scholarly journals Volumetric analysis technique for analyzing the transport properties of hydrogen gas in cylindrical-shaped rubbery polymers

2021 ◽  
pp. 107147
Author(s):  
Jae Kap Jung ◽  
In Gyoo Kim ◽  
Sang Koo Jeon ◽  
Kyu-Tae Kim ◽  
Un Bong Baek ◽  
...  
Keyword(s):  
Transport Properties ◽  
Volumetric Analysis ◽  
Hydrogen Gas ◽  
Analysis Technique ◽  
Rubbery Polymers

CHARACTERIZING THE HYDROGEN TRANSPORT PROPERTIES OF RUBBERY POLYMERS BY GRAVIMETRIC ANALYSIS

2021 ◽  
Author(s):  
Jae Kap Jung ◽  
In Gyoo Kim ◽  
Sang Koo Jeon ◽  
Ki Soo Chung
Keyword(s):  
Transport Properties ◽  
High Pressures ◽  
Hydrogen Gas ◽  
Ex Situ ◽  
Total Charge ◽  
Hydrogen Energy ◽  
Gravimetric Analysis ◽  
Butadiene Rubber ◽  
Sample Shape ◽  
Rubbery Polymers

ABSTRACT We develop an ex situ technique to quantitatively analyze the transport properties of hydrogen gas dissolved under high pressure in rubbery polymers, such as cylindrical and spherical samples of nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM), and fluoroelastomer (FKM), which are potential sealing materials for hydrogen energy infrastructures. The technique consists of real-time gravimetric measurements during the desorption of hydrogen gas from samples using an electronic balance and a self-developed analysis program to determine the total charge (CH0), diffusivity (D), solubility (S) and permeability (P) of hydrogen. Dual absorption behavior is found for all three rubbers as the charging pressure increases. CH0 follows Henry's law at low pressures of up to ∼25 MPa, whereas the Langmuir model applies at high pressures. No significant pressure, size, or shape dependences are observed for D and P. The measured P values are consistent with those from the literature within the combined uncertainty evaluated. The effect of a carbon black filler mixed into rubber is discussed with respect to S and D. This method can be applicable as a standard test for the transport properties versus the pressure of various polymers irrespective of sample shape.

scholarly journals Volume Dependence of Hydrogen Sorption and Desorption Diffusion in Cylindrical Polymers

2021 ◽  
Author(s):  
Jae Kap Jung ◽  
Kyu-Tae Kim ◽  
Un Bong Baek ◽  
Seung Hoon Nahm
Keyword(s):  
Diffusion Coefficient ◽  
Hydrogen Diffusion ◽  
Chain Scission ◽  
Volumetric Analysis ◽  
Cylindrical Sample ◽  
Desorption Process ◽  
Hydrogen Molecules ◽  
Volume Dependence ◽  
Analysis Technique ◽  
Volume Swelling

Abstract We have investigated the volume effects on hydrogen diffusion properties in both sorption and desorption processes by employing a volumetric analysis technique. The total uptake (𝐶∞), total desorbed content (𝐶0), sorption diffusion coefficient (Ds), desorption diffusion coefficient (Dd), sorption and desorption equilibrium time of hydrogen in two rubbery polymers are determined relative to the diameter and thickness of the cylindrical sample in the two processes. 𝐶∞ and 𝐶0 do not demonstrate the appreciable volume dependence for all rubbers. The identical values in 𝐶∞ and 𝐶0 indicate the reversibility between sorption and desorption, which is interpreted by the occurrence of physisorption rather than chemisorption by introducing hydrogen molecules. The larger Dd values in the desorption process than Ds may be attributed to increased amorphous phase and volume swelling caused by increased hydrogen voids and polymer chain scission after decompression. The time to reach equilibrium in both sorption and desorption processes was found to be linearly proportional to the square of thickness above an aspect ratio of 3.7, which is consistent with the numerical simulations based on the solution of Fick’s law. This finding could be used to predict the equilibrium adsorption time depending on the sample size in the polymer.

