title: Effect of nitric acid concentrations on synthesis and stability of maghemite nanoparticles suspension.
abstract: Maghemite (γ-Fe2O3) nanoparticles have been synthesized using a chemical coprecipitation method at different nitric acid concentrations as an oxidizing agent. Characterization of all samples performed by several techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), alternating gradient magnetometry (AGM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and zeta potential. The XRD patterns confirmed that the particles were maghemite. The crystallite size of all samples decreases with the increasing concentration of nitric acid. TEM observation showed that the particles have spherical morphology with narrow particle size distribution. The particles showed superparamagnetic behavior with decreased magnetization values at the increasing concentration of nitric acid. TGA measurement showed that the stability temperature decreases with the increasing concentration of nitric acid. DLS measurement showed that the hydrodynamic particle sizes decrease with the increasing concentration of nitric acid. Zeta potential values show a decrease with the increasing concentration of nitric acid. The increasing concentration of nitric acid in synthesis of maghemite nanoparticles produced smaller size particles, lower magnetization, better thermal stability, and more stable maghemite nanoparticles suspension.
authors: Nanomaterials Engineering Research Group, Advanced Materials Research Laboratory, Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Department of Chemical Engineering, Lhokseumawe State Polytechnic, Lhokseumawe 24301, Indonesia.
authors: Irwan
authors: 0000-0002-1547-4810
authors: I
authors: Nurdin
authors: Nanomaterials Engineering Research Group, Advanced Materials Research Laboratory, Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors: Mohd Rafie
authors: 0000-0003-1133-9977
authors: MR
authors: Johan
authors: Department of Manufacturing and Materials Engineering, Kulliyyah of Engineering, International Islamic University Malaysia, 50728 Kuala Lumpur, Malaysia.
authors: Iskandar Idris
authors: II
authors: Yaacob
authors: Nanomaterials Engineering Research Group, Advanced Materials Research Laboratory, Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors: Bee Chin
authors: 0000-0001-8690-4104
authors: BC
authors: Ang
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D017942:Nitric Acid / Q000737:chemistry*; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide; D017942:Nitric Acid