Preparation of metal-polymer composites through the thermolysis of Fe(II), Co(II), and Ni(II) maleates

Metal-polymer composites have been prepared through the thermolysis of the [M1(H2O)2(C4H2O4)] · H2O (M1 = Co(II), Ni(II)) neutral maleates and [M2(H2O)4(C4H3O4)2] (M2 = Fe(II), Co(II), Ni(II)) acid maleates. In the polymer matrix of the Fe-containing composite, we identified metal, Fe2O3, and Fe3O4 particles, with slight densification of the matrix around them. The polymer matrix of the cobalt maleate-derived composite contained four types of nanoparticles: α-Co, β-Co, and CoO in polymer shells and Co3O4 with no polymer shell. The decomposition of the nickel maleates yielded homogeneous nickel nanoparticles (4–5 nm) covered with two to five graphene layers. The Co-containing composite was found to be a dielectric. The Ni-containing composite exhibited variable range hopping conduction in the range T ≤ 50 K.