Fabricating a Partially Fluorinated Hybrid Cation-Exchange Membrane for Long Durable Performance of Vanadium Redox Flow Batteries.

The long-term durability of vanadium redox flow batteries (VRFBs) depends on the stability and performance of the membrane separator. We have architected a hybrid membrane by uniform dispersion of MIL-101(Cr) (Cr-MOF) in a partially fluorinated polymer grafted with sulfonic acid groups (PHP@AMPSCr-MOF(1.0)). The single cell VRFB performance of the PHP@AMPSCr-MOF(1.0) membrane was studied in comparison with the Cr-MOF incorporated Nafion membrane (NafionCr-MOF(1.0)) and showed an excellent result with 97.5% Coulombic efficiency (CE) at 150 mA/cm2 without any significant deterioration in the charge-discharge process for 1500 cycles (over 650 h). Meanwhile, the CE value of the NafionCr-MOF membrane (94.5%) deteriorated after 800 cycles (about 360 h) under similar conditions. The high VRFB performance of the PHP@AMPSCr-MOF(1.0) membrane has been attributed to the synergized properties and good interactions between Cr-MOF and partially fluorinated polymer matrix responsible for the creation of hydrophilic proton-conducting channels to achieve high selectivity. Furthermore, the cost-effective polymer and thus membranes may open new windows for practical applications in other energy devices such as fuel cells, electrolysis, and water treatment.

Correction to Poly(vinylidene fluoride-co-chlorotrifluoro ethylene) Nanohybrid Membrane for Fuel Cell.

[This corrects the article DOI: 10.1021/acsomega.7b01635.].

Membrane distillation crystallization technology for zero liquid discharge and resource recovery: Opportunities, challenges and futuristic perspectives.

Water resources are getting limited, which emphasises the need for the reuse of wastewater. The conventional waste(water) treatment methods such as reverse osmosis (RO) and multi-effect distillation (MED) are rendered limited due to certain limitations. Moreover, the imposition of stringent environmental regulations in terms of zero liquid discharge (ZLD) of wastewater containing very high dissolved solids has assisted in developing technologies for the recovery of water and useful solids. Membrane distillation crystallization (MDCr) is an emerging hybrid technology synergising membrane distillation (MD) and crystallization, thus achieving ZLD. MDCr technology can be applied to desalinate seawater, treat nano-filtration, and RO reject brine and industrial wastewater to increase water recovery and yield useful solids. This manuscript focuses on recent advances in MDCr, emphasizing models that account for application in (waste)water treatment. MDCr has dual benefits, first the environmental conservation due to non-disposal of wastewater and second, resources recovery proving the proverb that waste is a misplaced resource. Limitations of standalone MD and crystallization are discussed to underline the evolution of MDCr. In this review, MDCr's ability and feasibility in the treatment of industrial wastewater are highlighted. This manuscript also examines the operational issues, including crystal deposition (scaling) on the membrane surface, pore wetting phenomenon and economic consequences (energy use and operating costs). Finally, opportunities and future prospects of the MDCr technology are discussed. MDCr technology can amplify natural resources availability by recovering freshwater and useful minerals from the waste stream, thus compensating for the relatively high cost of the technology.

An Investigation of a (Vinylbenzyl) Trimethylammonium and N-Vinylimidazole-Substituted Poly (Vinylidene Fluoride-Co-Hexafluoropropylene) Copolymer as an Anion-Exchange Membrane in a Lignin-Oxidising Electrolyser.

Electrolysis is seen as a promising route for the production of hydrogen from water, as part of a move to a wider "hydrogen economy". The electro-oxidation of renewable feedstocks offers an alternative anode couple to the (high-overpotential) electrochemical oxygen evolution reaction for developing low-voltage electrolysers. Meanwhile, the exploration of new membrane materials is also important in order to try and reduce the capital costs of electrolysers. In this work, we synthesise and characterise a previously unreported anion-exchange membrane consisting of a fluorinated polymer backbone grafted with imidazole and trimethylammonium units as the ion-conducting moieties. We then investigate the use of this membrane in a lignin-oxidising electrolyser. The new membrane performs comparably to a commercially-available anion-exchange membrane (Fumapem) for this purpose over short timescales (delivering current densities of 4.4 mA cm-2 for lignin oxidation at a cell potential of 1.2 V at 70 °C during linear sweep voltammetry), but membrane durability was found to be a significant issue over extended testing durations. This work therefore suggests that membranes of the sort described herein might be usefully employed for lignin electrolysis applications if their robustness can be improved.

