Colloidal stability improvement of cobalt ferrite encapsulated in carboxymethylated cashew gum

Author(s):Show less -

Abreu, Maria K. S. O. ; Silva, Maria A. S. ; Abreu, Dieric S. ; Richter, Ana R. ; de Paula, Regina C. M. ; Constantino, Vera R. L. ; Vasconcelos, Igor F. ; de Oliveira, Francisco G. S. ; de Melo, Acacio S. ; Correa, Marcio A. ; Diogenes, Izaura C. N.

• Document type: Journal article
• Source: COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS; v. 656, p. 8-pg., 2023-01-05.

Abstract

Colloidal stability in water media is a critical issue for several applications of magnetic nanoparticles (MNPs). In this work, we discuss the colloidal stability improvement of CoFe2O4 after encapsulation in carboxymethylated cashew gum (CMCG), which is a natural, biocompatible, and low-cost modified polymer. Microscopic and vibrational analyses of the obtained material CoFe2O4@CTAB@CMCG, indicated a sort of polymer-caged MNPs aggregate (mean diameter of 78 nm) in which the magnetic core is surrounded by the CTAB (hexadecyl-trimethylammonium bromide) surfactant whose polar tails interact with CMCG resulting in a negatively charged layer. Such arrangement explains the colloidal stability increment as deduced from zeta potential values of -34 mV (in water) and -14 mV (in PBS) for CoFe2O4@CTAB@CMCG in respect to CoFe2O4@CTAB (+30 mV in water). Despite the dilution effect imparted by the non-magnetic mass of CMCG, a saturation magnetization of 70.16 emu g-1 was determined for CoFe2O4@CTAB@CMCG meaning the material maintains the magnetization after encapsulation. Our work, therefore, not only introduces a low-cost strategy in line with the awareness about environmental issues but also adds value to the cashew gum which is a typical and abundant product from the northeast region of Brazil. (AU)

• FAPESP's process: 19/21939-0 - Bimetallic anisotropic nanoparticles (Au/Pd) for the study of catalytic processes through surface enhanced Raman scattering
• Grantee: Dieric dos Santos de Abreu
• Support Opportunities: Scholarships in Brazil - Post-Doctoral