| Title |
Measurement of Gas Transport Properties for H2, He and N2 in Gas Enriched-LDPE, HDPE and NBR Polymers with Volumetric Semi-Cylindrical and Coaxial-Cylindrical Capacitive Electrodes Sensors |
| Authors |
김경현(Gyung Hyun Kim); 문영일(Young Il Moon); 정재갑(Jae Kap Jung) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.7.515 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Diffusivity; Polymer; Solubility; Gas permeation; Gas sensor; Capacitive electrode |
| Abstract |
In this study, a high-performance gas sensing system is developed by integrating capacitive electrode-based sensing with volumetric analysis to quantitatively evaluate gas uptake and diffusivity from gas-enriched polymer specimens. The sensor system comprises two types of capacitive electrode configurations: (1) a dual semi-cylindrical electrode pair affixed to the outer surface of a graduated cylinder and (2) a coaxial-cylindrical electrode consisting of a central thin copper rod and a transparent conductive film attached to the outer wall of the cylinder. Gas emitted from the polymer displaces water inside the graduated cylinder, altering the dielectric constant and resulting in measurable capacitance changes. This enables simultaneous detection of the volume and concentration of emitted gas under high-pressure conditions. The sensor exhibits a rapid response (~1 s) and a wide detection range (0.5 to 1000 wt·ppm), with tunable sensitivity and resolution depending on the electrode geometry, specimen number, and cylinder inner volume. Performance tests showed good agreement with conventional methods, confirming the accuracy and reliability of the system. The sensing platform was applied to polymers commonly used in high-pressure gas sealing―nitrile butadiene rubber (NBR), low-density polyethylene (LDPE), and high-density polyethylene (HDPE)―to evaluate gas transport properties under various pressures. Its applicability to pure gases such as hydrogen, helium, and nitrogen also was verified. This capacitive-volumetric hybrid technique offers a scalable and precise tool for real-time gas permeability analysis in both research and industrial environments.(Received 24 April, 2025; Accepted 5 June, 2025) |