Poly(vinylidene fluoride-co-chlorotrifluoro ethylene) Nanohybrid Membrane for Fuel Cell.

Through nanochannels are created in the polymer/hybrid films by irradiating swift heavy ions followed by selective chemical etching of the amorphous latent track caused by irradiation. The dimensions of the nanochannels are varied from 30 to 100 nm by either using small (lithium) and large (silver) size of swift heavy ions with high energy (80 MeV) or by embedding few percentage of two-dimensional nanoparticle in the polymer matrix. The side walls of the nanochannels are grafted with polystyrene using the free radicals created during irradiation. Polystyrene graft is functionalized by tagging sulfonate group in the benzene ring of polystyrene to make the nanochannels conducting and hydrophilic. The proof of grafting and functionalization is shown through various spectroscopic techniques. The relaxation behavior and thermal stability of graft polymer within the nanochannel are shown through different thermal measurements. Nanoclay in nanohybrid nucleates the piezoelectric phase in the polymer matrix whose extent is further increased in grafted and functionalized specimen. Functionalized nanochannels exclusively facilitate proton conducting, whereas the remaining part of the film is electroactive, making it as a smart membrane. Greater water uptake, ion exchange capacity (IEC), high activation energy (8.3 × 103 J mol-1), and high proton conduction (3.5 S m-1) make these functionalized nanohybrid film a superior membrane. Membrane electrode assembly has been made to check the suitability of these membranes for fuel cell application. Open circuit voltage and potential are significantly high for nanohybrid membrane (0.6 V) as compared to pure polymer (0.53 V). Direct methanol fuel cell testing using the membrane assembly exhibit a considerable high power density of ∼400 W m-2, making these developed membranes suitable for fuel cell application and providing the ability to replace standard membrane like Nafion, as the methanol permeability is low, thus raising the higher selectivity parameter of the nanohybrid membrane.

Cation-Exchange Membrane with Low Frictional Coefficient and High Limiting Current Density for Energy-Efficient Water Desalination.

A sulfonated poly(ether ether ketone) (SPEEK) and phosphorylated graphene oxide (PGO) composite of a cation-exchange membrane with low frictional coefficient and high limiting current density has been reported for water desalination by rapid electrodialysis. The incorporation of PGO in the membrane matrix showed a significant impact on the macroscopic properties, counterion frictional coefficient, and performance of the membrane. A well-optimized SPEEK/PGO-8 (8% PGO content, w/w) membrane showed improved conductivity (4.15 × 10-2 S cm-1) and permselectivity (87%), and excellent stabilities (thermal, mechanical, and chemical) because of cherished polymer-PGO (filler) interaction via H-bonding. The efficiency of the SPEEK/PGO-8 membrane was also evaluated for the desalination of brackish water near limiting current density (I lim). Ion concentration polarization (ICP) was assessed by i-V curves, and below I lim, water splitting or change in product water pH was ruled out. While above I lim (10.5 mA cm-2), ICP was significant and could be finally tuned with applied current density for producing desalinated water with a desired pH. Furthermore, improved I lim, high current efficiency (82.9%), and low energy consumption (7.9 kWh kg-1 of the salt removed) of the SPEEK/PGO-8 membrane during electrodialysis provide a broad current window for efficient and rapid water desalination/purification.

Graphene oxide based nanohybrid proton exchange membranes for fuel cell applications: An overview.

In the context of many applications, such as polymer composites, energy-related materials, sensors, 'paper'-like materials, field-effect transistors (FET), and biomedical applications, chemically modified graphene was broadly studied during the last decade, due to its excellent electrical, mechanical, and thermal properties. The presence of reactive oxygen functional groups in the grapheme oxide (GO) responsible for chemical functionalization makes it a good candidate for diversified applications. The main objectives for developing a GO based nanohybrid proton exchange membrane (PEM) include: improved self-humidification (water retention ability), reduced fuel crossover (electro-osmotic drag), improved stabilities (mechanical, thermal, and chemical), enhanced proton conductivity, and processability for the preparation of membrane-electrode assembly. Research carried on this topic may be divided into protocols for covalent grafting of functional groups on GO matrix, preparation of free-standing PEM or choice of suitable polymer matrix, covalent or hydrogen bonding between GO and polymer matrix etc. Herein, we present a brief literature survey on GO based nano-hybrid PEM for fuel cell applications. Different protocols were adopted to produce functionalized GO based materials and prepare their free-standing film or disperse these materials in various polymer matrices with suitable interactions. This review article critically discussed the suitability of these PEMs for fuel cell applications in terms of the dependency of the intrinsic properties of nanohybrid PEMs. Potential applications of these nanohybrid PEMs, and current challenges are also provided along with future guidelines for developing GO based nanohybrid PEMs as promising materials for fuel cell applications.

