particular, the hybrid membranes with 60–75 wt % BPPO had the optimum water uptake, miscibility between components, and OH^? conductivity, and were promising for application in fuel cells. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of stearyl‐group‐terminated dendrimers and thermosensitivity of their toluene solutions

Stearyl‐group‐terminated poly(ester amide) dendrimers [PEAD (R)₃ and PEAD (R)₈] and a poly(amino amide) dendrimer [PAMAM (R)₄] were synthesized by the amidation of three, eight, and four terminated primary amino groups in poly(ester amine) dendrimers and a poly(amino amide) dendrimer with stearyl chloride. The dendrimer structures were characterized with IR and elemental analysis. The toluene solutions of the stearyl‐group‐terminated dendrimers were thermosensitive. Not only did gels form in PEAD (R)₃–, PEAD (R)₈–, and PAMAM (R)₄–toluene solutions below 57.5, 60, and 49°C, respectively, but the content of toluene in the gels depended on the temperature, and a break existed at about 30°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 341–346, 2005     

Transport Properties of Ion‐Exchange Membranes During Pervaporation of Water‐Alcohol Mixtures

Abstract

Pervaporation properties of PESS ion‐exchange membranes in contact with water‐aliphatic alcohol mixtures were obtained. PESS ion‐exchange membranes were prepared by chemical modification of the interpenetrating polymer network system polyethylene‐poly(styrene‐co‐divinylbenzene). PESS membranes were loaded with different alkali metal ions as counterions. The obtained data showed that properties of PESS membranes depended strongly on the kind of counterions, degree of crosslinking, and difference in the polarities between water and organic component of the binary mixture. Results obtained for PESS membranes were compared with data obtained for Nafion 117 ion‐exchange membrane.     

Lithium ion transport through nonaqueous perfluoroionomeric membranes

The transport properties of lithiated perfluorinated ionomers imbibed with nonaqueous solvents and solvent mixtures were studied. Polymeric ion‐exchange membranes have potential use in the next generation single‐ion secondary lithium polymer batteries, where the lithiated form of the membrane is used as a polymer electrolyte. The novelty of the approach for lithium battery applications lies in the advantage offered by a transference number of unity, no additional salt (e.g., LiPF₆) is needed, and the excellent physical and chemical stability of the fluoropolymers. Ion‐exchange membranes were converted to the Li⁺ salt form and analyzed for total conversion using FT‐IR. Nonaqueous solvents and solvent mixtures were imbibed into the membranes in a glove box, and the uptake was measured over time. A four‐point probe was used to determine the ionic conductivity based on impedance measurements performed over a frequency range of 10 to 35,000 Hz. Conductivities exceeding 10^?4 S/cm with transference numbers of unity were achieved making these ionomeric membranes potentially useful in rechargeable lithium polymer batteries.     

Preparation and characterization of monovalent ion‐selective poly(vinyl chloride)‐blend‐poly(styrene‐co‐butadiene) heterogeneous anion‐exchange membranes

New types of composite anion‐exchange membranes were prepared by blending of suspension‐produced poly(vinyl chloride) (S‐PVC) and poly(styrene‐co‐butadiene), otherwise known as styrene–butadiene rubber (SBR), as binder, along with anion‐exchange resin powder to provide functional groups and activated carbon as inorganic filler additive. Also, an ultrasonic method was used to obtain better homogeneity. In solutions with mono‐ and divalent anions, the effect of activated carbon and sonication on the morphology, electrochemical properties and selectivity of these membranes was elucidated. For all solutions, ion‐exchange capacity, membrane potential, permselectivity, transport number, ionic permeability, flux and current efficiency of the prepared membranes initially increased on increasing the activated carbon concentration to 2 wt% in the casting solution and then began to decrease. Moreover, the electrical resistance and energy consumption of the membranes initially decreased on increasing the activated carbon loading to 2 wt% and then increased. S‐PVC‐blend‐SBR membranes with additive showed a decrease in water content and a slight decrease in oxidative stability. Also, these membranes showed good monovalent ion selectivity. Structural images of the prepared membranes obtained using scanning optical microscopy showed that sonication increased polymer‐particle interactions and promoted the compatibility of particles with binder. Copyright © 2010 Society of Chemical Industry     

Novel membranes based on poly(5‐(methacrylamido)tetrazole) and sulfonated polysulfone for proton exchange membrane fuel cells

