Partially sulfonated poly(vinylidene fluoride) (SPVdF) has been prepared by incorporation of sulfonic acid groups within poly(vinylidene fluoride), using chlorosulfonic acid as the sulfonating agent. The degree of sulfonation (DS) has been varied by modulating the duration of the sulfonation reaction. Blending of SPVdF (having DS = 36.78%) with Nafion at a constituent wt.% ratio of SPVdF:Nafion = 70:30 has resulted in the fabrication of polymer electrolyte membrane with superior properties compared to pristine Nafion-117 membrane. This particular blend composition exhibited a proton conductivity value of 3.6 × 10-2 S cm-1 (i.e. ∼12.5% increase over Nafion-117), a methanol permeability value of 6.81 × 10-7 cm2 s-1 at 6M methanol concentration (i.e. ∼99.31% decrease from Nafion-117) and a corresponding membrane selectivity value of 5.29 × 104 Ss cm-3 (i.e. an increase of approximately two-orders of magnitude over Nafion-117) at 20 °C. In addition, this blend composition has also exhibited (a) better heat stability at temperatures as high as 160 °C by virtue of it possessing higher glass transition temperature, (b) higher storage modulus, (c) higher stress relaxation at high angular frequency and (d) superior DMFC performance at high methanol feed concentration in presence of humidified, as well as, non-humidified air as the catholyte, compared to Nafion-117 membrane. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

S DAS

K DUTTA

S HAZRA

P P KUNDU

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Fuel Cells

The quest for an efficient catalyst support material for improved deposition of electrocatalyst nanaoparticles towards application in methanol oxidation reaction has been an active field of research for last few decades. The use of highly expensive, although efficient, platinum-ruthenium (Pt-Ru) catalyst demands its minimum loading requirement and maximum utilization. We, herein, propose the potentiality of polyaniline (PAni) nanostructures-based catalyst support materials towards this utilization aspect. It was realized that the PAni nanowhiskers (NWs) support exhibited better dispersion and higher utilization of the deposited Pt-Ru nanoparticles, as compared to the PAni nanofibers (NFs) and the commercial Vulcan carbon (C) supports. This led to the exhibition of higher electrocatalytic activity, suppressed catalyst poisoning and better stability by the Pt-Ru/PAni NWs catalyst system. The charge transfer rates of the catalyst systems were found to be in the order Pt-Ru/PAni NWs > Pt-Ru/PAni NFs > Pt-Ru/C. Moreover, the Pt-Ru/PAni NWs catalyst system demonstrated the lowest solution resistance and the best performance in a direct methanol fuel cell (DMFC). © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Nanostructured Polyaniline: An Efficient Support Matrix for Platinum-Ruthenium Anode Catalyst in Direct Methanol Fuel Cell

Bimetallic Ni-Ag alloy nanostructures with different ratios of Ni and Ag, prepared through a simple co-reduction process from the respective precursor metal salts, were employed as the electrocatalysts toward methanol oxidation reaction in acidic electrolyte. The previously reported superior catalytic performance exhibited by deposited Ni catalyst on sulfonated polypyrrole (SPPy) matrix is encouraging enough to further utilize SPPy as a support matrix and Ni as a primary metal catalyst. In this work, the activity of the synthesized Ni based catalyst was strongly dependent on the composition of the Ni-Ag/SPPy catalyst systems. The best performance was obtained upon utilizing a Ni:Ag ratio of 80:20. For example, this Ni-Ag (80:20)/SPPy catalyst system exhibited a higher area specific current density, a stable current density, a higher IF/IB ratio and a better single cell DMFC performance in acidic electrolyte, than that of the other prepared catalyst systems, and also, the state-of-the-art Pt-Ru on C. © 2016 IEEE.

International Conference on 21st Century Energy Needs - Materials, Systems and Applications, ICTFCEN 2016

Electrocatalytic potential of sulfonated polypyrrole-supported Ni-Ag towards methanol oxidation in acidic medium

Severe crisis of energy that our planet is going to face in the near future demands rapid development of alternative energy harnessing and storing devices. Various alternative energy devices have been developed so far, including solar cells, batteries and fuel cells, in order to compete and replace the traditionally used fossil fuel based energy technologies. A very recent addition to the list of such devices is the unitized regenerative fuel cell (URFC), which can function as a dual, i.e., electrolyzer-cum-fuel cell, device. In remote areas, where utilization of conventionally used energy sources results in high expense, URFC can serve as the best energy option, due to its relatively low cost, high efficiency and light weight. URFC utilizes bifunctional electrodes, which function in a dual mode of water electrolysis and fuel cell. The prime focus of URFC research has been to develop various low cost and highly efficient catalysts and catalyst supports towards the fabrication of alternative bifunctional electrodes and to fabricate strong and efficient bipolar plates. The aim of this review is to highlight the main outcomes of these aspects of research on URFCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Unitized Regenerative Fuel Cells: A Review on Developed Catalyst Systems and Bipolar Plates