Phosphorylated cellulose triacetate-silica composite adsorbent for recovery of heavy metal ion.

Phosphorylated cellulose triacetate (CTA)/silica composite adsorbent was prepared by acid catalyzed sol-gel method using an inorganic precursor (3-aminopropyl triethoxysilane (APTEOS)). Reported composite adsorbent showed comparatively high adsorption capacity for Ni(II) in compare with different heavy metal ions (Cu(2+), Ni(2+), Cd(2+) and Pb(2+)). For Ni(II) adsorption, effect of time, temperature, pH, adsorbent dose and adsorbate concentration were investigated; different kinetic models were also evaluated. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were also estimated and equilibrium adsorption obeyed Langmuir and Freundlich isotherms. Developed adsorbent exhibited about 78.8% Ni(II) adsorption at pH: 6 and a suitable candidate for the removal of Ni(II) ions from wastewater. Further, about 65.5% recovery of adsorbed Ni(II) using EDTA solution was demonstrated, which suggested effective recycling of the functionalized beads would enable it to be used in the treatment of contaminated water in industry.

2-Acrylamido-2-methyl-1-propanesulfonic Acid Grafted Poly(vinylidene fluoride-co-hexafluoropropylene)-Based Acid-/Oxidative-Resistant Cation Exchange for Membrane Electrolysis.

For developing acid-/oxidative-resistant aliphatic-polymer-based cation-exchange membrane (CEM), macromolecular modification of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) was carried out by controlled chemical grafting of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). To introduce the unsaturation suitable for chemical grafting, dehydrofluorination of commercially available PVDF-co-HFP was achieved under alkaline medium. Sulfonated copolymer (SCP) was prepared by the free radical copolymerization of dehydofluorinated PVDF-co-HFP (DHPVDF-co-HFP) and AMPS in the presence of free radical initiator. Prepared SCP-based CEMs were analyzed for their morphological characteristics, ion-exchange capacity (IEC), water uptake, conductivity, and stabilities (mechanical, chemical, and thermal) in comparison with state-of-art Nafion117 membrane. High bound water content avoids the membrane dehydration, and most optimal (SCP-1.33) membrane exhibited about ∼2.5-fold high bound water content in comparison with that of Nafion117 membrane. Bunsen reaction of iodine-sulfur (I-S) was successfully performed by direct-contact-mode membrane electrolysis in a two-compartment electrolytic cell using different SCP membranes. High current efficiency (83-99%) confirmed absence of any side reaction and 328.05 kJ mol-H2(-1) energy was required for to produce 1 mol of H2 by electrolytic cell with SCP-1.33 membrane. In spite of low conductivity for reported SCP membrane in comparison with that of Nafion117 membrane, SCP-1.33 membrane was assessed as suitable candidate for electrolysis because of its low-cost nature and excellent stabilities in highly acidic environment may be due to partial fluorinated segments in the membrane structure.

Sulfonated polyimide/acid-functionalized graphene oxide composite polymer electrolyte membranes with improved proton conductivity and water-retention properties.

Sulfonated polyimide (SPI)/sulfonated propylsilane graphene oxide (SPSGO) was assessed to be a promising candidate for polymer electrolyte membranes (PEMs). Incorporation of multifunctionalized (-SO3H and -COOH) SPSGO in SPI matrix improved proton conductivity and thermal, mechanical, and chemical stabilities along with bound water content responsible for slow dehydration of the membrane matrix. The reported SPSGO/SPI composite PEM was designed to promote internal self-humidification, responsible for water-retention properties, and to promote proton conduction, due to the presence of different acidic functional groups. Strong hydrogen bonding between multifunctional groups thus led to the presence of interconnected hydrophobic graphene sheets and organic polymer chains, which provides hydrophobic-hydrophilic phase separation and suitable architecture of proton-conducting channels. In single-cell direct methanol fuel cell tests, SPI/SPSGO-8 exhibited 75.06 mW·cm(-2) maximum power density (in comparison with commercial Nafion 117 membrane, 62.40 mW·cm(-2)) under 2 M methanol fuel at 70 °C.

