Study on the influence factors of particle size distribution and stability of Fe3O4 magnetic nanoparticles
Chang-Shu Tsaia,b* Wei-Chun Hsua Kuo-Feng Taic
Abstract
Fe3O4 magnetic nanoparticles (MN) were prepared by using chemical co-precipitation method and were coated with reduced dextran which can modify MN with biocompatibility and stability. Furthermore, to ensure desirable qualities, all MN compounds obtained in this study were examined by superconducting quantum interference device, X-ray diffraction, fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscope and energy-dispersive X-Ray Spectroscopy. We found that Fe3O4 MN with high purity could be obtained with the following reaction condition: 90°C ± 5°C; pH value of 10-12; 2 hours reaction time. On the other hand, one-step and two-step synthesis pathways were used
to coat Fe3O4 MN with reduced dextran with the reaction temperature of 80°C ± 5°C and 2 hours reaction time. The data of size distribution of MN shows its characteristics and stabilities can be maintained for 2 days at 4°C, 22°C, 37°C, 43°C and 47°C, respectively. The average size of such MN is ca. 123.5 ± 25.56 nm; The dextran@MN derived from one-step synthesis pathway is able to hold stabilities and non-agglomeration for 7 days at 4°C, 22°C, 37°C, 43°C and 47°C, respectively. The average size of the above dextran@MN is ca. 135.3 ± 25.06 nm; Although the dextran@MN by two-step synthesis pathway retained stabilities and good characteristics for 5 days at 4°C, 22°C and 37°C, respectively, it started to aggregate at the third day post synthesis and the sizes grown to over 210 nm at the seventh day. The average size of such dextran@MN by two-step method is ca. 135.3 ± 25.06 nm.
Key words: magnetic nanoparticles、dextran、particle size distribution、stability
