Sustainable Nanomagnetism: Investigating the Influence of Green Synthesis and pH on Iron Oxide Nanoparticles for Enhanced Biomedical Applications

Abstract

This study comprehensively analyzed green nanomagnetic iron oxide particles (GNMIOPs) synthesized using a green method, investigating their size, shape, crystallinity, aggregation, phase portions, stability, and magnetism. The influence of pH and washing solvents on the magnetic properties of the nanoparticles and their incorporation into PCL membranes was examined for biomedical applications. Polyphenols were utilized at different pH values (1.2, 7.5, and 12.5), with washing being performed using either ethanol or water. Characterization techniques, including XRD, SEM, TEM, FTIR, and VSM, were employed, along with evaluations of stability, magnetic properties, and antioxidant activity. The findings indicate that both pH levels and the washing process exert a substantial influence on several properties of NMIOPs. The particle sizes ranged from 6.6 to 23.5 nm, with the smallest size being observed for GNMIOPs prepared at pH 12.5. Higher pH values led to increased crystallinity, cubic Fe3O4 fractions, and reduced crystalline anisotropy. SEM and TEM analyses showed pH-dependent morphological variations, with increased aggregation being observed at lower pH values. GNMIOPs displayed exceptional magnetic behavior, with the highest saturation magnetization being observed in GNMIOPs prepared at pH 7.5 and 12.5 and subsequently washed with ethanol. The zeta potential measurements indicated a stability range for GNMIOPs spanning from −31.8 to −41.6 mV, while GNMIOPs synthesized under high-pH conditions demonstrated noteworthy antioxidant activity. Furthermore, it was explored how pH and washing solvent affected the morphology, roughness, and magnetic properties of GNMIOP-infused nanofiber membranes. SEM showed irregularities and roughness due to GNMIOPs, varying with pH and washing solvent. TEM confirmed better dispersion with ethanol washing. The magnetic response was stronger with ethanol-washed GNMIOPs, highlighting the influence of pH and washing solvent on membrane characteristics.

Synergistic Antioxidant and Preservative Potential of Tomato Extract–Magnetic Iron Oxide Nanoparticles in Bio-Coating and Food Applications

“…The coexistence of peaks from both cubic and monoclinic systems underscores the magnetic response of these particles, as visually presented in Figure 1b. This observation aligns with previous studies [40,50], wherein magnetic properties were explored under various pH conditions and calcination parameters. The XRD results in this study harmonize well with their findings, highlighting a substantial percentage of the magnetic phase.…”

“…Fragmentations in peaks around 1000-400 cm −1 indicate oxidation-reduction between different phases of iron oxide, justifying the magnetic response of the TEx-MIONPs, as reported in [50]. Surface analysis highlights nanoscale roughness and irregularities in the SEM micrographs, with potential implications for the nanoparticles' interactions in various applications, such as catalysis or drug delivery [40]. Further quantitative insights into surface characteristics can be gained through techniques like atomic force microscopy (AFM) or profilometry [53].…”

“…The pH was recorded and adjusted to 7.5 by adding NaOH (5 M) as necessary. The mixture was subjected to a reaction temperature of 60-80 • C for 3 h [39,40]. After the reaction, the mixture was cooled and washed, and the iron oxide nanoparticles were collected by filtration.…”

“…Surface analysis highlights nanoscale roughness and irregularities in the SEM micrographs, with potential implications for the nanoparticles' interactions in various applications, such as catalysis or drug delivery [40]. Further quantitative insights into surface characteristics can be gained through techniques like atomic force microscopy (AFM) or profilometry [53].…”

Agro-Waste Sweet Pepper Extract-Magnetic Iron Oxide Nanoparticles for Antioxidant Enrichment and Sustainable Nanopackaging

“…Simultaneously, a 5 M solution of NaOH was added to adjust the pH to 7.5, as needed. The mixture underwent manual stirring and a reaction temperature of 60–80 °C for 3 h until a dark brown precipitate was obtained [ 43 , 44 ]. Following the reaction, the precipitate was separated by filtration, and several washing cycles were performed to collect iron oxide nanoparticles.…”