Characterization technique of gases permeation properties in polymers: H2, He, N2 and Ar gas

Abstract

We demonstrate a simple experimental technology for characterizing the gas permeation properties of H2, He, N2 and Ar absorbed in polymers. This is based on the volumetric measurement of released gas and an upgraded diffusion analysis program after high-pressure exposure. Three channel measurements of sorption content of gases emitted from polymers after decompression are simultaneously conducted, and then, the gas uptake/diffusivity as a function of exposed pressure are determined in nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM) rubbers, low-density polyethylene (LDPE) and high-density polyethylene (HDPE), which are used for gas sealing materials under high pressure. The pressure-dependent gas transport behaviors of the four gases are presented and compared. Gas sorption follows Henry’s law up to 9 MPa, while pressure-dependent diffusion behavior is not observed below 6 MPa. The magnitude of the diffusivity of the four gases decreases in the order DHe > DH2 > DAr > DN2 in all polymers, closely related to the kinetic diameter of the gas molecules. The dependence of gas species on solubility is in contrast to that on diffusivity. The linear correlation between logarithmic solubility and critical temperature of the gas molecule was newly observed.

Catecholate Dye-Assisted Decoration of Ag on TiO2 Nanoparticles for Detection of Cancer-Related MicroRNA Biomarkers on a Multiplexed Photoelectrochemical Platform

“…The mass yield was calculated to be only 5.5%. The presence of N is attributed to the air plasma treatment of the ITO/PET substrates before deposition of TiO 2 /HTX-10/Ag-10, which results in surface adsorption of N 2 gas on the substrate …”

Review of Developed Methods for Measuring Gas Uptake and Diffusivity in Polymers Enriched by Pure Gas under High Pressure

“…The gas in the cylinder follows the ideal gas equation, PV = nRT , where is the gas constant, 8.20544 × 10 −5 m 3 ·atm/(mol·K), T is the absolute temperature of the gas in the upper part of the cylinder, and n is the mole number of the emitted gas in the cylinder. The time-dependent and of the gas in the cylinder are formulated as [ 27 , 29 , 31 ]: where is the atmospheric pressure outside the cylinder, is the density of the distilled water, g is gravitational acceleration, is the level (height) of the water volume in the cylinder based on the water level in the water container, is the total volume of both water and gas in the cylinder based on the water level in the water container, the time-varying is the water volume in the cylinder measured based on the water level in the water container, and is the specimen volume.…”

“…The residual concentration c ( t ) of the gas in the remaining mode for the spherical specimen is expressed as follows [ 29 , 33 ]. …”

“…Low-density polyethylene (LDPE) was also included as a specimen for experimental investigations. The composition and density of the specimens are listed in previous literatures [ 24 , 29 ]. NBR, EPDM, FKM, and LDPE specimens with cylindrical and spherical shapes are used.…”

Investigation of the Gas Permeation Properties Using the Volumetric Analysis Technique for Polyethylene Materials Enriched with Pure Gases under High Pressure: H2, He, N2, O2 and Ar

“…In this work, a volumetric analysis technique using a graduated cylinder that was recently developed by our group was used to measure the volume of gas released from gasenriched polymeric materials. This technique could compensate for the minute variations in temperature/atmospheric pressure to determine the amount of released gas and the gas permeation properties of PE materials using a diffusion analysis program [27]. In our study, we provided a database on the gas permeation properties of the PE materials with different densities for the five types of pure gases.…”