Fe$_3$O$_4$ magnetic nanoparticles (MNPs) were synthesized by a co-precipitation method using sodium citrate and oleic acid as modifiers. Phase composition and microstructure analysis indicate that the sodium citrate and oleic acid have been successfully grafted onto the surface of Fe$_3$O$_4$ MNPs. The magnetic behaviors reveal that the modification can decrease the saturation magnetization of Fe$_3$O$_4$ MNPs due to the surface effect. Fe$_3$O$_4$ MNPs modified by sodiumcitrate and oleic acid show excellent dispersion capability, which should be ascribed to the great reduction of high surface energy and dipolar attraction of the nanoparticles.
The present study investigates the effect of different reaction times on the crystallinity, surface morphology and size of iron oxide nanoparticles. In this synthetic system, aqueous iron (III) nitrate (Fe(NO$_3$)$_3\cdot9$H$_2$O) nonahydrate, provided the iron source and triethylamine was the precipitant and alkaline agent. The as-synthesised iron oxide nanoparticles were characterised by X-ray diffraction (XRD), Rietveld analysis, Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Prolonged reaction times indicated the change on nanoparticle shape from elo…
The general topic of energy is regarded to be one of the most important areas for any research and development activities at the start of the twentyfirst century. Therefore, large research efforts are already based on or will be targeted on the development of clean fuels to replace fossil fuels, the improvement of the existing resources and the discovery of new sustainable energy resources, the establishment of new efficient ways to store sustainable energy, and the replacement of the existing high energy consuming technologies with the more energy efficient ones. The latter concept has result…
The development of simple, versatile strategies for the synthesis of gold nanoparticles (AuNPs) on semiconducting transition metal dichalcogenides (TMDC) layers is of increasing scientific and technological interest in photocatalysis, optical sensing, and optoelectronics sectors, but challenges exist on the nucleation and hybridization of AuNPs with the TMDC basal plane. At present, the widely used aqueous solution approaches suffer from poor dispersion of produced hybrids as well as from limited growth and coverage of the AuNPs on the TMDC semiconducting plane, since Au nanoclusters nucleate …
Plasmas at atmospheric pressure are presented as a simple, fast, and versatile tool for the synthesis or/and the grafting of noble metallic NPs (Au, Pt) on substrates. In this study, noble metal NPs are generated either by the reduction of a gold salt in an aqueous medium by microplasma or either by the decomposition of a platinum or gold organometallic in the post-discharge of an atmospheric plasma torch. The latter can also be used for the grafting of NPs from a commercial colloidal solution
Delafossites like CuGaO2 have appeared as promising p-type semiconductor materials for opto-electronic applications mainly due to their high optical transparency and electrical conductivity. However, existing synthetic efforts usually result in particles with large diameter limiting their performance relevant to functional electronic applications. In this article, we report a novel surfactant-assisted hydrothermal synthesis method, which allows the development of ultrafine (~5 nm) monodispersed p-type CuGaO2 nanoparticles (NPs). We show that DMSO can be used as a ligand and dispersing solvent …
Until now, the fabrication of electrocatalysts to guarantee long life of fuel cells and low consumption of noble metals remains a major challenge. The electrocatalysts based on metals or metal oxides which are used today are limited by the complexity of their synthesis processes and require several steps before depositing the catalysts on the substrate. Herein is described a chemical synthesis process that consists of a single-step synthesis and direct deposition of catalysts nanoparticles such as gold (Au), palladium (Pd) and platinum (Pt) in the thickness of a carbon-fibers-based porous tran…
A recent area of interest in thermal applications has been nanofluids, with extensive research conducted in the field, and numerous publications expounding on new results coming to the fore. The properties of such fluids depend on their components, and by the use of combined and complex nanoparticles with diverse characteristics, the desirable qualities of multiple nanoparticle suspensions can be obtained in a single mixture. The paper covers these hybrid nanofluids, the techniques for their synthesis, their properties, characteristics, and the areas of debate and outstanding questions.
