Effects of source correction on positron annihilation lifetime spectroscopic analysis of graft-type polymer electrolyte membranes - Research Article

Sep 17, 2026

Source correction effects are examined for positron annihilation lifetime spectroscopy (PALS) applied to graft-type polymer electrolyte membranes (ETFE-PEMs). ETFE-PEM was prepared via radiation-induced graft polymerization followed by sulfonation, and free-volume hole parameters were measured with and without source correction for a grafting degree of 106%. After correction, r3 increases in lamellar amorphous regions, PSSA grafts, and intra-lamella interfaces, while r4 increases in mobile amorphous layers and PSSA outside lamellae. FWHM of r3 becomes much larger than that of r4 due to rearrangement in mobile amorphous regions and polystyrene layers. Source correction significantly alters r3 distribution curves, highlighting its importance for reliable o-Ps lifetime determination.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Abstract

Introduction

Proton exchange membrane fuel cells and alternative membranes

Principles of positron annihilation lifetime spectroscopy

Materials and Methods

Results

Changes in r3 and r4 after source correction

FWHM comparison of r3 and r4

Conclusion

Science & Technology Development Journal2023, 26(4):3060-3068 Open Access Full Text Article Research Article Effects of source correction on positron annihilation lifetime spectroscopic analysis of graft-type polymer electrolyte membranes Nguyen Huynh My Tue1,2, Tran Hoang Long1,2, Dinh Tran Trong Hieu1,2, Lam Hoang Hao1,2, Vo Thi Kim Yen1,2, Nguyen Manh Tuan1,2, Huynh Truc Phuong2,3, Le Quang Luan4, Pham ThiThu Hong5, Tran Van Man2,6, Tran Duy Tap1,2,* 1Faculty ofMaterials Science and Technology, University ofScience, Ho Chi Minh City, 227 Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam 2Vietnam National University, Ho Chi Minh City, Vietnam 3Faculty of Physics and Engineering Physics, University ofScience, Ho Chi Minh City, 227 Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam 4Biotechnology Center ofHo Chi Minh City, Ho Chi Minh City, Vietnam 5Research and Development Centerfor Radiation Technology (VINAGAMMA), Ho Chi Minh City, Vietnam 6Applied Physical Chemistry Laboratory, University ofScience, Ho Chi Minh City, 227 Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam Correspondence Tran Duy Tap, Faculty of Materials Science and Technology, University of Science, Ho Chi Minh City, 227 Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam Vietnam National University, Ho Chi Minh City, Vietnam Email: [tdtap@hcmus.edu.vn](tdtap@hcmus.edu.vn) History • Received: 2023-03-05 • Accepted: 2023-11-20 • Published Online: 2023-12-31 DOI : [https://doi.org/10.32508/stdj.v26i4.4052](https://doi.org/10.32508/stdj.v26i4.4052) Copyright © VNUHCM Press. This is an openaccess article distributed under the terms of the Creative Commons Attribution 4 .0 International license. ABSTRACT Introduction: Recently, the free-volume hole features of poly(styrene sulfonic acid) (PSSA) -grafted poly(ethylene-co-tetrafluoroethylene) polymer electrolyte membranes (ETFE-PEMs) have been studied using positron annihilation lifetime spectroscopy (PALS) to determine the relationship between gas crossover through a PEM and a fuel cell. As one such series, this work investigates the source correction in PAL spectroscopic analysis for ETFE-PEM. Method: ETFE-PEM was prepared by radiation-induced graft polymerization and subsequent sulfonation. The free-volume hole characteristics of ETFE-PEM with a grafting degree (GD) of 106% were determined using PALS with and without source correction. Results: After source correction, the original-ETFE and ETFE-PEM strains exhibited increases in r3 (smaller radius of free-volume holes in the lamellar amorphous regions, the PSSA grafts, and the interface zones inside the lamellae) and r 4 (larger radius of free-volume holes in the mobile amorphous layers and the PSSA grafts outside of the lamellae) . In addition, the full width at half maximum (FWHM) of r3 is much greater thanthat of r4 duetothe rearrangement in the mobile amorphous region and the polystyrene layers outside the lamellar structure. Conclusion: Source correction causes a significant change in the distribution curves of r 3 for the original-ETFE and ETFE-PEM. Thus, source correction of positron annihilation lifetime spectroscopic analyses is an important issue for determining the o-Ps lifetime of polymers, which is near the lifetime of positronsin source materials. Key words: Positron annihilation lifetime spectroscopy, ortho-positronium, free-volume hole, polymer electrolyte membrane, fuel cell INTRODUCTION Proton exchange membrane fuel cells (PEMFCs) have received much attention for novel power generation because these devices result in no emission of environmental pollutants, high energy generation efficiency, low operating temperature, and quick operation 1 . PEMFCs can be applied in transportation, mobile communication equipment, charging stations, etc. 2 . Nafion is one of the most common commercial membranes used for PEMs 3–5 . However, its limitations, such as high cost and low performance at high tem

FAQs

What problem does the paper address in PALS analysis of ETFE-PEM?

It investigates how source correction changes the PALS spectroscopic analysis used to characterize free-volume hole features in graft-type ETFE-PEMs.

How were the ETFE-PEMs prepared for the study?

ETFE-PEM was produced by radiation-induced graft polymerization, followed by sulfonation.

What are the main effects of source correction on r3 and r4?

After source correction, r3 increases in lamellar amorphous regions, PSSA grafts, and intra-lamella interface zones, while r4 increases in mobile amorphous layers and PSSA outside the lamellae.

Sep 17, 2026

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