Author(s):
dos Santos, Caio C. [UNESP] ; Viali, W. R. [UNESP] ; Viali, E. S.N. ; Marques, R. F.C. [UNESP] ; Jafelicci Junior, M. [UNESP]
Date: 2020
Persistent ID: http://hdl.handle.net/11449/200806
Origin: Oasisbr
Subject(s): Complex fluids; Coprecipitation; Magnetic nanoparticles; Magnetite; Oxide nanoparticles; Two-step nanofluid; Complex fluids; Complex fluids; Coprecipitation; Coprecipitation; Magnetic nanoparticles; Magnetic nanoparticles; Magnetite; Magnetite; Oxide nanoparticles; Oxide nanoparticles; Two-step nanofluid; Two-step nanofluid
Description
Made available in DSpace on 2020-12-12T02:16:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01
In this work, we report the synthesis of a new nanofluid (NF) based on magnetic nanoparticles (MNPS) synthesized by the coprecipitation method with high colloidal stability. The MNPS were functionalized with citric acid (Cac), and then, polyethylene glycol, 1000 (PEG1000), was bonded by polycondensation reactions with acid groups on the nanoparticles surface to increase the colloidal stability of the nanofluid. The MNPS were dispersed in an aqueous medium to obtain nanofluid-based magnetic nanoparticles in water (NF-MNPS-W) and in ethylene glycol to obtain nanofluid-based magnetic nanoparticles in ethylene glycol (NF-MNPS-E). The MNPS were characterized by X-ray diffraction and selected area electron diffraction, which confirmed the formation of the crystalline phase of Fe3O4. Transmission electron microscopy was used to confirm the size and morphology of the MNPS. The MNPS had an average diameter of 11.33 ± 3.68 nm. Infrared spectrum of the MNPS allowed the functionalization of the MNPS by Cac and then by PEG1000 to be proved. The colloidal stability of NF-MNPS-W (pH 8) and NF-MNPS-E was evaluated by measurement of Zeta potential (ζ) and dynamic light scattering (DLS) − 25 mV and 112 nm ± 1 nm, respectively. The DLS in the temperature function allowed the stability of the NF to be proved in working conditions.
Laboratory of Magnetic Materials and Colloids Department of Physical Chemistry Institute of Chemistry São Paulo State University (UNESP)
Goiano Federal Institute of Education Science and Technology, Rodovia Sul Goiana Km 01, Zona Rural
Laboratory of Magnetic Materials and Colloids Department of Physical Chemistry Institute of Chemistry São Paulo State University (UNESP)
