Microfluidic Synthesis of Iron Oxide and Oxyhydroxide Nanoparticles

Abou‐Hassan, Ali; Sandre, Olivier; Cabuil, Valérie

doi:10.1002/9780470622551.ch9

Cited by 8 publications

(13 citation statements)

References 112 publications

(89 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Controlling the salt metathesis of iron precursors into iron hydroxides followed by sol-gel reaction is not a straightforward task because it occurs instantaneously upon mixing; thus, the conditions have to be adequately set. The Fe 3+ / Fe 2+ phase [32]. Maghemite (γ-Fe 2 O 3 ) can be obtained from magnetite by simple oxidation in an acidic medium with Fe 3+ nitrate salts, or by leaving magnetite nanocrystals in contact with oxygen from ambient air, accelerating the formation of the thermodynamically favored maghemite compound.…”

mentioning

confidence: 99%

Fundamentals and advances in magnetic hyperthermia

Périgo

Hemery

Sandre

et al. 2015

Applied Physics Reviews

673

526

View full text Add to dashboard Cite

Nowadays, magnetic hyperthermia constitutes a complementary approach to cancer treatment. The use of magnetic particles as heating mediators, proposed in the 1950s, provides a novel strategy for improving tumor treatment and, consequently, patient quality of life. This review reports a broad overview about several aspects of magnetic hyperthermia addressing new perspectives and the progress on relevant features such as the ad hoc preparation of magnetic nanoparticles, physical modeling of magnetic heating, methods to determine the heat dissipation power of magnetic colloids including the development of experimental apparatus and the influence of biological matrices on the heating efficiency.Comment: 104 pages, 28 figures. Manuscript accepted for publication in Applied Physics Review

show abstract

mentioning

confidence: 99%

Fundamentals and advances in magnetic hyperthermia

Périgo

Hemery

Sandre

et al. 2015

Applied Physics Reviews

673

526

View full text Add to dashboard Cite

show abstract

“…Coprecipitation experimental studies (including bio-mimetic mineralization experiments) have claimed an indirect nucleation process during the formation of magnetite, i.e. the formation of transient phases in the early stages and their subsequent transformation into magnetite (4,11,(15)(16)(20)(21)(22)(23)(24)(25)(26). As above commented, the olation and the oxolation processes are the main sequential colloidal-interacting reactions.…”

Section: Indirect Nucleation Of Magnetite: Reaction Mechanism and Kineticsmentioning

confidence: 92%

“…For example, the most widely used coprecipitation reaction (2Fe 3+ + Fe 2+ + 8OH − → Fe3O4 + 4H2O) to produce magnetite under laboratory and at industrial scale, is performed by using aqueous solutions containing ferric (Fe 3+ ) and ferrous (Fe 2+ ) ions, to which a base is added at moderate temperatures (<100 °C). The controlled addition of iron solution into alkaline solution or a fast mixing of both solutions have also been investigated (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Herein, several studies have claimed that magnetite crystallization is preceded by the formation of various transient crystalline or poorly-crystallized phases (akageneite, goethite, lepidocrocite, ferrihydrite, ferric hydroxide and ferrous hydroxide) that may become sequentially transformed into magnetite, depending on several control parameters such as the addition rate of solution, the ratio OH/(Fe +3 +Fe +2 ), the initial pH, the molar fraction of Fe +3 (Fe +3 /(Fe +3 +Fe +2 )) and the hydrodynamics conditions (11,(26)(27)(28)(29)(30).…”

Section: Introductionmentioning

confidence: 99%

Direct and Indirect Nucleation of Magnetite Nanoparticles from Solution Revealed by Time-Resolved Raman Spectroscopy