Poly(vinylidene fluoride) (PVdF) and polyaniline (PAni) were partially sulfonated, using chlorosulfonic acid (CSA) as the sulfonating agent. The prepared partially sulfonated PVdF (SPVdF), having a degree of sulfonation ~22%, and the partially sulfonated PAni (SPAni), having a degree of sulfonation ~29%, were blended at constituent wt% ratios of SPVdF:SPAni = 95:5, 90:10, 85:15 and 80:20 in order to fabricate different blend membranes. These blend membranes exhibited extremely low methanol uptake and methanol permeability, as well as, high membrane selectivity ratios (especially at high methanol concentrations) The blend membranes also exhibited superior water uptake capacity, water swellability, ion-exchange capacity and proton conductivity, compared to the pristine PVdF and SPVdF membranes. The SPVdF:SPAni (80:20) blend membrane was found to produce the best results in terms of exhibiting the lowest methanol permeability values of 1.50×10-9 cm2s-1 (at 2 M methanol) and 6.30×10-9 cm2s-1 (at 8 M methanol), and the highest membrane selectivity values of 3.27×106 Sscm-3 (at 2 M methanol) and 7.78×105 Sscm-3 (at 8 M methanol). On the other hand, introduction of Nafion within the SPVdF/SPAni blend membrane, to form a ternary blend membrane (i.e. SPVdF:Nafion:SPAni = 50:30:20), resulted in much improved ion-exchange capacity and proton conductivity.

Fulltext

Polymer Journal

Effect of the presence of partially sulfonated polyaniline on the proton and methanol transport behavior of partially sulfonated PVdF membrane

Partially sulfonated poly(vinylidene fluoride-co-hexafluoro propylene)/partially sulfonated polyaniline (SPVdF-co-HFP/SPAni) binary blend membranes have shown promising results in terms of low methanol permeability and high membrane selectivity compared to Nafion-117 membrane. However, the proton conductivity and IEC of this binary blend membrane was much lower than Nafion-117. It was found that incorporation of minimal quantity of Nafion within SPVdF-co-HFP/SPAni blend membrane at a constituent weight % ratio of SPVdF-co-HFP:SPAni:Nafion = 50:40:10 induced significant improvements in ion-exchange capacity (IEC), proton conductivity and tensile strength over that of the binary blend membrane. In addition, the SPVdF-co-HFP/SPAni/Nafion ternary blend membrane exhibited much lower methanol permeability, higher membrane and relative selectivities and comparable IEC to Nafion-117. In effect, presence of minimal quantity of Nafion induced significant positive attributes to the ternary blend membrane; and assisted in reaching a balance between material cost and properties. © 2015 Wiley Periodicals, Inc.

Journal of Applied Polymer Science

Highly methanol resistant and selective ternary blend membrane composed of sulfonated PVdF-co-HFP, sulfonated polyaniline and nafion

Search for suitable materials for fabricating polymer electrolyte membranes (PEMs) for application in polymer electrolyte membrane fuel cells, and particularly in direct methanol fuel cells (DMFCs), has been an important field of research for the last several decades. Notable candidates that have emerged from this extensive and seemingly exhaustive research are Nafion®, poly(vinylidenefluoride), sulfonated poly(etheretherketone), poly(benzimidazole), Dow XUS®, Flemion® R, 3P-energy, Aciplex-S®, Gore-Tex®, Gore-Select®, and their different blends, copolymers and interpenetrating networks with compounds, such as poly(hexafluoropropylene), poly(acrylonitrile), poly(styrenesulfonate), and poly(methylmethacrylate). Nevertheless, the objective of achieving a much reduced methanol crossover, while maintaining a substantial level of proton conductivity, has remained by and large elusive. However, a ray of hope has been provided by conducting polymers (CPs), and this has led to a considerable number of researchers to plunge into the exploitation of this possibility. This review focuses on the application of CPs, mainly polyaniline and polypyrrole, as PEM constituents. Detailed comparisons between their functioning, and their respective utility in terms of achieving this objective have been provided. We have also discussed the following critical points: first, the effect of CPs on methanol crossover, proton conductivity, and gas diffusion, and second, thermal stability of CPs in the temperature range within which DMFC operates. © 2014 Taylor and Francis Group, LLC.

