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Báo cáo vật lý: "THE EFFECT OF ADDITIVES ON THE SIZE OF Fe3O4 PARTICLES"

Tuyển tập các báo cáo nghiên cứu khoa học trên tạp chí khoa học vật lý quốc tế đề tài: THE EFFECT OF ADDITIVES ON THE SIZE OF Fe3O4 PARTICLES | Journal of Physical Science Vol. 17 2 37-50 2006 37 THE EFFECT OF ADDITIVES ON THE SIZE OF Fe3O4 PARTICLES W.L. Tan and M. Abu Bakar Nanoscience Research Laboratory School of Chemical Sciences Universiti Sains Malaysia 11800 USM Pulau Pinang Malaysia Corresponding author bmohamad@usm.my Abstract The study on the effect of different additives on the size and size uniformity of magnetite Fe3O4 nanoparticles is described. The magnetite particles are characterized by Fourier Transform Infrared FTIR and X-ray diffraction XRD . The X-ray powder diffraction patterns and IR spectra of the as-formed magnetite particles indicate additive-free products were obtained. Analyses on the size and size distribution of the magnetite obtained suggest that the additives - surfactants chitosan and inorganic ligands have different manipulating ability. Surfactants gave better manipulation on particle size ca. 45 nm as well as the size distribution ca. SD 20 nm . Chitosan can manipulate the size distribution while maintaining the average size of the original magnetite. Whereas inorganic ligands with the exception of thiourea exert only slight influence on the size distribution with no manipulation over the average size. Transmission electron microscopy TEM micrographs suggest that citrate and stearic acid may have affected the final morphology of the magnetite formed in their presence. Keywords magnetite particles size surfactants chitosan nanoparticles 1. INTRODUCTION Ferromagnetic oxides mostly magnetite Fe3O4 and maghemite Y-Fe2O3 form an interesting class of nanomaterials. They have been extensively studied recently due to their unique physical chemical thermal and mechanical properties 1 . Iron oxides are used in broad range of applications including biomedical 1 2 adsorbent 3 catalysis 4 5 magnetic storage devices 6 magnetic refrigeration systems 7 and passivation coatings 8 among others. Magnetite is a common magnetic iron ore comprise of 72.36 iron and 27.64 oxygen exhibits high