Polymer thin films embedded with metal nanoparticles for electrochemical biosensors applications.

Currently, polymer thin films embedded with metal nanoparticles provided the suitable microenvironment for biomolecules immobilization retaining their biological activity with desired orientation, to facilitate electron transfer between the immobilized enzymes and electrode surfaces, better conformation and high biological activity, resultant in enhanced sensing performance. This article reviews focus on various methods for brief discussion of fabrication of metal nanoparticles-polymer hybrid materials and their applications in different electrochemical biosensors. The performance of hybrid materials based electrochemical biosensor can be improved by synergic properties of the metal nanoparticles and polymer network with biomolecules interface via engineering of morphology, particle size, effective surface area, functionality, adsorption capability and electron-transfer properties. These attractive features to hybrid materials are expected to find applications in a new generation of miniaturized, smart biochip devices.

Cross-linked hybrid nanofiltration membrane with antibiofouling properties and self-assembled layered morphology.

A new siloxane monomer, 3-(3-(diethoxy(2-(5-(4-(10-ethoxy-4-hydroxy-2,2-dimethyl-11-oxa-2-ammonio-6-aza-10-silatridecan-10-yl)phenyl)-1,3,4-oxadi azol-2-ylthio)ethyl)silyl)propylamino)-2-hydroxy-N,N,N-trimethylpropan-1-aminium chloride (OA), was synthesized by reported 3-((4-(5-(2-((3-aminopropyl) diethoxysilyl)ethylthio)-1,3,4-oxadiazol-2-yl)phenyl) diethoxysilyl)propan-1-amine (APDSMO) and glycidyltrimethylammonium chloride (GDTMAC) by epoxide ring-opening reaction. OA-poly(vinyl alcohol) (PVA) hybrid antibiofouling nanofilter (NF) membranes were prepared by acid-catalyzed sol-gel followed by formal cross-linking. Membranes showed wormlike arrangement and self-assembled layered morphology with varying OA content. Hybrid NF membrane, especially OA-6, showed low surface roughness, high hydrophilic nature, low biofouling, high cross-linking density, thermal and mechanical stablility, solvent- and chlorine-tolerant nature, along with good permeability and salt rejection. Prepared OA-6 hybrid NF membrane can be used efficiently for desalting and purification of water with about 2.0 g/L salt content (groundwater in major part of India). The described method provides novel route for producing antibiofouling membranes of diversified applications.

Bifunctionalized organic-inorganic charged nanocomposite membrane for pervaporation dehydration of ethanol.

Chitosan was modified into N-p-carboxy benzyl chitosan (NCBC) by introducing an aromatic ring grafted with acidic -COOH group and highly stable and cross-linked nanostructured NCBC-silica composite membranes were prepared for pervaporation dehydration of water-ethanol mixture. These membranes were tailored to comprise three regions namely: hydrophobic region, highly charged region and selective region, in which weak acidic group (-COOH) was grafted at organic segment while strong acidic group (-SO(3)H) was grafted at inorganic segment to achieve high stability and less swelling in water-ethanol mixture. Cross-linking density and NCBC-silica content in membrane matrix has been systematically optimized to control the nanostructure of the developed polymer matrix for studying the effects of molecular structure on the swelling, and PV performance. Among prepared membranes, nanocomposite membrane with 3h cross-linking time and 90% (w/w) of NCBC-silica content (PCS-3-3) exhibited 1.66×10(-4)cm(3)(STP) cm/cm(2) s cmHg water permeability (P(W)), while 1.35×10(-7) cm(3)(STP) cm/cm(2) s cmHg ethanol permeability (P(EtOH)) of developed membrane and 1231 PV selectivity factor at 30 °C for separating water from 90% (w/w) ethanol mixture.

Cross-linked poly(vinyl alcohol)-poly(acrylonitrile-co-2-dimethylamino ethylmethacrylate) based anion-exchange membranes in aqueous media.

