PFG-NMR approach to determining the water transport mechanism in polymer electrolyte membranes conditioned at different temperatures

Kidena, Koh; Ohkubo, Takahiro; Takimoto, Naohiko; Ohira, Akihiro

doi:10.1016/j.eurpolymj.2009.12.012

Cited by 44 publications

(51 citation statements)

References 34 publications

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“…The bulk, or infinite, diffusion coefficient is taken as the diffusion coefficient at the largest Δ and was equal to 1.6 × 10 −5 cm 2 s −1 . These values are relatively high compared to diffusion coefficients reported for Nafion™ which are generally <1 × 10 −5 cm 2 s −1 . The high diffusion through the membrane may indicate a different long range ordering in the quaternary ammonium membranes compared to PFSA membranes.…”

Section: Resultsmentioning

confidence: 61%

Synthesis and characterization of perfluoro quaternary ammonium anion exchange membranes

Vandiver

Horan

Yang

et al. 2012

J Polym Sci B Polym Phys

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In this study, new alkaline exchange membranes were prepared from the perfluorinated 3M ionomer with various quaternary ammonium cations attached with sulfonamide linkage. The degree of functionalization varied depending on the cation species, resulting in different ion exchange capacities (IECs), 0.33–0.72 meq g−1. There was evidence of polymer degradation when the films were exposed to hydroxide, and hence all membrane characterization was performed in the chloride form. Conductivity was dependent on cation species and IEC, Ea = 36–59 kJ mol−1. Diffusion of water through the membrane was relatively high 1.6 × 10−5 cm2 s−1 and indicated restriction over a range of diffusion times, 6–700 ms. Water uptake (WU) in the membranes was generally low and the hydration level varied based on cation species, λ = 6–11. Small‐angle scattering experiments suggested ionic aggregation, 37–42 Å, independent of cation species but slight differences in long‐range order with cation species. © 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1761–1769, 2013

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Section: Resultsmentioning

confidence: 61%

Synthesis and characterization of perfluoro quaternary ammonium anion exchange membranes

Vandiver

Horan

Yang

et al. 2012

J Polym Sci B Polym Phys

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“…The fitted short‐term phase decay time τ 1 is 410 ms and long‐term phase decay time τ 2 is 2710 ms, respectively. [12,24a] The inset of Figure d shows the influence of pulse width on PPF index, which increases exponentially from 5% to 97% as the pulse width increased from 10 ms to 1 s. Given that the latter spike is reinforced by the residual migration species triggered by the former spike, which do not have sufficient time to diffuse back, both shorter interval and wider width are favorable for the facilitation . Figure e exhibits the PPF index and post‐tetanic potentiation index (PTP, ( A 10 − A 1)/ A 1) with respect to different temperatures.…”

Section: Resultsmentioning

confidence: 99%

Bioinspired Artificial Sensory Nerve Based on Nafion Memristor

Zhang

Zhou

et al. 2019

Adv Funct Materials

244

230

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Bioinspired artificial haptic neuron system has received much attention in the booming artificial intelligence industry for its broad range of high-impact applications such as personal healthcare monitoring, electronic skins, and human-machine interfaces. An artificial haptic neuron system is designed by integrating a piezoresistive sensor and a Nafion-based memristor for the first time in this paper. The piezoresistive sensor serves as a sensory receptor to transform mechanical stimuli into electric signals, and the Nafion-based memristor serves as the synapse to further process the information. The pyramid-structured sensor exhibits excellent sensitivity (6.7 × 10 7 kPa −1 in 1-5 kPa and 3.8 × 10 5 kPa −1 in 5-50 kPa) and durability (>7000 cycles), while the memristor realizes fundamental synaptic functions under low power consumption (10-200 pJ) and remains stable for over 10 4 consecutive tests. The integrated system can detect tactile stimuli encoded with temporal information, such as the count, frequency, duration and speed of the external force. As a proof-of-concept, English characters recognition with high accuracy can be achieved on the system under a supervised learning method. This work shows promising potential in bioinspired sensing systems owing to the high performance, excellent durability, and simple fabrication procedure.

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“…Pulsed field gradient NMR was used for evaluating diffusion coefficients in situ, conditioning samples at determined values of temperature and relative humidity [60]. Two types of membranes were examined: Nafion NR-212 and sulfonated poly(4-phenoxybenzoyl-1,4-phenylene) (SPPBP).…”

Section: Polymeric Proton Conductorsmentioning

confidence: 99%

Diffusion in Solid Proton Conductors: Theoretical Aspects and Nuclear Magnetic Resonance Analysis

Vona

Sgreccia

Tosto

2012

Solid State Proton Conductors

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Water behavior in solid proton conductors is a considerably complex phenomenon. However, the knowledge of transport and diffusivity inside electrolytes is an important requirement for many applications. Extensive efforts have been made in terms of modeling water transport and its management. Accurate measurements of diffusion are required to validate these models and to optimize the performance of solid proton conductors.The focus of this chapter is the theoretical approach together with the use of nuclear magnetic resonance (NMR) techniques for the understanding of diffusion phenomena in solid proton conductors. The basic principles and the main NMR methods will be also discussed.

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PFG-NMR approach to determining the water transport mechanism in polymer electrolyte membranes conditioned at different temperatures

Cited by 44 publications

References 34 publications

Synthesis and characterization of perfluoro quaternary ammonium anion exchange membranes

Synthesis and characterization of perfluoro quaternary ammonium anion exchange membranes

Bioinspired Artificial Sensory Nerve Based on Nafion Memristor

Diffusion in Solid Proton Conductors: Theoretical Aspects and Nuclear Magnetic Resonance Analysis

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