Synthesis of Sulfonated Polysulfone-block-PVDF Copolymers:  Enhancement of Proton Conductivity in Low Ion Exchange Capacity Membranes

2004 ◽  
Vol 37 (5) ◽  
pp. 1678-1681 ◽  
Author(s):  
Yunsong Yang ◽  
Zhiqing Shi ◽  
Steven Holdcroft
2006 ◽  
Vol 4 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Tetsuya Yamaki ◽  
Junichi Tsukada ◽  
Masaharu Asano ◽  
Ryoichi Katakai ◽  
Masaru Yoshida

We prepared novel ion exchange membranes for possible use in polymer electrolyte fuel cells (PEFCs) by the radiation-induced graft copolymerization of styrene and new crosslinker bis(vinyl phenyl)ethane (BVPE) into crosslinked polytetrafluoroethylene (cPTFE) films and subsequent sulfonation and then investigated their water uptake, proton conductivity, and stability in an oxidizing environment. In contrast to the conventional crosslinker, divinylbenzene (DVB), the degree of grafting of styrene∕BVPE increased in spite of high crosslinker concentrations in the reacting solution (up to 70mol%). Quantitative sulfonation of the aromatic rings in the crosslinked graft chains resulted in the preparation of membranes with a high ion exchange capacity that reached 2.9meq∕g. The bulk properties of the membranes were found to exceed those of Nafion membranes except for chemical stability. The emphasis was on the fact that the BVPE-crosslinked membranes exhibited the higher stability in the H2O2 solution at 60°C compared to the noncrosslinked and DVB-crosslinked ones, as well as decreased water uptake and reasonable proton conductivity. These results are rationalized by considering the reactivity between styrene and the crosslinker, which is an important factor determining the distribution of the crosslinks in the graft component. In the case of BVPE, the crosslinks at a high density were homogeneously incorporated even into the interior of the membrane because of its compatibility with styrene while the far too reactive DVB led to a crosslink formation only near the surface. The combination of both the cPTFE main chain and BVPE-based grafts, i.e., a perfect “double” crosslinking structure, is likely to effectively improve the membrane performances for PEFC applications.


2014 ◽  
Vol 13 (1) ◽  
pp. 7
Author(s):  
Bambang Piluharto ◽  
Imam Syafi’i ◽  
R. Indahsari ◽  
Tanti Haryati

Sulfonated polysulfone membrane is one of the alternative membranes as replacing Nafion membrane for the fuel cell application. This membrane was prepared by introducing sulfonic group in the polysulfone structure backbone, so that provides the ionic membrane. However, more ionic groups in the SPSF membrane lead to loss mechanical stability. This study aims to prepare the hybrid membrane from SPSF and bentonite. In here, various of bentonite concentrations were used as variable to study water uptake and ion-exchange capacity properties. As the results, increasing bentonite concentrations lead to increase water uptake and ion-exchange capacity. By the functional group analysis, proved that adding bentonite in SPSF did not change structure of SPSF, means that interaction between SPSF and bentonite were physical interactions.


2018 ◽  
Vol 18 (2) ◽  
pp. 313 ◽  
Author(s):  
Muhammad Ridwan Septiawan ◽  
Dian Permana ◽  
Sitti Hadijah Sabarwati ◽  
La Ode Ahmad ◽  
La Ode Ahmad Nur Ramadhan

Chitosan was modified by maleic anhydride, and it was then functionalized using heterogeneous and blending method to obtain the membrane. The results of the reaction between chitosan with maleic anhydride were signed by the new peak appears around 1475 cm-1 which attributed to C=C bending of alkene. The new peak also appears at 1590 cm-1 which attributed to N-H bending of amide. Chitosan-maleic anhydride membranes show microstructure of chitosan membrane with high porous density and rigidity while chitosan-maleic anhydride membranes have clusters. In addition, the thermal tenacity of membranes reached 500 °C. Modified membrane by heterogeneous and blending method have higher water uptake, ion exchange capacity, and proton conductivity than chitosan membrane. Moreover, the blending method is much more effective than the heterogeneous method that can be exhibited from ion exchange capacity and proton conductivity values of 1.08–6.38 meq g-1 and 1x10-3–1x10-2 S cm-1, 0.92–2.27 meq g-1 and 1.53x10-4–3.04x10-3 S cm-1, respectively. The results imply that modification of chitosan membrane with the addition of maleic anhydride using heterogeneous and blending method can be applied to proton exchange membrane.


Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 395
Author(s):  
Jonathan Teik Ean Goh ◽  
Ainul Rasyidah Abdul Rahim ◽  
Mohd Shahbudin Masdar ◽  
Loh Kee Shyuan

The polymer electrolyte membrane (PEM) is a key component in the PEM fuel cell (PEMFC) system. This study highlights the latest development of PEM technology by combining Nafion® and ionic liquids, namely 2–Hydroxyethylammonium Formate (2–HEAF) and Propylammonium Nitrate (PAN). Test membranes were prepared using the casting technique. The impact of functional groups in grafting, morphology, thermal stability, ion exchange capacity, water absorption, swelling and proton conductivity for the prepared membranes is discussed. Both hybrid membranes showed higher values in ion exchange capacity, water uptake and swelling rate as compared to the recast pure Nafion® membrane. The results also show that the proton conductivity of Nafion®/2–HEAF and Nafion®/PAN membranes increased with increasing ionic liquid concentrations. The maximum values of proton conductivity for Nafion®/2–HEAF and Nafion®/PAN membranes were 2.87 and 4.55 mScm−1, respectively, equivalent to 2.2 and 3.5 times that of the pure recast Nafion® membrane.


