The fine control of iron oxide nanocrystal sizes within the nanometre scale (diameters range from 2.5 to 14 nm) allows us investigate accurately size-dependence their structural and magnetic properties. A study growth conditions these nanocrystals obtained by thermal decomposition an oleate precursor in high-boiling point solvents has been carried out. Both type solvent used ligand/precursor ratio have systematically varied, were found be key parameters process. lattice all deduced X-ray...

Iron oxide nanoparticles (NPs) with average sizes in the range 4–28 nm have been obtained by varying different synthesis parameters of thermal decomposition an iron precursor (iron stearate) presence surfactants high boiling solvents. The affect NPs nucleation and growth steps, modifying stability stearate on which depend monomer formation concentration, agreement LaMer model. formation, is reaction time and/or temperature dependent, thus found to vary mainly as a function nature solvents...

Most studies on the synthesis of nanoparticles are currently focused controlled new morphologies, including core-shell structures, which expected to exhibit magnetic properties for uses in spintronics and recording media applications. In this study, structure, morphology, composition cubic-shaped carefully investigated compared those spherically shaped through use a combination techniques: X-ray diffraction (XRD) transmission electronic microscopy (TEM) combined with more sensitive...

Nanocomposites combining multiple functionalities in one single nano-object hold great promise for biomedical applications. In this work, carbon nanotubes (CNTs) were filled with ferrite nanoparticles (NPs) to develop the magnetic manipulation of and their theranostic The challenges both filling CNTs a high amount NPs functionalization form biocompatible water suspensions. We propose here process using as nanoreactors high-yield situ growth into inner cavity. At first, formed inside by...

Hydrogen production via water splitting requires efficient electrocatalysts to reduce the overpotential of anodic oxygen evolution reaction (OER) and cathodic hydrogen (HER). In this study, we investigated influence apparent shell thickness on electrocatalytic activity Fe3O4@CoFe2O4 core@shell nanoparticles, an noble metal-free OER catalyst in alkaline media. Three different types nanoparticles were synthesized by seed-mediated crystal growth cobalt ferrite pristine magnetite nanoparticles....

The best solution? A highly crystalline hybrid silica has been obtained through the hydrolysis of a precursor in solution phase. self-organized structure lamellar material consists diureido–phenylene bridging units (see picture); structural comparisons this and its molecular show existence similar hydrogen-bonding interactions both structures.

Iron oxide nanoparticles are widely used as a contrast agent in magnetic resonance imaging (MRI), and may be therapeutic for hyperthermia if they display particular high anisotropy. Considering the effect of shape on anisotropy, reproducible control is current synthesis challenge. By investigating reaction parameters, such iron precursor structure, its water content, but also amount surfactant (sodium oleate) reported to shape, with different composition were obtained, particular,...

Aqueous suspensions of dendronized iron oxide nanoparticles (NPs) have been obtained after functionalization, with two types dendrons, NPs synthesized either by coprecipitation (leading to naked in water) or thermal decomposition (NPs situ coated oleic acid an organic solvent). Different grafting strategies optimized depending on the synthetic method. The size distribution, colloidal stability isoosmolar media, surface complex nature as well preliminary biokinetic studies performed optical...

Spherical core–shell CoxFe1–xO@CoyFe3-yO4 nanoparticles (NPs) as well spherical and cubic shaped CoFe2O4 NPs were synthesized through a thermal decomposition method by adjusting parameters such the nature of precursors ligands. The use metal (iron and/or cobalt) oleates stearates in presence oleic acid ligand leads to NPs, due reducing environment provided oleate groups from precursors. By contrast, oleylamine favored less medium, which allows obtaining with homogeneous composition. In...

1D assemblies of magnetic nanoparticles are great potential for designing novel nanostructured materials with enhanced collective properties. In that challenging context, a new assembly strategy is presented to prepare chains well‐defined in structure and spatial arrangement. The iron oxide onto substrate controlled using “click” chemistry under an external field. Co‐aligned single nanoparticle separated by regular distances can be obtained this strategy. intrinsic high uniaxial anisotropy...

Calcium carbonate biomineralization uses complex assemblies of macromolecules that control the nucleation, growth, and positioning mineral with great detail. To investigate mechanisms involved in these processes, for many years Langmuir monolayers have been used as model systems. Here, we descibe use cryogenic transmission electron microscopy combination selected area diffraction a quasi-time-resolved technique to study very early stages this process. In way, assess evolution morphology,...

The dipolar interactions in monolayer and multilayer assemblies of iron oxide nanoparticles have been investigated as a function the nanoparticle size. magnetic properties nanocrystals various sizes measured for particles powders assembled mono- multilayers by Langmuir–Blodgett technique, compared to behavior non-interacting nanoparticles. It is shown that increasing lead higher blocking temperatures deviation from Néel–Brown law. Dipolar are found be stronger thin films powdered samples....

