SAXS/WAXS characterization of proton-conducting polymer membranes containing phosphomolybdic acid

Prado, L.; Ponce, Mariela L.; Funari, Sérgio S.; Schulte, Karl; Garamus, Vasil M.; Willumeit‐Römer, Regine; Nunes, Suzana Pereira

doi:10.1016/j.jnoncrysol.2005.06.007

Cited by 15 publications

(7 citation statements)

References 35 publications

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“…SAXS is a useful technique for investigations of the structure and morphology of polymeric ionomer membranes. , A unified fit model can be used to confirm the structures of the films as a function of HPA loading and RH . The application of this unified function to the SAXS pattern of a typical polyPOM membrane is illustrated in Figure e.…”

Section: Resultsmentioning

confidence: 99%

Fast Proton Conduction Facilitated by Minimum Water in a Series of Divinylsilyl-11-silicotungstic Acid-co-Butyl Acrylate-co-Hexanediol Diacrylate Polymers

Horan¹,

Lingutla²,

Ren³

et al. 2013

J. Phys. Chem. C

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Studies of proton transport in novel materials are important to enable a large array of electrochemical devices. In this study, we show that heteropoly acids (HPAs) when immobilized in polymer matrixes have highly mobile protons. Divinyl-11-silicotungstic acid, an HPA, was copolymerized with butyl acrylate and hexanediol diacrylate at various weight percentage loadings from 25% to 85% using UV initiated polymerizations. The resultant films were tan colored flexible sheets of ca. 120 μm thickness. The morphology of these films varied with loading, showing phase separation into clustered HPA above a 50 wt % loading and lamella morphologies above an 80 wt % loading. Water uptake was strongly associated with the HPA clusters, which facilitated transport of protons. This was realized by proton conductivities as high as 0.4 S cm −1 at 95 °C and 95% RH and 0.1 S cm −1 at 85 °C and 50% RH. Pulse field gradient spin echo NMR measurements indicated that water selfdiffusion was fast (1.4 × 10 −5 and 4.4 × 10 −5 cm 2 s −1 for 50% and 100% RH, respectively) at 80 °C. We show that the water in these systems is highly associated with the HPA clusters and that fast proton transport is facilitated by as few as 3 water molecules per proton.

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Section: Resultsmentioning

confidence: 99%

Fast Proton Conduction Facilitated by Minimum Water in a Series of Divinylsilyl-11-silicotungstic Acid-co-Butyl Acrylate-co-Hexanediol Diacrylate Polymers

Horan¹,

Lingutla²,

Ren³

et al. 2013

J. Phys. Chem. C

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“…SAXS analysis of sulfonated poly(aryl ether ketone) (SPEEK)/phosphomolybdic acid (PMoA) membranes (a), and pristine SPEEK membranes (b)[80].Membranes 2020, 10,33 15 of 37…”

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confidence: 99%

Microscopy and Spectroscopy Techniques for Characterization of Polymeric Membranes

Alqaheem

Alomair

2020

Membranes

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Polymeric membrane is a proven technology for water purification and wastewater treatment. The membrane is also commercialized for gas separation, mainly for carbon dioxide removal and hydrogen recovery. Characterization techniques are excellent tools for exploring the membrane structure and the chemical properties. This information can be then optimized to improve the membrane for better performance. In this paper, characterization techniques for studying the physical structure such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) are discussed. Techniques for investigating the crystal structure such as X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and wide-angle X-ray scattering (WAXS) are also considered. Other tools for determining the functional groups such Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and nuclear magnetic resonance (NMR) are reviewed. Methods for determining the elemental composition such as energy-dispersion X-ray spectroscopy (EDS), X-ray fluorescent (XRF), and X-ray photoelectron spectroscopy (XPS) are explored. The paper also gives general guidelines for sample preparation and data interpretation for each characterization technique.

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“…This board peak, referred to here as the "semicrystalline peak," has also been confirmed by other studies using WAXS and X-ray diffraction. 44,45 The critical angle (α c ) for the thin film was inferred from the Q z parameter associated with the Yoneda peak, which is represented as a horizontal feature in the lower region of the spectra. The location of the Yoneda peak (Q z ≈ 0.02 Å −1 ) is described by the following equation, which was utilized to estimate α c .…”

Section: ■ Resultsmentioning

confidence: 99%

Annealing-Induced Heterogeneous Crystallization of Topologically Confined SPEEK Thin Films

Gao,

Guo,

Cui

et al. 2024

J. Phys. Chem. C

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Pt-supported SPEEK (sulfonated poly(ether ether ketone)) thin films, mimicking the ionomer−electrode interface in polymer electrolyte fuel cells (PEFCs), were synthesized with thicknesses from 12 to 105 nm. Their glass transition temperature (T g ) was analyzed via in situ thermal ellipsometry, revealing a thickness-dependent decrease in T g , indicative of confinement effects. Particularly, a 30 nm film, typical of practical ionomer films, exhibited surface crystallization preceding that at the buried interface, a phenomenon linked to higher mobility at the free surface, as confirmed by grazing incidence wide-angle X-ray scattering (GIWAXS) at both subcritical (0.09°) and supercritical (0.14°) angles. This study elucidates the dynamic interplay between the high-mobility-free surface and the interaction-intensive buried interface in confined SPEEK thin films. It was observed that below 30 nm thickness, interfacial interactions become the primary factor influencing transition temperature. Additionally, spatially heterogeneous crystallization, more pronounced in the outof-plane direction, correlates with reduced proton conduction, underscoring the impact of membrane electrolyte assembly (MEA) hot-pressing on the functional properties of Nafion alternatives.

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SAXS/WAXS characterization of proton-conducting polymer membranes containing phosphomolybdic acid

Cited by 15 publications

References 35 publications

Fast Proton Conduction Facilitated by Minimum Water in a Series of Divinylsilyl-11-silicotungstic Acid-co-Butyl Acrylate-co-Hexanediol Diacrylate Polymers

Fast Proton Conduction Facilitated by Minimum Water in a Series of Divinylsilyl-11-silicotungstic Acid-co-Butyl Acrylate-co-Hexanediol Diacrylate Polymers

Microscopy and Spectroscopy Techniques for Characterization of Polymeric Membranes

Annealing-Induced Heterogeneous Crystallization of Topologically Confined SPEEK Thin Films

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