Effect of molecular weight of sodium polyacrylates on the size and morphology of nickel nanoparticles synthesized by the modified polyol method and their magnetic properties

Logutenko, O. A.; Titkov, A. I.; Vorob'yov, A. M.; Balaev, D. A.; Shaikhutdinov, K. A.; Semenov, S. V.; Yukhin, Y. M.; Lyakhov, N. Z. EUROPEAN POLYMER JOURNAL, 99 102-110; 10.1016/j.eurpolymj.2017.12.017 FEB 2018

Nickel nanoparticles were synthesized by the reduction of nickel chloride with hydrazine hydrate in a polyol medium in the presence of sodium polyacrylates (Na-PA) having molecular weights (Mw) of 1200, 5100 and 8000. The size and morphology of the resulting nickel nanoparticles were characterized by X-ray diffraction, scanning and transmission electron microscopy. Polymers having lower Mw values were found to be more efficient in reducing the nickel particle size. A decrease in the polymer concentrations yielded the smaller particles. Magnetic measurements showed that the as-prepared powders are ferromagnetic and their saturation magnetization and coercivity are size-dependent. Compared with bulk nickel, the nanoparticles exhibit an enhanced coercivity which is due to their small size and a decreased saturation magnetization resulted from the surface oxidation of the powder. The synthesis procedure offers a simple approach to preparing nickel nanopowders on a large scale which could be used as magnetic recording materials, including high-density memory storage devices.