Hydroxide anion conducting polymer membranes also termed as anion exchange membranes (AEMs) are recently becoming important materials for electrochemical technology, alkaline fuel cells, and electrolyzers. In this work, the preparation procedure for AEMs based on poly(vinyl alcohol) (PVA) and copolymer of poly(acrylonitrile (PAN)-dimethylamino ethylmethacrylate) (DMAEMA) with strongly basic quaternary ammonium in aqueous media has been reported. This simplified procedure avoids the use of chloromethyl methyl ether (CME), a carcinogen that is harmful to human health, generally used for chloromethylation during AEM preparation. Developed AEMs were extensively characterized by studying physicochemical and electrochemical properties, to assess their suitability for electrodialytic ion separation. These membranes were designed to possess all the required properties of a highly anion conductive membrane such as reasonable water uptake, good ion-exchange capacity (1.18 mequiv g(-1)), high permselectivity (0.90), along with reasonable conductivity (3.45 mS cm(-1)) due to quaternary ammonium group functionality. The membrane conductivity values in conjunction with solution conductivity have been used for the estimation of the isoconductivity point, considering the membrane as a combination of the gel phase and integral phase. Electroosmotic studies revealed quite low mass drag and equivalent pore radius (2.7-4.0 A) of the membrane, which are also desirable properties of an AEM. The excellent electrotransport property of AEM-70 for practical anion separation was concluded from i-v studies. Electrodialytic performance of the AEM-70 membrane revealed its suitability for applications in electromembrane processes.

Crosslinked chitosan/polyvinyl alcohol blend beads for removal and recovery of Cd(II) from wastewater.

Crosslinked chitosan/poly(vinyl alcohol) (PVA) beads were prepared by suspension of chitosan-PVA aqueous solution in a mixture of toluene and chlorobenzene. Some quantity of the water was distilled out as an azeotrope along with toluene-chlorobenzene and the droplets were chemically crosslinked by adding glutaraldehyde. The prepared crosslinked beads were characterized by FTIR, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The developed beads were used as an adsorbent for the adsorption of Cd(II) from wastewater. Effect of time, temperature, pH, adsorbent dose and adsorbate concentration on the adsorption of Cd(II) were investigated in batch process and pseudo-first and pseudo-second-order kinetic models were also evaluated. The equilibrium adsorption obeyed Langmuir and Freundlich isotherms as well as the thermodynamic parameters such as DeltaG degrees , DeltaH degrees and DeltaS degrees were calculated. From thermodynamic data, it was found that the adsorption process was endothermic and spontaneous. The maximum adsorption of Cd(II) ions was found to be 73.75% at pH 6 and indicated that developed material could be effectively utilized for the removal of Cd(II) ions from wastewater.

3-[[3-(Triethoxysilyl)propyl]amino]propane-1-sulfonic acid-poly(vinyl alcohol) cross-linked zwitterionic polymer electrolyte membranes for direct methanol fuel cell applications.

Recently, organic-inorganic nanocomposite zwitterionic polymer electrolyte membranes (PEMs) have attracted remarkable interest for application to the direct methanol fuel cell (DMFC) operated at intermediate temperature (100-200 degrees C). In this paper, we report the synthesis of an organic-inorganic hybrid zwitterionomer silica precursor with ammonium and sulfonic acid functionality by the ring-opening of 3-propanesultone under mild heating conditions and the preparation procedure of a proton-conductive and stable organic-inorganic zwitterion-poly(vinyl alcohol) (PVA) cross-linked PEM by sol-gel in aqueous media. Developed PEMs were extensively characterized by studying their physicochemical and electrochemical properties under DMFC operating conditions. These membranes were designed to possess all of the required properties of a proton-conductive membrane, namely, reasonable swelling, good mechanical, dimensional, and oxidative strength, flexibility, and low methanol permeability along with reasonable proton conductivity (4.85 x 10(-2) S cm(-1)) due to zwitterionic functionality. Moreover, from the selectivity parameter among all developed membranes, ZI-70 [zwitterionomer membrane with 70 wt % of PVA of 3-[[3-(triethoxysilyl)propyl]amino]propane-1-sulfonic acid in the membrane matrix], exhibited the best results in comparison to the Nafion117 membrane for DMFC applications.

Membrane-based techniques for the separation and purification of proteins: an overview.

Membrane processes are increasingly reported for various applications in both upstream and downstream technology, such as microfiltration, ultrafiltration, emerging processes as membrane chromatography, high performance tangential flow filtration and electrophoretic membrane contactor. Membrane-based processes are playing critical role in the field of separation/purification of biotechnological products. Membranes became an integral part of biotechnology and improvements in membrane technology are now focused on high resolution of bioproduct. In bioseparation, applications of membrane technologies include protein production/purification, protein-virus separation. This manuscript provides an overview of recent developments and published literature in membrane technology, focusing on special characteristics of the membranes and membrane-based processes that are now used for the production and purification of proteins.

