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This study reports the pair distribution function (PDF) analysis of combined wide‐ and small‐angle X‐ray scattering (WAXS/SAXS) profiles of poly(styrene sulfonic acid) (PSSA) grafted poly(ethylene‐co‐tetrafluoroethylene) polymer electrolyte membranes (ETFE‐PEMs) within a wide grafting degree (GD) of 0%–117%. The PDF analysis of WAXS profiles (from Cu‐Kα1 radiation) provides a measure in size of the crystallite domains (5.1–8.7 nm). The extension of the PDF analysis for only SAXS profiles shows the distances of crystallite layers of 25.1–32 nm. In particular, SAXS‐PDF analysis is effective in showing the existence of newly generated graft domains with distances ≈60–64 nm, which can not be determined previously by the conventional SAXS analysis. The high similarity in local and higher‐order structures observed for polystyrene grafted ETFE films and ETFE‐PEMs suggests that the hierarchical structures including the spatial arrangement of large amorphous contents in the membranes can be determined at the graft polymerization step. Note that the presence of newly generated PSSA graft domains at large dimension can explain well the comparable or higher proton conductivity of ETFE‐PEMs as compared with commercial Nafion membrane. [ABSTRACT FROM AUTHOR]

Besides the most common methods of internal dose assessment from inhaled 131I, that are thyroid monitoring and urine analysis, air sampling is a possible way but rarely used for dose estimate. This study aimed to focus on the utilisation of portable air sampler to estimate the internal dose for workers working at 131I production facility. In addition, internal dose estimated from urine analysis at the same time was carried out for comparison. Based on this research, it was found that air monitoring can be done efficiently as urine monitoring if the following conditions are met: (1) the indoor areas are not large, (2) sampling sites need to be placed as near breathing zone as possible and (3) the time-micro-environment patterns of monitored workers are collected carefully. [ABSTRACT FROM AUTHOR]

Microstructural complexity in graft-type polymer electrolyte membranes upon operating conditions is still challenging for examination. Here, the phase separation and water channels of poly(styrene sulfonic acid) (PSSA)-grafted poly(ethylene-co-tetrafluoroethylene) (ETFE) polymer electrolyte membranes (ETFE-PEMs) are characterized by a newly applying method based on electron density fluctuation, F , in the small angle X-ray scattering (SAXS) profiles. The ETFE-PEMs exhibit an increase in phase separation in the ion exchange capacity of 0–0.7 mmol/g as qualitatively determined by the increase in the SAXS invariant. The increase in the SAXS invariant is attributed to the evolution of the newly separated phase between the surfaces of crystalline ETFE backbones and the side chains of PSSA grafts. This phase separation allows the formation of water channels upon low relative humidity (RH). The ionic-domain spacing is around 1.52 nm at dry condition and then increases to 1.69 nm at low RH of 10%, reflecting the ion-water aggregation to make larger aggregate size. At 30% relative humidity, the highly ordered lamellar proton-conducting nanochannels (water channels) are formed in the membrane, which correspond to the dramatic increase in proton conductivity. It is interesting to note that these conducting nanochannels remain unchanged upon 30–70% RH. Also, in this range of RH the similar signatures in the pair distribution function suggests that the molecular packing and local structures are highly similar. Above features of phase separation and water channels can elucidate important characteristics of the ETFE-PEMs, especially the high proton conductivity at low RH. [Display omitted] • The membranes show an increase in phase separation at low IECs of 0–0.7 mmol/g. • The highly ordered lamellar water channels are formed at RH = 30% and then remain unchanged. • Phase separation and water channels can elucidate the high proton conductivity at low RH of 30%. [ABSTRACT FROM AUTHOR]