Free volume, oxygen permeability, and uniaxial compression storage modulus of hydrated biphenol-based sulfonated poly(arylene ether sulfone)

Hamed, Mohamed; Kobayashi, Yoshinori; Kuroda, Carlos Seiti; Takimoto, Naohiko; Ohira, Akihiro

doi:10.1016/j.memsci.2010.05.003

Cited by 23 publications

(18 citation statements)

References 51 publications

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“…The right y ‐axis of the top figure shows the hole volume size V f which is calculated using Equations (15, 16). The behavior of the o‐ Ps lifetime τ 3 (hole volume size V f ) with the relative humidity can be divided for all the membranes into two regions; 1) At low RH, τ 3 decreases with increasing RH as a result of the filling of the hole volume with water molecules similar to the data of Mohamed et al 62,63 So, intermolecular spaces in the membrane could be filled with the water molecules, which is seen as the reason for a slight decrease in the hole volume. The present data also agrees with the data of Barique et al 64 The minimum hole volume size is at relative humidity 25%, 10%, and 20% for F‐14100, F‐1050, and F‐950 membranes, respectively, which is not correlated with IEC of the membrane.…”

Section: Resultssupporting

confidence: 64%

Humidity effect on the transport properties of per‐fluorinated sulfonic acid/PTFE proton exchange membranes: Positron annihilation study

El-Sharkawy

Mohamed

Hassanien

et al. 2021

Polymers for Advanced Techs

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The positron annihilation lifetime (PAL) technique was used to investigate the yield and lifetime of positronium (Ps) in three different samples of per‐fluorinated sulfonic acid/polytetrafluoroethylene (PTFE) proton exchange membranes. The high probability of Ps formation enables the study of the hole volume size by the PAL technique and explains the mechanism of both methanol permeation and proton conductivity of the membranes in relation to the relative humidity (RH). The influence of various membrane parameters, including water uptake, proton conductivity, and mechanical properties, was studied. The concentration of water molecules and SO3−–H3O+groups is correlated with the ion exchange capacity (IEC) of the membranes where higher IEC leads to high absorbance of water. The proton conductivity is enhanced by increasing the IEC value of the membrane. The activation energies of decomposition temperature for the F‐950 membrane are the lowest (Eb = 2.856 and 1.030 eV for the 1st and 2nd decomposition peaks, respectively, implying that the membrane with high IEC is thermally less stable. With increasing the IEC of the membranes, the concentration of the water molecules/SO3 group increases. In addition, the proton conductivity of the membrane is positively influenced by increasing water content at high RH. The fact that the variations in hole volume size and both methanol permeability and proton conductivity are highly dependent on RH suggests that hole volume size plays an important role in many parameters of hydrated perfluorinated sulfonic acid/PTFE proton exchange membranes. The outcomes data were introduced and interpreted appropriately with a theoretical model and compared with the literature.

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Section: Resultssupporting

confidence: 64%

Humidity effect on the transport properties of per‐fluorinated sulfonic acid/PTFE proton exchange membranes: Positron annihilation study

El-Sharkawy

Mohamed

Hassanien

et al. 2021

Polymers for Advanced Techs

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“…Average hydrogen crossover rate is 1.46 Â 10 À9 mol cm À2 s À1 and 2.92 Â 10 À9 mol cm À2 s À1 for SPAES-50 and fSPAES-70, respectively. Hydrogen crossover rate of fSPAES-70 is approximately twice that of SPAES-50 and this trend coincides with gas permeability results of SPAES (2.5 Â 10 À13 cm 3 cm cm À2 s À1 Pa À1 ) and fSPAES (6 Â 10 À13 cm 3 cm cm À2 s À1 Pa À1 ) reported in previous literature [18,24]. Polymer characteristics evaluated through d-spacing measurements and hydrogen crossover clearly show that fSPAES-70 has relatively advantageous characteristics suitable for binder application compared to SPAES-50.…”

Section: Polymer Characteristicssupporting

confidence: 90%

“…Bae et al introduced bulky hydrophobic components to the polymer backbone and showed that increased free volume contributes to higher gas permeability [18]. Also Mohamed et al claimed that the inter-chain open space or free volume is necessary for gas permeation [24]. Thus inter-chain spacing of polymers is a useful parameter to consider when choosing catalyst layer binders.…”

Section: Polymer Characteristicsmentioning

confidence: 99%

Modification of hydrocarbon structure for polymer electrolyte membrane fuel cell binder application

Yoon¹,

Kim²,

Yu³

et al. 2012

International Journal of Hydrogen Energy

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“…Positron annihilation spectroscopy (PAS) has been generally connected to polymeric solids, especially to polyethylene. The impact of various physical parameters, for example, crystallinity, thickness, temperature, weight, electric or attractive field, light portion, and so forth, have been analyzed inside this setting to think about structural changes and fundamentally to recognize the starting point of the different lifetime parts . A small number of lively positrons, embedded into a polymer, by and large, structure the bound state with an electron, positronium (Ps).…”

Section: Introductionmentioning

confidence: 99%

Study of the nanostructure of γ‐irradiated high‐density polyethylene/carbon black composite and its durability as geomembrane

Taha

Hamed

2020

Polymers for Advanced Techs

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The degradation of the nearby generation of high-density polyethylene (HDPE) loaded with 2.5% of carbon black (CB) content (ie, HDPE/CB composites) is studied experimentally with the end goal of radiation safety applications. The impact of various γ-irradiation doses in the air on the nanostructure of free volume and durability has been researched. The free volume was evaluated utilizing the positron annihilation lifetime (PAL) technique while the durability was contemplated by measuring the mechanical properties such as strain, elongation at break, and tear resistance. The electrical conductivity was explored to demonstrate the impact of the irradiation dose on the conductivity of the samples. Surface morphology studies using a scanning electron microscope (SEM) showed the surface fracture of HDPE/CB composites for unirradiated and irradiated samples. The surface roughness of the HDPE/CB GMs increases with increasing the irradiation dose. Among various uses of HDPE/CB composites, sheets are liners of dumps used to dispose of interim storage for Low and Medium Level Waste of NORMs and TENORMs. HDPE Geomembrane liners proved its utilization from the results of present research of electrical, mechanical tests, and SEM morphology to have the required resistance to weather conditions.

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Free volume, oxygen permeability, and uniaxial compression storage modulus of hydrated biphenol-based sulfonated poly(arylene ether sulfone)

Cited by 23 publications

References 51 publications

Humidity effect on the transport properties of per‐fluorinated sulfonic acid/PTFE proton exchange membranes: Positron annihilation study

Humidity effect on the transport properties of per‐fluorinated sulfonic acid/PTFE proton exchange membranes: Positron annihilation study

Modification of hydrocarbon structure for polymer electrolyte membrane fuel cell binder application

Study of the nanostructure of γ‐irradiated high‐density polyethylene/carbon black composite and its durability as geomembrane

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