摘要
Nano-composites comprised of magnetite nanoparticles in a pectin matrix were prepared by the co-precipitation method. Both sodium hydroxide and ammonium hydroxide were used as precipitating agents and the effects of stoichiometric ratios of iron salts to polymer concentration on particle properties were investigated. The precipitates obtained with NH4OH were sponge-like. The XRD pattern revealed magnetite as the only iron oxide phase present when NH4OH was used as precipitating base whilst nanoparticles precipitated using NaOH showed the presence of additional peaks. The nanocomposites obtained were further characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and zeta-potential. FT-IR confirmed the COO-Fe linkage. Zeta-potential analysis showed a potential change from positive in pure magnetite to negative in polymer coated magnetite depending on the oxide-polymer ratio. SEM and TEM showed fairly evenly distributed nanosize pores.
Nano-composites comprised of magnetite nanoparticles in a pectin matrix were prepared by the co-precipitation method. Both sodium hydroxide and ammonium hydroxide were used as precipitating agents and the effects of stoichiometric ratios of iron salts to polymer concentration on particle properties were investigated. The precipitates obtained with NH4OH were sponge-like. The XRD pattern revealed magnetite as the only iron oxide phase present when NH4OH was used as precipitating base whilst nanoparticles precipitated using NaOH showed the presence of additional peaks. The nanocomposites obtained were further characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and zeta-potential. FT-IR confirmed the COO-Fe linkage. Zeta-potential analysis showed a potential change from positive in pure magnetite to negative in polymer coated magnetite depending on the oxide-polymer ratio. SEM and TEM showed fairly evenly distributed nanosize pores.