Fabrication and characterization of PVDF/PMMA nanocomposite membranes doped with graphene oxide (GO) for separation of CO2/CH4 from flue gas

This work focuses on developing polyvinylidene fluoride/polymethyl methacrylate (PVDF/PMMA) polymer blend nanocomposites incorporating varying concentrations of graphene oxide (GO) nanoparticles fabricated via casting solution processes. XRD and FT-IR confirmed GO-induced structural modifications in PVDF/PMMA blend. The addition of GO into PMMA/PVDF blend decreased and weakened the intensity of XRD peaks, suggesting that adding GO gradually reduces the crystallinity of the films. FT-IR verified miscibility and complex formation between the pristine polymer blend and the GO-filled nanocomposite. The incorporation of GO caused shifts in the optical absorption edge to lower wavelengths, causing a decrease in the optical bandgap energy (E_g). The real and imaginary parts of the dielectric permittivity (ε′ and ε′′), electric modulus (M′, M″), and AC conductivity (σ_ac) have been measured from 0.1 Hz to 6 MHz. Both ε′ and ε′′ declined with rising frequency. The addition of different concentrations of GO generated charge transfer complexes in the polymer nanocomposites. SEM images show good homogeny with random dispersion of GO inside the polymer blend. The thermoluminescence (TL) glow curves for the nanocomposite samples irradiated 0.5, 1.0, 1.5, and 2 Gy doses show peak cantered at 207 °C. The peak position remained unchanged with increasing irradiation dosage. The dose-dependent linear growth in maximum peak height indicates radiation detection and monitoring capability.