Water dispersion of nanometric yttria stabilized zirconia (YSZ) particles synthesized by continuous hydrothermal synthesis are transferred into nanoinks for thin film deposition. YSZ nanoparticles are synthesized in supercritical conditions resulting in highly dispersed crystals of 10 nm in size. The rheology of the colloid is tailored to achieve inkjet printability (Z) by using additives for regulating viscosity and surface tension. Inks with a wide range of properties are produced. A remarkable effect of nanoparticles on the ink printability is registered even at solid load < 1% vol. In part…
Magnetic nanoparticles (MNPs) have been extensively used as tiny heating sources in magnetic hyperthermia therapy, contrast agents in magnetic resonance imaging (MRI), tracers in magnetic particle imaging (MPI), carriers for drug/gene delivery, etc. There have emerged many magnetic nanoparticle/microbeads suppliers since the last decade, such as Ocean NanoTech, Nanoprobes, US Research Nanomaterials, Miltenyi Biotec, micromod Partikeltechnologie GmbH, and nanoComposix, etc. In this paper, we report the physical and magnetic characterizations on iron oxide nanoparticle products from Ocean NanoTe…
Over the last decades, the use of magnetic nanoparticles in research and commercial applications has increased dramatically. However, direct detection of trace quantities remains a challenge in terms of equipment cost, operating conditions and data acquisition times, especially in flowing conditions within complex media. Here we present the in-line, non-destructive detection of magnetic nanoparticles using high performance atomic magnetometers at ambient conditions in flowing media. We achieve sub-picomolar sensitivities measuring $\sim$30 nm ferromagnetic iron and cobalt nanoparticles that ar…
The thirst for fabricating environment friendly silver nanoparticles (AgNPs) as biosensors via the green route is highly demanded among researchers due to their free of cost and less impact on creating pollution compared to other methods involving risk interference from toxic chemicals as reducing, stabilizing and capping agents. Here, for the first time, Coffee arabica leaf extracts (CAE) were used for the production of highly stable AgNPs in an easy and eco-friendly manner. Within ten minutes, we can visually confirm the reduction of Ag+ to Ag0 from a change of yellow color to dark brown by …
Magnetic nanoparticles (MNPs) have been extensively used in drug/gene delivery, hyperthermia therapy, magnetic particle imaging (MPI), magnetic resonance imaging (MRI), magnetic bioassays, etc. With proper surface chemical modifications, physicochemically stable and non-toxic MNPs are emerging contrast agents and tracers for in vivo MRI and MPI applications. Herein, we report the high magnetic moment, irregularly shaped γ'-Fe4N nanoparticles for enhanced hyperthermia therapy and T2 contrast agent for MRI application. The static and dynamic magnetic properties of γ'-Fe4N nanoparticles are chara…
This chapter describes the synthesis and some characteristics of magnetic iron oxide nanoparticles, mainly nanocubes, and focus on their self-assembly into crystalline cuboids in dispersion. The influence of external magnetic fields, the concentration of particles, and the temperature on the assembly process is experimentally investigated.
Silicon nanoparticles possess unique size-dependent optical properties due to their strong electric and magnetic resonances in the visible range. However, their widespread application has been limited, in comparison to other (e.g. metallic) nanoparticles, because their preparation on monodisperse colloids remains challenging. Exploiting the unique properties of Si nanoparticles in nano- and micro-devices calls for methods able to sort and organize them from a colloidal suspension onto specific positions of solid substrates with nanometric precision. Here, we demonstrate that surfactant-free Si…
Nanomedicine research started exploring the combination of therapy and diagnostics, so-called theranostics, to offer a more flexible care with improved outcome. As magnetic nanoparticles show great potential in many diagnostic and therapeutic applications, they are prime candidates to be used in a theranostic setting. This perspective gives an overview of state-of-the-art magnetic nanoparticle-based imaging techniques and theranostic applications and discusses their opportunities and challenges. To address these challenges and exploit these opportunities to the fullest, we provide three promis…
