Advantages incorporating V2O5 nanoparticles into PMMA composite membranes for the structural, optical, electrical, and mechanical properties for conductive polymeric membrane applications

Abstract

Poly(methylmethacrylate) (PMMA) and PMMA membranes with incorporated vanadium pentoxide (V₂O₅) nanoparticles were prepared using the solution-casting method with different ratios of dopant (V₂O₅:0, 0.1, 0.5, 1.0, and 3.0 wt%). The structure of the membranes was investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infra-red spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The diffraction pattern of the pure PMMA membrane demonstrates an amorphous structure, while V₂O₅ demonstrates an orthorhombic structure. The thermal stability of the blank PMMA is improved as the amount of V₂O₅ increases. Optical parameters, including the refractive index and optical bandgap energy, were calculated, and it was confirmed that with the addition of V₂O₅, the bandgap value changed from 4.88 eV (direct transition) to 1.32 eV (indirect transition) for the blank PMMA and 3% V₂O₅/PMMA, respectively. Measurement of the dielectric behavior shows that V₂O₅-doping of the PMMA increased the dielectric constant, dielectric loss, and impedance. Furthermore, the electrical conductivity is enhanced with the addition of V₂O₅. Moreover, the dynamic mechanical properties were investigated, and the storage modulus E′ has a relatively high value (∼1.6 GPa) at room temperature (∼300 K). As the temperature increases, E′ decreases drastically to 12.5% of its value at room temperature at 80 °C.