Synthesis and characterization of poly(vinyl phosphonic acid) (PVPA)-Fe3O4 nanocomposite

► PVPA coated Fe3O4 nanoparticles have been prepared by the in situ polymerization of PVPA for the first time. ► As a nanocomposite, its dielectric, magnetic, structural and morphological properties were investigated in detail for the first time. ► Organic/inorganic nanocomposite membranes consisting of Fe3O4/PVPA (polyvinyphosphonic acid) hybrids showed a maximum ionic conductivity of 1.0 × 10−7 S/cm at 120 °C. ► Although this low conductivity precludes its use, it still has wide technological applications, particularly in biotechnology.