Synthesis and protonic conductivity of the oligomeric amides with different average molecular weights

Nagao, Yuki; Haneda, Aya; Naito, Nobuhiro; Iguchi, Fumitada; Sata, Noriko; Yugami, Hiroo

doi:10.1016/j.ssi.2008.01.051

Cited by 5 publications

(4 citation statements)

References 12 publications

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“…Proton conductive polymers do not usually exhibit a strong effect of molecular weight for proton conductivity when the molecular weight is greater than a few thousand values. 115,116 However, the SPI thin films show a strong correlation between the molecular weight and proton conductivity. 32 Analyses of the thin films by GISAXS reveal that the HM w (M w = 2.6 × 10 5 ) SPI film exhibits a higher degree of inherent liquid -crystallinelike lamellar ordering than the LM w (M w = 1.3 × 10 4 ) SPI film does, as shown in Figure 7a,b.…”

Section: ■ Introductionmentioning

confidence: 99%

Proton-Conductivity Enhancement in Polymer Thin Films

Nagao

2017

Langmuir

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Highly proton conductive polymers have long attracted the attention of researchers for use in energy conversion, sensors, catalysts, and other applications. From the viewpoint of the scientific history of the creation of highly proton conductive polymers, one fundamental approach is based on the strategy of phase-segregated structures with strong acid groups. This Feature Article presents a new approach to enhancing the proton conductivity of the polymer thin films using an interface that can modify the degrees of freedom for a polymer structure through interaction between the substrate surface and polymers. I introduce suppressed proton conductivity into Nafion thin films and then specifically examine the enhancement in proton conductivity by the molecular orientation of the polymers. As the last topic, a highly proton conductive organized polyimide thin film is demonstrated using the lyotropic liquid-crystal property. Both molecular ordering and the in-plane oriented structure can enhance proton conductivity. Moreover, the optical domain and degree of molecular ordering derived from the molecular weight can contribute strongly to the proton transport property.

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Section: ■ Introductionmentioning

confidence: 99%

Proton-Conductivity Enhancement in Polymer Thin Films

Nagao

2017

Langmuir

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“…[4][5][6][7][8][9] Many studies have published proton transport improvement in an anhydrous state using acid-base combinations of proton conductors. [10][11][12][13][14][15][16] In this system, proton donors are acid groups with low pK a values because protons are readily dissociated. By contrast, the basic groups act as proton acceptors, this proton reception and release continue the transportation.…”

Section: Introductionmentioning

confidence: 99%

Interfacial and Internal Proton Conduction of Weak-acid Functionalized Styrene-based Copolymer with Various Carboxylic Acid Concentrations

et al. 2021

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Investigation of interfacial proton transport is necessary to elucidate biological systems. As commonly found in biomaterials, the carboxylic acid group was proven to act as a protonconducting group. This study investigated the influence of carboxylic acid concentration on both interfacial and internal proton transport. Several styrene-based polymers containing the carboxylic acid group were synthesized. The amount of carboxylic acid group in the polymer chain was varied to explore the effects of weak acid concentration on polymer thin films' electrical properties. The IR p-polarized multiple-angle incidence resolution spectrometry (pMAIR) spectra show the higher ratio of the free carboxylic acid groups rather than cyclic dimers in polymers with a higher concentration of carboxylic acid group, facilitating the more hydrogen bonding networks in films. The water uptake results reveal the similar number of adsorbed water molecules per carboxylic acid group in all thin films. Remarkably, polymer thin films with high carboxylic acid concentration provide internal proton conduction because of the relative increase in the amount of the free carboxylic acid group. In contrast, interfacial proton conduction was found in low carboxylic acid concentration polymers because of the relatively large amount of cyclic dimer carboxylic acid group and poor amount of free carboxylic acid group. This study provides insight into interfacial proton transport behavior according to the weak acid concentration, which might explain proton transport in biological systems.

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“…The amide groups exhibit the proton exchange property because of the amide/imidic acid tautomerism. We have investigated a series of the proton-conductive oligomers containing amide groups [18,19]. In this paper, we synthesized proton-conductive polyamide oligomers, oligomeric poly[(1, 2-propanediamine)-alt-(oxalic acid)], and investigated the proton transport properties of the thin film on another substrate (sapphire substrate) to study the enhancement of the proton conductivities.…”

Section: Introductionmentioning

confidence: 99%

Proton Conductivity of Oligomeric Poly[(1,2-Propanediamine)-alt-(Oxalic Acid) Thin Films on Al2O3 Substrates

Nagao

Naito

Iguchi

et al. 2009

e-J. Surf. Sci. Nanotechnol.

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Proton transport properties of three thin films (110, 240, and 360 nm thick films) on R-plane (1102) sapphire substrates for oligomeric poly[(1, 2-propanediamine)-alt-(oxalic acid)] were investigated. The maximum proton conductivity of the thin film is 1.7 × 10 −3 S cm −1 at the RH of 80%, which is five times higher than that of the bulk sample (3.0 × 10 −4 S cm −1 ). The activation energies of the 110, 240, and 360 nm thick films are found to 0.74, 0.67, and 0.68 eV at the RH of 80%, respectively.

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Synthesis and protonic conductivity of the oligomeric amides with different average molecular weights

Cited by 5 publications

References 12 publications

Proton-Conductivity Enhancement in Polymer Thin Films

Proton-Conductivity Enhancement in Polymer Thin Films

Interfacial and Internal Proton Conduction of Weak-acid Functionalized Styrene-based Copolymer with Various Carboxylic Acid Concentrations

Proton Conductivity of Oligomeric Poly[(1,2-Propanediamine)-alt-(Oxalic Acid) Thin Films on Al2O3 Substrates

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