Free volume impact on ionic conductivity of PVdF/GO/PVP solid polymer electrolytes via positron annihilation approach

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Küçük Resim

Tarih

2025

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Elsevier Ltd

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

This study reports the effects of free volume (FV) profiles on the ionic conductivities of PVdF/GO/PVP ternary polymer electrolytes using positron annihilation lifetime spectroscopy (PALS). The electrolytes were characterized by various tests such as FTIR, XRD, TGA-DTG, SEM, contact angle and DMA. FV profiles were evaluated by o-Ps lifetime (τ₃), intensity (I3) and FV fractions (fυ). PVdF exhibits a proton conductivity of 2.1 × 10⁻5 S/m at 80 °C. However, the introduction of GO leads to a decrease in conductivity, with PVdF/GO showing 1.7 × 10⁻5 S/m at 80 °C. The presence of PVP in PVdF/GO/PVP10 and PVdF/GO/PVP30 creates new FV spaces via hydrogen bonds and intermolecular interactions, expanding hydrophobic areas and increasing I₃ values. PVP's high mobility and positive charge density reduce the τ₃ values. In contrast, I₃ and fυ values decrease in PVdF/GO/PVP50, accompanied by a significant drop in τ₃ values and the proton conductivity and dielectric constant peak at 6.1 × 10⁻2 S/m and 77.38, respectively. High PVP concentration may enhance interactions within the polymer matrix, forming a dense structure that, despite reduced FV, maintains or enhances proton mobility through alternative conduction pathways and increased polarization. This study emphasizes the balance of FV and dielectric behavior for efficient electrochemical processes.

Açıklama

Anahtar Kelimeler

Free Volume, Graphene Oxide, Positron Annihilation, PVdF, PVP

Kaynak

Radiation Physics and Chemistry

WoS Q Değeri

Q1

Scopus Q Değeri

Q1

Cilt

Sayı

229

Künye