Impact of halide anions on ionic transport and thermoelectric properties of polyvinyl alcohol-based eutectogel
Journal
Materials Today Energy
Journal Volume
54
Start Page
102105
ISSN
24686069
Date Issued
2025-12
Author(s)
Jheng, Yu-Syuan
Hsu, Ching‐Chieh
Hong, Shao-Huan
Hsu, Chi-Wei
Kuo, Shiao-Wei
Wang, Chia-Hsin
Jeng, U-Ser
Abstract
An environmentally friendly eutectogel (ETG) based on polyvinyl alcohol (PVA) and glycerol-based deep eutectic solvents (DESs) is developed without chemical crosslinkers. Unlike most previous studies that exclusively employed choline chloride (ChCl) as the hydrogen bond acceptor (HBA), this work systematically investigates three different HBAs, namely choline chloride (ChCl), choline bromide (ChBr), and choline iodide (ChI), whose anions possess distinct chaotropic properties. Among them, I−, exhibiting the strongest chaotropic effect, disrupts the hydrogen-bonding network and lowers the crystallinity of the PVA matrix. The thermoelectric properties are mainly determined by DES viscosity, ion-polymer binding energy, and steric effects from ionic size. Of the three, the Br−-based ETG achieves the highest ionic conductivity (63.33 mS cm−1), thermopower (5.70 mV K−1), and ionic figure of merit (0.14), owing to its optimal balance of moderate halide-polymer interactions, low viscosity, and small ionic radius. This comparative study expands the scope of HBAs beyond conventional ChCl, providing new design principles and broader material choices for thermoelectric gels in sustainable and wearable energy-harvesting.
Subjects
Biocompatible
Eutectogel
Hydrogen bond acceptor
Thermoelectric
Wearable device
SDGs
Publisher
Elsevier Ltd
Type
journal article