STABILIZATION OF IRON NANOPARTICLES BY BIOPOLYMERS DURING CHEMICAL REDUCTION WITH SODIUM BOROHYDRIDE

Abstract

Abstract. Introduction. One of the effective ways to regulate the processes of formation and agglomeration of FeNPs is the use of biopolymer stabilizers. The goal is to investigate the influence of biopolymer stabilization on the size, morphological and crystalline characteristics of FeNPs obtained by chemical reduction of NaBH4. Methods. FeNPs were synthesized by reduction of Fe3+ with NaBH4, stabilized with chitosan and sodium carboxymethylcellulose. The optical properties were studied using UV-Visible spectrophotometry, FTIR to identify functional groups, SEM-EDS and TEM to examine morphology and elemental composition, XRD to determine crystalline phases, and DLS-ELS to evaluate hydrodynamic diameter and ζ-potential. Results and discussion. UV-Vis spectra showed a characteristic 260-300 nm absorption band of iron-containing nanostructures. FTIR spectra indicated Fe-O bonds and interactions between FeNPs and biopolymer functional groups. SEM analysis showed reduced aggregation in FeNPs/Na-CMC and FeNPs/CS compared with unstabilized FeNPs. EDS analysis confirmed the presence of Fe and O elements and the formation of an oxide/hydroxide phase. XRD analysis revealed the formation of crystalline iron oxide phases. The average-sized crystallites are approximately 18 nm for FeNPs, 14 nm for FeNPs/Na-CMC, and 10 nm for FeNPs/CS. TEM and DLS/ELS confirmed the formation of spherical FeNP/CS nanoparticles with a size range of 20.03 ± 3.62 nm and a zeta-potential of -30.6 mV.Conclusion. Biopolymer stabilizers were found to reduce the growth and aggregation of FeNPs. CS effectively limits crystallite growth and suppresses agglomeration, while Na-CMC forms structurally organized composite particles. The results demonstrate the potential of using biopolymers to stabilize iron-containing nanomaterials.