One-step synthesis, characterization and properties of novel hybrid electromagnetic nanomaterials based on polydiphenylamine and Co-Fe particles in the absence and presence of single-walled carbon nanotubes

A one-step preparation method for hybrid electromagnetic nanomaterials based on polydiphenylamine (PDPA) and bimetallic Co-Fe particles in the absence and presence of single-walled carbon nanotubes (SWCNT) was proposed. During IR heating of PDPA in the presence of Co( ii ) and Fe( iii ) salts in an inert atmosphere at T = 450-600 °C, the polycondensation of diphenylamine (DPA) oligomers and dehydrogenation of phenyleneamine units of the polymer with the formation of C&z.dbd;N bonds and reduction of metals by evolved hydrogen with the formation of bimetallic Co-Fe particles dispersed in a polymer matrix occur simultaneously. When carbon nanotubes are introduced into the reaction system, a nanocomposite material is formed, in which bimetallic Co-Fe particles immobilized on SWCNT are distributed in the matrix of the polymer. According to XRD data, reflection peaks of bimetallic Co-Fe particles at diffraction scattering angles 2 = 69.04° and 106.5° correspond to a solid solution based on the fcc-Co crystal lattice. According to SEM and TEM data, a mixture of particles with sizes of 8-30 nm and 400-800 nm (Co-Fe/PDPA) and 23-50 nm and 400-1100 nm (Co-Fe/SWCNT/PDPA) is formed in the nanocomposites. The obtained multifunctional Co-Fe/PDPA and Co-Fe/SWCNT/PDPA nanomaterials demonstrate good thermal, electrical and magnetic properties. The saturation magnetization of the nanomaterials is M S = 14.99-31.32 emu g −1 (Co-Fe/PDPA) and M S = 29.48-48.84 emu g −1 (Co-Fe/SWCNT/PDPA). The electrical conductivity of the nanomaterials reaches 3.5 × 10 −3 S cm −1 (Co-Fe/PDPA) and 1.3 S cm −1 (Co-Fe/SWCNT/PDPA). In an inert medium, at 1000 °C the residue is 71-77%. In a self-organizing system within one stage under IR heating conditions, hybrid nanomaterials are formed with a structure that contains bimetallic Co-Fe particles, free or immobilized on the SWCNT surface, dispersed in the polymer PDPA matrix.