Core–shell nanoparticles (NPs), which consist in a ferrimagnetic (FIM)/antiferromagnetic (AFM) interface and result exchange bias coupling, became recently of primary importance the field magnetic nanoparticles. The enhancement some applications such as hyperthermia or storage media based on miniaturization devices is correlated to size reduction NPs, results decrease magnetocrystalline anisotropy blocking temperature. We present here synthesis Fe3−δO4@CoO core–shell NPs by one-pot...

The integration of chiral and magnetic properties has gained increasing interest due to its potential for enabling magneto-chiral phenomena. However, the development nanoscale systems that exhibit strong responsiveness both light fields remains largely underexplored. In this context, we investigate use silica nanohelices as a platform inducing circular dichroism (CD) in iron oxide nanoparticles (NPs). Two strategies are compared: an ex situ approach, where NPs synthesized independently then...

In CaCO3, biomineralization nucleation and growth of the crystals are related to presence carboxylate-rich proteins within a macromolecular matrix, often with organized β-sheet domains. To understand interplay between organic template mineral crystal it is important explicitly address issue structural adaptation during mineralization. this end we have developed series self-organizing surfactants (1−4) consisting dodecyl chain connected via bisureido-heptylene unit an amino acid head group....

Nowadays, nanoparticles are considered as the building blocks of future nanotechnological devices and development strategies for processing into thin films has become a strategic challenge. In this context, assembling spherically shaped iron oxide displaying various sizes cubic-shaped been investigated using Langmuir–Blodgett technique. Homogeneous dense monolayer multilayer have obtained on large areas. The organisation in studied by combining GISAXS image analysis SEM micrographs. quality...

A fluid nematic-like phase is induced in monodisperse iron oxide nanoparticles with a diameter of 3.3 nm. This supramolecular arrangement governed by the covalent functionalization nanoparticle surface cyanobiphenyl-based ligands as mesogenic promoters. The design and synthesis these hybrid materials study their properties are reported. In addition, modifications magnetic hybridized investigated function different grafted ligands. Owing to rather large interparticular distances (about 7 nm),...

Self-assembly of nanoparticles (NPs) into tailored structures is a promising strategy for the production and design materials with new functions. In this work, 2D arrays iron oxide NPs interparticle distances tuned by grafting fatty acids dendritic molecules at surface have been obtained over large areas high density using Langmuir–Blodgett technique. The anchoring agent Janus structure are shown to be key parameters driving deposition. Finally influence distance on collective magnetic...

Azide-terminated magnetic iron oxide nanoparticles have been assembled in 2D on alkyne-terminated self-assembled monolayers (SAMs) by the copper(i) catalyzed alkyne-azide cycloaddition (CuAAC) "click" reaction; kinetics of reaction is an important parameter to control interparticle distance and thus dipolar interactions.

Magnetic cobalt-based nanoparticles (NPs) with homogeneous size were selectively cast inside the channel of multiwalled carbon nanotubes (CNTs). The proposed synthesis method allows for filling only CNTs an unprecedented high density. act as "nanoreactors" and provide protection against oxidation.

Multilayer assemblies of iron oxide nanoparticles with tunable magnetic properties have been prepared by the layer-by-layer technique. The multilayer depend closely on stacking nonagglomerated and, in particular, interlayer distance between nanoparticles, which is defined thickness polyelectrolyte multilayers. Therefore, dipolar interactions were demonstrated to occur preferentially plane nanoparticle layers and result antiparallel coupling adjacent layers, modulated as a function distance.

Although single magnetic domain nanoparticles are very promising for many applications, size reduction usually results in low anisotropy and unblocked at room temperature, e.g., superparamagnetism. An alternative approach is core–shell featured by exchange bias coupling between ferro(i)magnetic [F(i)M] antiferromagnetic (AFM) phases. has been reported diverse nanoparticles, it difficult to compare these studies rationalize the effect of structural parameters on properties. Herein, we report...

Iron oxide raspberry grafted onto graphene/PEDOT:PSS layer-by-layer has been designed for supercapacitors.

Exchange coupled nanoparticles that combine hard and soft magnetic phases are very promising to enhance the effective anisotropy while preserving sizes below 20 nm. However, core–shell structure is usually insufficient produce rare earth-free ferro(i)magnetic blocked at room temperature. We report on onion-type prepared by a three-step seed mediated growth based thermal decomposition method. The core@shell@shell consists of core an external shell Fe3−δO4 separated intermediate Co-doped...