Proton‐exchange membrane fuel cells (PEMFC)s are increasingly regarded as promising environmentally benign power sources. Heterocyclic molecules are commonly used in the proton conducting membranes as dopant or polymer side group due to their high proton transfer ability. In this study, 5‐(methacrylamido)tetrazole monomer, prepared by the reaction of methacryloyl chloride with 5‐aminotetrazole, was polymerized via conventional free radical mechanism to achieve poly(5‐(methacrylamido)tetrazole) homopolymer. Novel composite membranes, SPSU‐PMTetX, were successfully produced by incorporating sulfonated polysulfone (SPSU) into poly(5‐(methacrylamido)tetrazole) (PMTet). The sulfonation of polysulfone was performed with trimethylsilyl chlorosulfonate and high degree of sulfonation (140%) was obtained. The homopolymers and composite membranes have been characterized by NMR, FTIR, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). ¹H‐NMR and FTIR confirmed the sulfonation of PSU and the ionic interaction between sulfonic acid and poly(5‐(methacrylamido)tetrazole) units. TGA showed that the polymer electrolyte membranes are thermally stable up to ～190°C. Scanning electron microscopy analysis indicated the homogeneity of the membranes. This result was also supported by the appearance of a single T_g in the DSC curves of the blends. Water uptake and proton conductivity measurements were, as well, carried out. Methanol permeability measurements showed that the composite membranes have similar methanol permeability values with Nafion 112. The maximum proton conductivity of anhydrous SPSU‐PMTet0.5 at 150°C was determined as 2.2 × 10^?6 S cm^?1 while in humidified conditions at 20°C a value of 6 × 10^?3 S cm^?1 was found for SPSU‐PMTet2. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40107.     

Gelation and swelling behavior of end-linked hydrogels prepared from linear poly(ethylene glycol) and poly(amidoamine) dendrimers

Linear α,ω di-epoxide-terminated poly(ethylene glycol) of molar mass 4000 g mol⁻¹ was end-linked with amine-terminated poly(amidoamine) (PAMAM) dendrimers of generations 0, 2, and 4 in water to prepare architecturally well-defined copolymer hydrogels. The gelation and equilibrium swelling of the gels in water were characterized while systematically varying the polymer concentration at preparation, dendrimer generation, and mole ratio of dendrimer endgroups to PEG endgroups. The Ahmad-Rolfes-Stepto (ARS) theory of non-linear polymerization was applied to predict conditions favoring gelation, and to estimate the extent of reaction of amine and epoxide groups. Hydrogels having a large stoichiometric excess of amines over epoxides exhibited “superabsorbent” behavior upon extraction and equilibrium swelling in pure water. The mole ratio of amines to epoxides (equivalently, the mass fraction of dendrimers) was the most important factor governing superabsorbent behavior, although the polymer volume fraction at crosslinking and dendrimer generation also affected swelling to a lesser extent. The superabsorbency arises in part from protonation of the dendrimer amine endgroups at external pH = 7, which is supported by the drastic shrinkage of the most highly swelling gels in aqueous NH₄OH at pH = 11. Equilibrium swelling at pH = 7 was noticeably enhanced in gels having a high soluble fraction and high mass fraction of dendrimers. End-linking of linear polymer precursors to PAMAM dendrimers can potentially produce novel copolymer gels that combine attractive properties of the linear precursors with high swelling and pH-responsive behavior of PAMAM-containing networks.     

Composite Membrane of Sulfonated Poly (phenylene oxide) Doped with Phosphosilicate Gels for Direct Methanol Fuel Cell

Summary The newly developed composite membranes of sulfonated poly (phenylene oxide) (SPPO) doped with phosphosilicate gel were prepared for direct methanol fuel cell (DMFC). SPPO with higher ion exchange capacity (IEC) value (IEC=2.83 mequiv./g) was chosen as polymer matrix, and the phosphosilicate gel with P/Si equal to 1.5 was employed as dopant. Sulfonation of PPO was confirmed by FT-IR and ¹H NMR. And the morphology characterization of sol particles with different stirring time was done by TEM. Moreover, the surface morphology of composite membranes was characterized by SEM. As for methanol permeability (P_M) and proton conductivity (σ), it was demonstrated that all composite membranes were displaying lower methanol permeability than Nafion^?112 and comparable conductivity to Nafion^?112 at room temperature under hydration state. When it comes to selectivity parameter (Φ=σ/P_M), composite membranes show higher Φ values than Nafion^?112, and the highest value is 4.70, 5.6 times higher than 0.845 of Nafion^?112. It is implied that the composite membranes will be the promising membrane material used in DMFC.     

