Tuning of magnetic parameters in cobalt–polystyrene nanocomposites by reduction cycling

Cobalt nanoparticles were prepared by a reduction process inside polymer pores using CoSO4·7H2O and NaBH4. A porous polymer network (sulphonated polystyrene) was chosen, as the template for the synthesis of elementary cobalt as high surface area cobalt nanoparticles are prone to oxidation. The preliminary studies reveal that the cobalt is first formed with an oxide protective layer outside and upon repeating the reduction cycles, inner pores of the polymers are opened which enhanced the yield of metallic cobalt. These high surface area cobalt nanoparticles embedded in a polymer are ideal for the synthesis of carbon nanotubes as cobalt can act as a catalyst for the nanotube synthesis. The concentration of cobalt can be tuned in this technique by repeating the cycling process.

Cobalt nanoparticles were prepared by a reduction process inside polymer pores. A porous polymer network (polystyrene) was chosen as the template for the synthesis of elementary cobalt as high surface area cobalt nanoparticles are prone to oxidation. The preliminary studies reveal that the cobalt is first formed with an oxide protective layer outside and upon repeating the reduction cycles, inner pores of the polymers are opened which enhanced the yield of metallic cobalt. These high surface area cobalt nanoparticles embedded in a polymer are ideal for the synthesis of carbon nanotubes as cobalt can act as a catalyst for the nanotube synthesis. The concentration of cobalt can be tuned in this technique by repeating the cycling process.Figure optionsDownload as PowerPoint slideHighlights
► Elementary cobalt nanoparticles were synthesized inside polystyrene by a novel process.
► The self protection is achieved by the auto-shelling with the metal oxide.
► The magnetisation and coercivity could be tuned by repeating the cycles.
► Tuning of magnetic properties (both coercivity and magnetisation) could be achieved by the repetition of reduction cycles.
► Synthesized nanocomposite can act as a catalyst for carbon nanotube synthesis.