In this study the cation exchange membranes(CEM) were fabricated using 3 different compositions of sulphonated poly vinyl alcohol (SPVA) and phosphorylated graphene oxide(PGO) in weight ratios by physicalmixing and casting method. Loading of PGO in the SPVA improvedwater uptake property which signifies increase in ion exchange capacity(IEC) and proton conductivity as presence of acidic groups were characterized. These fabricated membranes performances were assessed in microbial fuel cells(MFCs) and characterized using XRD and FTIR for its compositional analysis. Due to proper proton conducting channelsmost suitable CEM (SPVA-PGO-3) revealed higher proton conductivity 9.0 x 10-2 S/cm at 27oC, water uptake 114%, area swelling 54.2% and ion exchange capacity (IEC) 1.92 meq/g. The power density obtained for this composite membrane applied in MFC-3 was observed to be 503.1 mW/m2 while the COD removal results obtained as 80.8 %.


2020 ◽  
Vol 16 ◽  
Author(s):  
Mohd Imran Ahamed ◽  
Nimra Shakeel ◽  
Naushad Anwar ◽  
Lutfullah ◽  
Anish Khan

: In this work, we demonstrate the synthesis of Kraton ionomer membrane by solution casting method. Kraton ionomer membrane was coated with polyaniline by in situ oxidative chemical polymerization to get electrical conductance in the membrane. The synthesized composite membrane of Kraton/polyaniline ionomer further characterized by electrochemical studies to check the redox properties of the material. Similarly, the ion exchange capacity and proton conductivity and selectivity of the synthesized membrane was also determined. From the selectivity studies which shows that the membrane was selective for Cu (II) ions. Furthermore, the outcomes of the membrane such as high ion exchange capacity, good proton conductivity, and efficient selectivity, displays the synthesized membrane is efficient for the preparation of ion-selective membrane electrode. The minimum concentration range of Cu (II) ions towards the ion-selective membrane was 1 × 10-1 to 1 × 10-8 M. The electrode revealed a Nernstian slope of 28.15 mV/decade change in concentration of Cu (II) ions. In addition, the electrode exposed fast response time of 10s, working pH range of 3-6.5, detection limit of 1 × 10-9 M and appreciably good selectivity towards Cu (II) ions over alkali, alkaline, and other heavy metal ions. Moreover, it can be employed as indicator electrode for the potentiometric titration of Cu (II) ions by using ethylene diamine tetraacetic acid, disodium salt (EDTA).


2013 ◽  
Vol 860-863 ◽  
pp. 803-806 ◽  
Author(s):  
Loh Kee Shyuan ◽  
Eng Lee Tan ◽  
Wan Ramli Wan Daud ◽  
Abu Bakar Mohamad

A diverse sulfonated polybenzimidazole copolymer (SPBI) as proton exchange membrane was synthesiszed via one-step high temperature polymerization method with 3,3-diaminobenzidine (DABD), 5-sulfoisophthalic acid (SIPA), 4,4-sulfonyldibenzoic acid (SDBA) and biphenyl-4,4-dicarboxylic acid (BDCA). The SPBI membrane was prepared through a direct hot-casting and in situ phase inversion technique. Characterization tests were carried out on the membranes including surface morphology, distribution of elements on the membrane, determination of functional groups, thermal stability, ion exchange capacity, water uptake rate and proton conductivity. The as-synthesized SPBI membrane displayed a smooth surface via scanning electron microscopy (SEM) analysis which is thermally stable up to 443 °C. The SPBI membrane showed higher water uptake rate (WUR) and proton conductivity though it had lower ion exchange capacity (IEC) value compared to recast Nafion membrane. The proton conductivity of the SPBI membrane with IEC of 0.60 mmol/g was 4.50 × 10-2 S/cm at 90 °C. This study shows that the SPBI membrane has great potential in polymer exchange membrane fuel cell (PEMFC) applications.


1992 ◽  
Vol 57 (9) ◽  
pp. 1905-1914
Author(s):  
Miroslav Bleha ◽  
Věra Šumberová

The equilibrium sorption of uni-univalent electrolytes (NaCl, KCl) in heterogeneous cation exchange membranes with various contents of the ion exchange component and in ion exchange membranes Ralex was investigated. Using experimental data which express the concentration dependence of equilibrium sorption, validity of the Donnan relation for the systems under investigation was tested and values of the Glueckauf inhomogeneity factor for Ralex membranes were determined. Determination of the equilibrium sorption allows the effect of the total content of internal water and of the ion-exchange capacity on the distribution coefficients of the electrolyte to be determined.


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