This study describes a preparation of magnetite nanoparticle by co-precipitation of Fe(II) and Fe(III) in alginate hydrogel matrix. This simple process is sufficient for producing a superparamagnetic, well dispersible magnetite nanoparticle in polymer hydrogel matrix. Two approaches for iron ions loadings are induced. | Vietnam Journal of Science and Technology 56 (1A) (2018) 167-173 PREPARATION OF MAGNETIC HYDROGEL BY IN-SITU COPRECIPITATION PROCESS Ngoc Uyen Nguyen-Thai1, *, Chi Nhan Ha Thuc1, Thi Vi Vi Do1, Nang An Vu1, Tien Trung Vu1, Thi Ngoc Mai Tran2 1 Faculty of Materials Science and Technology, University of Science-VNU-HCM City, 227 Nguyen Van Cu, District 5, Ho Chi Minh City 2 Bio-Food Technology and Environment Department, Hutech University of Technology, 475A Dien Bien Phu, Binh Thanh District, Ho Chi Minh City * Email: ntnuyen@ Received: 15 August 2017; Accepted for publication: 25 February 2018 ABSTRACT This study describes a preparation of magnetite nanoparticle by co-precipitation of Fe(II) and Fe(III) in alginate hydrogel matrix. This simple process is sufficient for producing a superparamagnetic, well dispersible magnetite nanoparticle in polymer hydrogel matrix. Two approaches for iron ions loadings are induced. The first approach includes two steps, the hydrogel beads are formed before the iron ions are being diffused into the hydrogel matrix. The second approach is the simultaneous forming of hydrogel containing iron ions. The ions loaded hydrogel is then coprecipitated in the presence of ammonium hydroxide to afford iron oxide magnetite nanoparticles in alginate hydrogel matrix. The composition and characteristics of the hydrogel containing magnetite nanoparticle were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM). The results showed that the particles size of magnetic nanoparticles prepared by in-situ coprecipitation method is around ~ 6 nm and smaller than that produced by normal coprecipitation method. The magnetic hydrogel exhibits superparamagnetic properties with the saturation magnetization of about 25 emu/g, the ratio of Mr/Ms about ×10-3. Possessing the biocompatibility as well as superparamagnetism, the .
