Discipline: Chemistry and Chemical Sciences
Subcategory: Materials Science
Victor Fernandez-Alos - University of Puerto Rico-Mayaguez
Co-Author(s): Felix R. Roman-Velazquez, Oscar J. Perales-Perez, and Arturo J. Hernandez-Maldonado, University of Puerto Rico-Mayaguez, PR
Nanotechnologies remains an area of extensive research, especially in the development of nano materials with magnetic properties with low toxicity, and environmentally friendly. Extensive applications of magnetic nanoparticles are applied to research areas such as catalytic agents, electronic devices, targeted-drug delivery, therapeutic hyperthermia treatments, magnetic resonance imaging enhancements, and environmental remediation. Different methods for synthesis of magnetite nanoparticles such as co-precipitation, sonochemical, electrochemical, micro-emulsions, and sol-gel processes, among other have been developed. However, in this research, the co-precipitation method was used to integrate chemical modifications of surfactant directly into the synthesis of magnetic nanoparticles. Properties such as particle size, surface functionalization, and magnetic characteristics before and after oxidation surface process were studied. Some changes on the diameter of the particle size, which ranged from (61nm – 83nm) and (53nm – 68nm) for the magnetite/Sodium-Oleate before oxidation, and magnetite/Sodium-Oleate after oxidation were observed. The nanoparticles sizes were studied by particle sizing systems. Attenuated transmittance reflectance-Fourier transform infrared (ATR-FTIR) was used to determine the effects of potassium permanganate oxidation agent concentrations on the oxidative cleavage of Sodium-Oleate functional group bound to the magnetite nanoparticles surface. The ATR-FTIR spectrum showed the oxidation of the carbon double bonds in Sodium-Oleate increased as a function of the oxidant agent concentrations. Furthermore, insights of magnetite modified-surface were observed from X-ray diffraction, point of zero charge, and transmission electron microscopy. The magnetic nanoparticles covered with surfactants improved its colloidal stability, agglomeration, and the relationships between size-shape. A variety of surfactants have been used to cover the magnetite; likewise, a substantial number of methods for synthesizing magnetite particles in nano-scale have been produced and/or modified in the last decades. However, the ability to modify, in one step, the functional groups on the surface of magnetic particle covered by Sodium-Oleate integrated into co-precipitation is novel and was demonstrated for the first time in this study. It is noteworthy to mention, this one-step reaction added to co-precipitation method proved to be efficient, cost effective and environmentally friendly.
Funder Acknowledgement(s): Funding was provided by the National Science Foundation under Award No. HRD-1345156 (CREST Phase 2 Program).
Faculty Advisor: Felix R. Roman-Velazquez, felixr.roman@upr.edu
Role: Although this research was designed and developed by myself, significant participations of undergraduate students from different fields of science and engineering have been contributed to my thesis projects.