Montes-Hernandez

Findling

Renard

2021

Crystal Growth & Design

View full text Add to dashboard Cite

Magnetite is a widespread inorganic or bio-mineral with very specific and extraordinary chemical properties in terms of acid-base and oxidation-reduction behavior, thermal stability and oxygen mobility. Despite the existence of many synthesis methods, the formation mechanisms of this mineral are actively investigated and frequently debated. The co-precipitation reaction (2Fe 3+ + Fe 2+ + 8OH − → Fe3O4 + 4H2O) is the most widespread method to synthesize magnetite under laboratory conditions and at industrial scale. However, the early stages of magnetite formationnucleation events and precursors/transient phases formationare still questioned and their kinetics is poorly characterized. Here, we perform two series of experiments that differ by how the solutions are mixed: i) injection of an iron-rich solution into an alkaline aqueous solution; and ii) injection of an alkaline solution into an iron-rich solution. We show that dynamic in situ Raman spectroscopy provides invaluable information on the direct and indirect nucleation of magnetite nanoparticles (<15nm) from aqueous solution. When a mixed-valent iron solution (0.5M Fe 2+ + 0.5M Fe 3+ ) is injected (2.3 or 12 ml/minute) into an alkaline solution (4M of NaOH); dark colloidal particles form instantaneously and the magnetite signal is rapidly detected in Raman spectra after 3 or 7 minutes, depending of the injection rate. This result demonstrates that the mixed-valent iron is instantaneously dehydrated leading to the formation of magnetite-like colloidal (or primary) particles peaking in the range 674-678 cm -1 in the Raman spectra, with peak position stabilizing rapidly at 673 cm -1 . Conversely, when alkaline solution is added into the mixed-valent iron solution, Raman spectroscopy reveals a complex reaction mechanism and kinetics. Firstly, iron dehydration (315 cm -1 ) and formation of green rust (500-503 cm -1 ) as transient phase related to olation process are detected and interpreted by the formation of hydroxo bridges accompanied with 3 expelling of molecular water. Secondly, green rust and available ferric iron (ions or colloids) react to nucleate magnetite nanoparticles via an oxolation process related to the formation of oxo bridges accompanied with the expelling of hydroxylated water. We also quantified the nucleation time of magnetite and the hydrophilic-to-hydrophobic change in the suspension by the temporal behavior of bending mode of molecular water. Our results show that, under our experimental conditions, amorphous transient phases during direct or indirect magnetite formation from ionic solutions do not exist or that such phases do not show a specific Raman signature.

show abstract

“…With such objectives, new types of reactors have been developed and studied over the recent decades. Decreasing the dimensions of the chemical reactor was found to be a solution to improve mass and heat transfer of the reactive media, minimizing the undesired gradients often encountered in bulk [ 1 , 2 , 3 , 4 , 5 ]. Despite their small size, high production capacities can be reached in such reactors when chemical syntheses are performed under continuous-flow conditions, often called milli/micro/nano-fluidic syntheses.…”

Section: Introductionmentioning

confidence: 99%

High Temperature Continuous Flow Syntheses of Iron Oxide Nanoflowers Using the Polyol Route in a Multi-Parametric Millifluidic Device

2021

Self Cite

View full text Add to dashboard Cite

One of the most versatile routes for the elaboration of nanomaterials in materials science, including the synthesis of magnetic iron oxide nanoclusters, is the high-temperature polyol process. However, despite its versatility, this process still lacks reproducibility and scale-up, in addition to the low yield obtained in final materials. In this work, we demonstrate a home-made multiparametric continuous flow millifluidic system that can operate at high temperatures (up to 400 °C). After optimization, we validate its potential for the production of nanomaterials using the polyol route at 220 °C by elaborating ferrite iron oxide nanoclusters called nanoflowers (CoFe2O4, Fe3O4, MnFe2O4) with well-controlled nanostructure and composition, which are highly demanded due to their physical properties. Moreover, we demonstrate that by using such a continuous process, the chemical yield and reproducibility of the nanoflower synthesis are strongly improved as well as the possibility to produce these nanomaterials on a large scale with quantities up to 45 g per day.

show abstract

Microfluidic Synthesis of Iron Oxide and Oxyhydroxide Nanoparticles

Cited by 8 publications

References 112 publications

Fundamentals and advances in magnetic hyperthermia

Fundamentals and advances in magnetic hyperthermia

Direct and Indirect Nucleation of Magnetite Nanoparticles from Solution Revealed by Time-Resolved Raman Spectroscopy

High Temperature Continuous Flow Syntheses of Iron Oxide Nanoflowers Using the Polyol Route in a Multi-Parametric Millifluidic Device

Contact Info

Product

Resources

About