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