Size-Tunable Magnetite Nanoparticles from Well-Defined Iron Oleate Precursors

Abstract

The synthesis of iron oxide nanoparticles with control over size and shape has long been an area of research, with iron oleate being arguably the most successful precursor. Issues with reproducibility and versatility in iron oleate-based syntheses remain, however, in large part due to the mutable nature of its structure and stoichiometry. In this work, we characterize two new forms of iron oleate precursor that can be isolated in large quantities, show long-term stability, and have well-defined stoichiometry, leading to reproducible and predictable reactivity. Synthesis with these precursors is shown to produce iron oxide nanoparticles in a tunable size range of 4–16 nm with low size dispersity and properties consistent with magnetite in the superparamagnetic size regime.

Quantifying superparamagnetic signatures in nanoparticle magnetite: a generalized approach for physically meaningful statistics and synthesis diagnostics

“…2a , S3a–e and Table S1 † ). 15 The percent relative standard deviation (%RSD) among all sample diameters exhibits a notable degree of consistency, falling between 9.88% and 12.97%. Briefly, a stoichiometric powder form of iron oleate was used in the high temperature decomposition of iron oleate with octadecene and oleic acid as the solvent and surfactant, respectively.…”

“…1 and S1†). In nanomaterials, specific models have been employed to interpret magnetic moment vs. magnetic field in terms of structure 9,10 and degree of crystallinity, 11–13 as well as nanoscale-specific properties such as size, 14,15 shape, 16,17 and surface. 18,19…”

Deciphering the parameters to produce highly reproducible and scalable iron oxide nanoparticles

“…S11†). 50,65,66 It is worth noting that the reactions with 3 months, 6 months, and 1 year-old iron oleate with octadecene rendered similar sizes and shapes, suggesting that just like its amount, the age of the precursor is not a critical factor once iron oleate has been properly prepared and preserved.…”

“…It also calls for a need to re-evaluate our reporting of such application-oriented NPs. 49,50 In this work, we evaluate how size and shape are affected when using different precursors and solvents. The thermal decomposition method was chosen for the synthesis as it is the most commonly used method for the preparation of IONPs for biomedical applications due to its several advantages, including narrow size distribution, good crystallinity, and high saturation magnetization values.…”

Plant-Mediated Synthesis of Magnetite Nanoparticles with Matricaria chamomilla Aqueous Extract

“…For instance, temperature and reaction time play a crucial role in particle size, with the process occurring in two distinct steps: nucleation and crystal growth [ 10 , 13 ]. Therefore, understanding the complex relationship between the synthetic parameters and the properties of NPs is crucial for the design of NPs tailored to specific applications [ 3 , 4 , 14 , 15 ].…”