Polymer Reviews

Utilization of conducting polymers in fabricating polymer electrolyte membranes for application in direct methanol fuel cells

SUMMARY: Direct methanol fuel cells (DMFCs) have evolved over the years as a potential candidate for application as a power source in portable electronic devices and in transportation sectors. They have certain associated advantages, including high energy and power densities, ease of fuel storage and handling, ability to be fabricated with small size, minimum emission of pollutants, low cost, ready availability of fuel and solubility of fuel in aqueous electrolytes. However, in spite of several years of active research involved in the development of DMFC technology, their chemical-to-electrical energy conversion efficiencies are still lower compared with other alternative power sources traditionally used. This review paper will focus on the existing issues associated with DMFC technology and will also suggest on the possible developmental necessities required for this technology to realize its practical potentials. © 2014 John Wiley & Sons, Ltd.

International Journal of Energy Research

An overview of unsolved deficiencies of direct methanol fuel cell technology: Factors and parameters affecting its widespread use

Blend membranes fabricated from partially sulfonated poly(vinylidene fluoride-. co-hexafluoro propylene) and partially sulfonated polyaniline (SPVdF-. co-HFP/SPAni) have shown inspiring results in terms of methanol permeability, membrane selectivity and ion-exchange capacity toward their targeted application as a low cost polymeric membrane in direct methanol fuel cell. It is widely known that compared to conventional blending, layered membrane coating results in superior membrane properties. Therefore, in this work, we demonstrate fabrication of tri-layered sandwich PAni/PVdF-. co-HFP/PAni, PAni/SPVdF-. co-HFP/PAni and SPAni/SPVdF-. co-HFP/SPAni membranes and the resulting enhancements of transport properties of these coated membranes in comparison to that of pristine PVdF-. co-HFP, pristine SPVdF-. co-HFP, pristine Nafion, PVdF-. co-HFP/PAni blend, SPVdF-. co-HFP/PAni blend and SPVdF-. co-HFP/SPAni blend membranes. The tri-layered coated sandwich membranes exhibited higher proton conductivities, ion-exchange capacities, membrane selectivities and open-circuit potentials, and lower methanol permeabilities at all methanol concentrations, compared to their blend counterparts. In addition, the coated membranes exhibited superiority over pristine Nafion in terms of methanol permeability and membrane selectivity at high methanol concentrations. Furthermore, the DMFC performance obtained with the SPAni/SPVdF-. co-HFP/SPAni tri-layered coated membrane was found to be superior to that of pristine Nafion, pristine SPVdF-. co-HFP and SPVdF-. co-HFP/SPAni blend membranes at high methanol feed concentration (i.e. 6. M). © 2014 Elsevier B.V.

Journal of Membrane Science

Low methanol permeable and highly selective membranes composed of pure and/or partially sulfonated PVdF-co-HFP and polyaniline

Poly(vinylidene fluoride-co-hexafluoro propylene) is a prospective material for the fabrication of polymer electrolyte membranes (PEMs) for direct methanol fuel cells, primarily due to its low methanol permeability, high mechanical integrity and significantly low cost compared to conventionally used Nafion. However, low proton conductivity has hindered its independent use; therefore, most studies on this prospective copolymer have been done by using it in conjunction with Nafion. Nevertheless, partial sulfonation of this copolymer has resulted in increased proton conductivity while maintaining its low methanol permeability. Therefore, it seems appropriate that blending this sulfonated copolymer with a second low-cost component, which can complement its low conductive nature, can result in PEMs with high selectivity. Use of partially sulfonated polyaniline, as the second component, produced selectivity ratio of 5.85×105Sscm-3, ion-exchange capacity of 0.71meqg-1, and current density of 90.5mAcm-2 at +0.2V and 60°C and corresponding maximum power density of 18.5mWcm-2. © 2013 Elsevier Ltd.

Applied Energy

Polymer electrolyte membrane with high selectivity ratio for direct methanol fuel cells: A preliminary study based on blends of partially sulfonated polymers polyaniline and PVdF-co-HFP

Journal	Data powered by TypesetFuel Cells
Publisher	Data powered by TypesetJohn Wiley and Sons Ltd
ISSN	1615-6846