An improved process for separation of proteins using modified chitosan-silica cross-linked charged ultrafilter membranes under coupled driving forces: isoelectric separation of proteins.

Functionalized chitosan namely as N-methylene phosphonic chitosan (PC) and quaternized chitosan (QC) silica composite charged ultrafilter membranes were prepared by acid catalyzed sol-gel method in the aqueous media and gelated in methanol for tailoring their pore structure. These membranes were employed for developing a simple membrane process for pH sensitive protein fractionation under coupled driving forces (pressure and electric gradient). Protein transmission (selectivity) and membrane throughput across both membranes were studied using binary mixture of protein under different gradients at pH points: 2.0, 4.8, 10.7, and 13.0. It was concluded that separation from the binary mixture of BSA-LYS, separation LYS at pH 4.8 (pI of BSA) using negatively charged PC-Si membrane or separation BSA at pH 10.7 (pI of LYS) using positively charged QC-Si membrane, was possible with high selectivity. Also in all cases, due to coupling of driving forces, filtrate flux and selectivity were enhanced by several folds. Furthermore, applied electric gradient progressively increased the separation factor values, which was close to 10 for PC-Si and 15 for QC-Si membranes. Relatively high separation value of individual protein from binary mixture and filtrate velocity suggests the practical usefulness of this novel process and biopolymer membranes.

Functionalized organic-inorganic nanostructured N-p-carboxy benzyl chitosan-silica-PVA hybrid polyelectrolyte complex as proton exchange membrane for DMFC applications.

Chitosan was modified into N-p-carboxy benzyl chitosan (NCBC) by introducing an aromatic ring grafted with carboxylic acid as the proton conducting group. A preparation procedure of highly conductive and stable organic-inorganic nanostructured NCBC-silica-poly(vinyl alcohol) (PVA), proton exchange membrane (PEM) for direct methanol fuel cell (DMFC), by the sol-gel method in aqueous media has been reported. These PEMs were developed by cross-linking and designed to consist of weak proton conducting (-COOH) groups at organic segments and strong proton conducting (-SO3H) groups at inorganic segments to achieve high charge density and stabilities. Cross-linking density and NCBC-silica content in the membrane matrix were systematically optimized to control their nanostructure, thermal, mechanical, and chemical stabilities, as well as proton and fuel transport properties. Developed PEMs were extensively characterized by studying their physicochemical and electrochemical properties under DMFC operating conditions. As these PEMs were well processed as self-supporting film, they showed high stabilities and proton conductivity and low methanol permeability. Moreover, among all synthesized membranes, PCS-3-3 hybrid PEM exhibited quite a high selectivity parameter in comparison to Nafion117 membrane for DMFC applications.

Sulfonated poly(styrene-co-maleic anhydride)-poly(ethylene glycol)-silica nanocomposite polyelectrolyte membranes for fuel cell applications.

A method for the preparation of highly conductive and stable organic-inorganic nanocomposite polyelectrolyte membranes with controlled spacing between inorganic segment and covalently bound sulfonic acid functional groups has been established. These polyelectrolyte membranes were prepared by condensation polymerization of the silica precursor (tetraethylorthosilicate) in dimethylacetamide in the presence of poly(ethylene glycol) (PEG) of desired molecular weight, and sulfonated poly(styrene-co-maleic anhydride) was attached to the polymeric backbone by hydrogen bonding. Molecular weight of PEG has been systematically changed to control the nanostructure of the developed polymer matrix for studying the effects of molecular structure on the thermal as well as conductive properties. These polyelectrolyte membranes were extensively characterized by studying their thermo-gravimetric analysis (TGA), ion-exchange capacity (IEC), water content, conductivity, methanol permeability, and current-voltage polarization curves under direct methanol fuel cell (DMFC) operating conditions as a function of silica content and molecular weight of PEG used for membrane preparation. Moreover, from these studies and estimation of selectivity parameter among all synthesized membranes, 30% silica content and 400 Da molecular weight of PEG resulted in the best nanocomposite polyelectrolyte membranes, which exhibited performance comparable to that of the Nafion 117 membrane for DMFC applications.