Fluorenyl‐containing Quaternary Ammonium Poly(arylene ether sulfone)s for Anion Exchange Membrane Applications

A series of anion exchange membranes (AEM) based on block quaternary ammonium poly(arylene ether sulfone) (QA‐bPAES) were successfully synthesized from 9,9′‐bis(4‐hydroxyphenyl) fluorene, 4,4′‐(hexafluoroisopropylidene) diphenol and 4,4′‐difluorodiphenyl sulfone via block polymerization, chloromethylation, quaternization, alkalization and solution casting. Properties of the obtained QA‐bPAES membranes, including ion exchange capacity (IEC), water uptake, swelling ratios, methanol permeability and ion conductivity were investigated. The obtained QA‐bPAES membranes showed low water uptakes, high ion conductivities and good physical and chemical stability. For example, the membrane of QA‐bPAES(20/10)‐1.34 with IEC of 1.34 mmol g⁻¹ exhibited swelling ratios of 5.0% and 5.1% in in‐plane and through‐plane direction, respectively, and ion conductivity of 15.6 mS cm⁻¹ in water at 60 °C with low methanol permeability of 1.06 × 10⁻⁷ cm² s⁻¹ (25 °C). All the results indicated that this type of block membranes had good potentials for alkaline anion exchange membrane fuel cell applications.     

Proton exchange composite membranes from blends of brominated and sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide)

New composite proton exchange membrane was prepared by mixing a 1‐methyl‐2‐pyrrolidone (NMP) solution of sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPO) in sodium form and brominated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (BPPO) for hydrophilic‐hydrophobic balance, then casting the solution as a thin film, evaporating the solvent, and treating the membrane with aqueous hydrochloric acid. The resulting membranes were subsequently characterized using FTIR‐ATR, SEM‐EDXA, and TGA instrumentation as well as measurements of basic properties such as ion exchange capacity (IEC), water uptake, proton conductivity, methanol permeability, and single cell performance. Water uptake, IEC, proton conductivity, and methanol permeability all increased with a corresponding increase of SPPO content. By properly compromising the conductivity and methanol permeability, membranes with 60–80 wt % SPPO content exhibited comparable proton conductivity to that of Nafion^® 117, with only half the methanol permeability, thereby demonstrating higher single cell performance. The membranes developed in this study could thus be a suitable candidate electrolyte for proton exchange membrane fuel cells (PEMFCs). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of homogeneously sulfonated poly(ether ether ketone) membranes: Effect of casting solvent

Poly(ether ether ketone) (PEEK) was homogeneously sulfonated to have various degrees of sulfonation from 48 to 83%. The sulfonated PEEK (sPEEK) membranes were prepared by a solvent casting method using a few solvents such as N,N‐dimethyl formamide, N,N‐dimethyl acetamide, and 1‐methyl‐2‐pyrrolidinone. The effect of casting solvent on the membrane morphology and properties was investigated. The sulfonation degree and ion exchange capacity were determined by a back titration method, and the morphology of membrane by SEM. It has been demonstrated that the surface morphology and properties of sPEEK membranes, such as water uptake, methanol permeability, ion conductivity, and mechanical strength, were considerably affected by the type of solvent, where the DMAC‐sPEEK system showed the best performance in the polymer electrolyte membrane application for DMFC. This solvent effect on the membrane morphology and properties was caused by interaction strength (hydrogen bonding) between polymer and solvent. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Highly selective sulfonated poly(vinylidene fluoride‐co‐hexafluoropropylene)/poly(ether sulfone) blend proton exchange membranes for direct methanol fuel cells

Proton exchange membranes (PEMs) based on blends of poly(ether sulfone) (PES) and sulfonated poly(vinylidene fluoride‐co‐hexafluoropropylene) (sPVdF‐co‐HFP) were prepared successfully. Fabricated blend membranes showed favorable PEM characteristics such as reduced methanol permeability, high selectivity, and improved mechanical integrity. Additionally, these membranes afford comparable proton conductivity, good oxidative stability, moderate ion exchange capacity, and reasonable water uptake. To appraise PEM performance, blend membranes were characterized using techniques such as Fourier transform infrared spectroscopy, AC impedance spectroscopy; atomic force microscopy, and thermogravimetry. Addition of hydrophobic PES confines the swelling of the PEM and increases the ultimate tensile strength of the membrane. Proton conductivities of the blend membranes are about 10^?3 S cm^?1. Methanol permeability of 1.22 × 10^?7cm² s^?1 exhibited by the sPVdF‐co‐HFP/PES10 blend membrane is much lower than that of Nafion‐117. AFM studies divulged that the sPVdF‐co‐HFP/PES blend membranes have nodule like structure, which confirms the presence of hydrophilic domain. The observed results demonstrated that the sPVdF‐co‐HFP/PES blend membranes have promise for possible usage as a PEM in direct methanol fuel cells. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43907.