Sunaryono, Ahmad Taufiq, Edy Giri Rahman Putra, Atsushi Okazawa, Isao Watanabe, Norimichi Kojima, Supagorn Rugmai, Siriwat Soontaranon, Mohammad Zainuri, Triwikantoro, Suminar Pratapa, Darminto
A synchrotron small-angle X-ray scattering (SAXS) study on PVA/Fe3O4 magnetic hydrogels has been performed to investigate the effect of clustering on their magnetic properties. The hydrogels were prepared through freezing-thawing (F-T) processes. The structure, morphology and magnetic properties of magnetite (Fe34) nanoparticles (NPs) were investigated using X-ray diffractometry (XRD), transmission electron microscopy (TEM) and a superconducting quantum interference device (SQUID) magnetometer, respectively. In this study, SAXS data were used to reveal the structural dimensions of the magnetite and its distribution in the polymer-rich PVA and magnetic hydrogels. As calculated using the Beaucage and Teubner-Strey models, the average of the structural dimensions of the PVA hydrogels was 3.9nm (crystallites), while the average distance between crystallites was approximately 18nm. Further analysis by applying a two-lognormal distribution showed that the magnetite NPs comprised secondary particles with a diameter of 9.6nm that were structured by primary particles (∼3.2nm). A two-lognormal distribution function has also been used in describing the size distributions of magnetite NPs in magnetic hydrogels. The clusters of magnetite NPs in the magnetic hydrogels are significantly reduced from 30.4nm to 12.8nm with decreasing concentration of the NPs magnetite from 15wt.% to 1wt.%. The saturation magnetization values of the magnetite NPs, the 15% and 1% magnetic hydrogels were 34.67emu/g, 6.52emu/g and 0.37emu/g, respectively. © 2016 World Scientific Publishing Company.
Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Sepuluh Nopember, Kampus ITS Sukolilo, Surabaya, 60111, Indonesia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Malang, 65145, Indonesia; Center for Science and Technology of Advanced Materials, National Nuclear Energy Agency of Indonesia, Kawasan Puspiptek Serpong, Tangerang, 15134, Indonesia; Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan; Advanced Meson Laboratory, Nishina Accelerator Based Science Center, RIKEN, 2-1 Hirosawa, Saitama, Wako-shi, 351-0198, Japan; Toyota Physical and Chemical Research Institute, Yokomichi 41-1, Nagakute, Aichi, 480-1192, Japan; Synchrotron Light Research Institute, 111 University Venue, Muang District, Nakhon Ratchasima, 30000, Thailand