Transport properties of proton conducting phosphate glass: An electrochemical hydrogen pump enabling the formation of dry hydrogen gas

2019 ◽  
Vol 44 (45) ◽  
pp. 24977-24984 ◽  
Author(s):  
Tomohiro Ishiyama ◽  
Haruo Kishimoto ◽  
Katsuhiko Yamaji ◽  
Takuya Yamaguchi ◽  
Junji Nishii ◽  
...  
Keyword(s):  
Transport Properties ◽  
Phosphate Glass ◽  
Hydrogen Gas ◽  
Proton Conducting ◽  
Hydrogen Pump

Novel volumetric analysis technique for characterizing the solubility and diffusivity of hydrogen in rubbers

2021 ◽  
Vol 26 ◽  
pp. 9-15
Author(s):  
Jae Kap Jung ◽  
In Gyoo Kim ◽  
Kyu-Tae Kim ◽  
Un Bong Baek ◽  
Seung Hoon Nahm
Keyword(s):  
Volumetric Analysis ◽  
Analysis Technique

scholarly journals Combined laser-based X-ray fluorescence and particle-induced X-ray emission for versatile multi-element analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pilar Puyuelo-Valdes ◽  
Simon Vallières ◽  
Martina Salvadori ◽  
Sylvain Fourmaux ◽  
Stephane Payeur ◽  
...  
Keyword(s):  
Detection Threshold ◽  
Volumetric Analysis ◽  
Intense Laser ◽  
Element Analysis ◽  
Fast Analysis ◽  
X Ray ◽  
Analysis Technique ◽  
Radiation Sources ◽  
Non Destructive ◽  
Multi Element Analysis

AbstractParticle and radiation sources are widely employed in manifold applications. In the last decades, the upcoming of versatile, energetic, high-brilliance laser-based sources, as produced by intense laser–matter interactions, has introduced utilization of these sources in diverse areas, given their potential to complement or even outperform existing techniques. In this paper, we show that the interaction of an intense laser with a solid target produces a versatile, non-destructive, fast analysis technique that allows to switch from laser-driven PIXE (Particle-Induced X-ray Emission) to laser-driven XRF (X-ray Fluorescence) within single laser shots, by simply changing the atomic number of the interaction target. The combination of both processes improves the retrieval of constituents in materials and allows for volumetric analysis up to tens of microns and on cm2 large areas up to a detection threshold of ppms. This opens the route for a versatile, non-destructive, and fast combined analysis technique.

scholarly journals The effect of electric transport properties of titanium dioxide nanostructures on their photocatalytic activity

2020 ◽  
Vol 99 (3) ◽  
pp. 13-21
Author(s):  
T.M. Serikov ◽  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Transport Properties ◽  
Tetragonal Phase ◽  
Capillary Condensation ◽  
Titanium Dioxide Nanoparticles ◽  
Hydrogen Gas ◽  
Blue Dye ◽  
Xenon Lamp ◽  
Electric Transport

. Films formed by nanoparticles, nanorods and nanotubes of titanium dioxide with a thickness of 3.9, 4.0 and 4.1 μm, respectively, with an area of 2 cm2 were obtained by various methods. Nanostructures were characterized by X-ray phase analysis, scanning electron microscopy (SEM), BET (Brunauer–Emmett–Teller), BJH (Barrett–Joyner–Halenda). The electric transport properties of the films were studied by impedance pectroscopy. The photocatalytic activity of the samples was evaluated by the photocurrent and degradation of the methylene blue dye under xenon lamp illumination. The concentration of hydrogen released per unit time was determined by gas chromatography in a standard quartz cuvette using a platinum electrode. The study of texture characteristics showed that the obtained isotherms belong to type IV isotherms with a hysteresis loop, reflecting the process of capillary condensation in mesopores. The diffraction peaks for the films of nanoparticles and nanotubes of titanium dioxide are identical and correspond to the tetragonal phase of anatase, for films of nanorods to the tetragonal phase of rutile. When studying the electric transport properties of films, it was found that films of titanium dioxide nanoparticles have a higher resistance associated with unformed bonds between nanoparticles. Despite the low specific surface area, titanium dioxide nanorods showed higher photocatalytic activity than nanotubes and nanoparticles. The results are confirmed by measurements of photocurrent, dye decomposition and the splitting of water molecules into hydrogen gas and oxygen.

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

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