Magnetic and optical properties of poly(vinylidene difluoride)/Fe 3 O 4 nanocomposite prepared by coprecipitation approach

Poly(vinylidene difluoride) (PVDF)/Fe 3 O 4 magnetic nanocomposite was prepared by a simple coprecipitation method, and was characterized by scanning electron microscope (SEM), X‐ray diffraction (XRD), vibrating sample magnetometer (VSM), and ultraviolet visible spectroscopy (UV‐Vis). The SEM images showed that Fe 3 O 4 nanoparticles were dispersed in the PVDF matrix as some aggregates with the sizes of 50 nm–2 μm, and the XRD curves showed the incorporation of the Fe 3 O 4 nanoparticles in PVDF matrices and the decrease of the crystallinity of the PVDF. VSM results showed that the saturation magnetization ( M s ) and remnant magnetization ( M r ) of the PVDF/Fe 3 O 4 nanocomposite increased with the increase of the Fe 3 O 4 content, and that M s and M r along the parallel direction were higher than those along the perpendicular direction at the same Fe 3 O 4 content. The coercive force ( H c ) of the nanocomposite was independent of the Fe 3 O 4 content and approximately equal along the parallel and perpendicular direction at the same Fe 3 O 4 content. The optical band gap ( E g ) of the PVDF/Fe 3 O 4 nanocomposite was influenced by the Fe 3 O 4 content, and decreased by 0.75 eV compared with that of pure PVDF when the Fe 3 O 4 content was 3 wt %. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009