Thermal stability of ion-exchange Nafion N117CS membranes

Iwai, Yasunori; Yamanishi, Toshihiko

doi:10.1016/j.polymdegradstab.2008.12.020

Cited by 54 publications

(50 citation statements)

References 7 publications

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“…The decreased thermal stability observed for the composite membranes with respect to pristine Nafion cannot be attributed to the Lewis acid character of the Al 3+ ion which is known to catalyze the degradation of Nafion ether bonds only in Al exchanged membranes [44,47]. But, the gradual increase of weight loss observed during the first stage seems to indicate that the Faujasite accelerates the thermal degradation of the sulfonic acid groups.…”

Section: Nafion-faujasite Composite Membranesmentioning

confidence: 86%

On the proton conductivity of Nafion–Faujasite composite membranes for low temperature direct methanol fuel cells

Zhang

Désilets

Felice

et al. 2011

Journal of Power Sources

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a b s t r a c tAlthough zeolites are introduced to decrease methanol crossover of Nafion membranes for direct methanol fuel cells (DMFCs), little is known about the effect of their intrinsic properties and the interaction with the ionomer. In this work, Nafion-Faujasite composite membranes prepared by solution casting were characterized by extensive physicochemical and electrochemical techniques. Faujasite was found to undergo severe dealumination during the membrane activation, but its structure remained intact. The zeolite interacts with Nafion probably through hydrogen bonding between Si-OH and SO 3 H groups, which combined with the increase of the water uptake and the water mobility, and the addition of a less conductive phase (the zeolite) leads to an optimum proton conductivity between 0.98 and 2 wt% of zeolite. Hot pressing the membranes before their assembling with the electrodes enhanced the DMFC performance by reducing the methanol crossover and the serial resistance.

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Section: Nafion-faujasite Composite Membranesmentioning

confidence: 86%

On the proton conductivity of Nafion–Faujasite composite membranes for low temperature direct methanol fuel cells

Zhang

Désilets

Felice

et al. 2011

Journal of Power Sources

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“…Iwai and Yamanishi [14] have reported that cations with larger ionic radii show higher thermal stability when reacted with Nafion and Zirconia is a metal oxide with large molecular radius. Therefore, the composite membranes have higher thermal retention as a higher temperature is needed to activate the energy barrier and break the bond.…”

Section: Thermal Propertiesmentioning

confidence: 99%

Thermal Properties and Conductivity of Nafion-Zirconia Composite Membrane

Mokhtaruddin

Mohamad

Loh³

et al. 2016

MJAS

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The application of composite membranes for high temperature polymer electrolyte membrane fuel cell has attracted interests. Nafion-metal dioxide composite membranes are considered among the research niche. In this study, Nafion membranes and Nafion-zirconia composite membranes with 1, 3 and 5 wt. % of hydrous zirconia were prepared accordingly. All membranes were characterized by quantitative analysis techniques such as thermogravimetry analyse, diffraction scanning calorimetry and Fourier transform infrared. All composite membranes showed high glass transition temperatures and improved water retention properties, compared to the Nafion membrane. The composite membrane with 3 wt. % of zirconia showed the highest thermal resistance at 90°C.Keywords: high temperature PEM, glass transition temperature, conductivity, composite membrane, Nafion-zirconia Abstrak Penggunaan membran komposit dalam operasi sel bahanapi membran penukar proton pada suhu tinggi semakin mendapat perhatian pengkaji. Membran komposit Nafion-logam dioksida adalah antara bidang kajian dalam kumpulan ini. Bagi kajian ini, membran Nafion dan membran komposit Nafion-zirkonia dengan 1, 3, dan 5 wt. % telah disediakan. Kesemua membran dicirikan menggunakan teknik analisis kuantitatif seperti analisis termogravimetri, kalorimetri imbasan kerbedaan dan Fourier inframerah. Kesemua membran komposit mempunyai suhu peralihan kaca yang tinggi dan keupayaan penahanan air yang lebih baik berbanding membran Nafion. Membran komposit dengan 3 wt. % zirkonia menunjukkan ketahanan suhu tinggi pada suhu operasi 90°C.Kata kunci: PEM suhu tinggi, suhu peralihan kaca, konduktiviti, membran komposit, Nafion-zirkonia Introduction Fuel cells are electrochemical devices which convert the energy from the reaction of fuel and oxygen into electric energy continuously with water and CO 2 as the byproducts [1]. Polymer electrolyte membrane fuel cell (PEMFC) is one of the fuel cell types, for temperature ranging from 60 -100 °C. Nafion membranes are the most commonly used polymer electrolytes in PEMFC application as it has excellent chemical, mechanical and electrochemical properties as well as high proton conductivity at ambient temperature and high humidity condition. This waterbased electrolyte needs to be kept in a hydrated condition for the best performance and a maximum conductivity of 0.083 S/cm at 100% relative humidity (RH) [2].

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“…The effect of exchanged ions on the thermal stability of Nafion N117CS membranes was investigated by Iwai and Yamanishi [28]. They showed that as for the Nafion membrane when it was ion-exchanged with divalent ions or trivalent ions, its thermal stability was proportional to the increase in the ionic radius of the exchanged cations.…”

Section: Dsc Analysismentioning

confidence: 99%