Magnetic chitosan/iron (II, III) oxide nanoparticles prepared by spray-drying

Chitosan/iron (II, III) oxide nanoparticles with various ratios of chitosan/iron (CS1/Fe4, CS2/Fe4 and CS3/Fe4) were prepared by a spray-drying method. Atomic absorption spectrometry (AAS). Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) spectrometry data confirm that magnetic crystalline Fe3O4 interacts with chitosan and distributes in the chitosan matrix. Field emission scanning electron microscopy (FESEM) micrographs indicate that nanoparticles so prepared have a good sphericity and a rough surface morphology. The average diameters of CS1/Fe4, CS2/Fe4, and CS3/Fe4 were 236,379 and 417 nm, respectively. Superconducting quantum interference device (SQUID) results indicate that the highest saturation magnetization of magnetic nanoparticles is about 27.91 emu/g. The hysteresis loop of the samples shows that all samples manifest zero coercivity and zero remanence, which infers that each of the samples has a superparamagnetic property. Dynamic light scattering (DLS) data show that the zeta potential of samples is higher than 45 mV, indicating that the samples can steadily distribute in water. (C) 2010 Elsevier Ltd. All rights reserved.