Boosting Dielectric Properties of Polyethersulfone Membranes: A Strategy Using Cross-Linked Graphene Oxide/EDTA/Silane

We investigated development and characterization of composite membranes based on grafted graphene oxide (GO) with ethylenediamine tetraacetic acid (EDTA)/silane loaded onto polyethersulfone (PES) for dielectric applications. Fourier transform infrared analysis confirmed the presence of oxygen-containing groups on GO and the introduction of new peaks corresponding to EDTA/silane in the composite membrane. X-ray diffraction revealed a shift in diffraction peaks, indicating successful GO modification. Raman spectroscopy showed an increase in the defect ratio (ID/IG) after modification, suggesting an interaction between EDTA/silane and GO. Transmission electron microscopy is expected to show morphological changes in GO upon incorporation of EDTA/silane. Scanning electron microscopy of the PES membranes revealed a change in surface morphology from smooth to small pores with a non-smooth surface upon the addition of GO/EDTA/silane. UV–vis spectroscopy indicated a red shift in the absorption peak of GO/EDTA/silane compared to GO, suggesting a decrease in oxygenated groups. Dielectric properties measurements demonstrated enhanced dielectric permittivity and improved polarization response for PES membranes containing GO/EDTA/silane compared to the pristine PES membrane. The dielectric constant of PES at 1 kHz is 2.42 and increased gradually to 4.82 for the 15% GO/EDTA/Silane-doped composition. This improvement is attributed to the conductive network, high surface area, and functional groups of GO within the membrane.