Research Information System
Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol.727, 2025 (SCI-Expanded, Scopus)
In this work, chitosan (CS)-based composite polymer electrolytes were developed by incorporating n-butylimidazolium tetrafluoroborate ionic liquid (ButIm-BF4, IL) and sulfonated silica (sSiO2) to achieve efficient anhydrous proton conduction. Composite membranes were prepared via solution casting method and characterized by FTIR, XRD, SEM, and TGA for structural, morphological and thermal evaluations. Proton conductivity tests in the 300–430 K and 20 Hz-1 MHz ranges revealed that the CS-IL-S(7.5) membrane, containing 7.5 wt% sSiO2, exhibited the highest proton conductivity (σ) (1.2 mS/cm) corresponding to ∼330-fold higher than neat CS (3.65 ×10⁻3 mS/cm) and ∼6.5-fold higher than CS-IL (1.84 ×10⁻1 mS/cm). Dielectric analyses demonstrated a maximum dielectric constant (ε′) of 2.19 × 106 at 20 Hz and 300 K for CS-IL-S(7.5). A loss tangent (tanδ) of ∼7.6 with an ultrafast relaxation time (τ) of 3.98 × 10⁻7 s confirmed high ionic mobility with minimal polarization losses. Structural and morphological studies indicated amorphous character and interconnected conduction pathways, while thermal analysis showed maintained stability. These results highlight CS/IL/sSiO2 membranes as eco-friendly and cost-effective candidates for electrochemical energy storage devices operating under anhydrous and high-temperature conditions.