Opportunities and Challenges in the Synthesis of Noble Metal Nanoparticles via the Chemical Route in Microreactor Systems.

The process of noble metal nanoparticle synthesis is complex and consists of at least two steps: slow nucleation and fast autocatalytic growth. The kinetics of these two processes depends on the reductant "power" and the addition of stabilizers, as well as other factors (e.g.

Chalcopyrite Leaching in the Presence of Isopropanol-The Kinetic and Mechanistic Studies.

Oxidative leaching, as a basic step of the hydrometallurgical process of pure copper production from chalcopyrite, is a slow process in which mineral acids with strong oxidants addition are usually used as a leaching medium. It was found experimentally that the copper leaching from chalcopyrite in the HSO-HO-HO system, in the presence of isopropanol (IPA) and under other conditions (HO concentration, rate of mixing and temperature), takes place with satisfactory rate and efficiency. To quantify how much the change of these crucial variables affects the rate of the process, experimentally obtained kinetic curves (conversion over time) were analyzed using a Shrinking Core Model (SCM).

The Kinetics of the Redox Reaction of Platinum(IV) Ions with Ascorbic Acid in the Presence of Oxygen.

In this work, the kinetics of the redox reaction between platinum(IV) chloride complex ions and ascorbic acid is studied. The reduction process of Pt(IV) to Pt(II) ions was carried out at different reagent concentrations and environmental conditions, i.e.

Determination of the Dielectric Constant of Niobium Oxide by Using Combined EIS and Ellipsometric Methods.

Combining ellipsometric and EIS methods, the dielectric constant ε for the oxide NbO at room temperature was determined. At first, the linear dependence between anodization voltage and oxide thickness was established in the form = 2.14 (± 0.

Batch Reactor vs. Microreactor System for Efficient AuNP Deposition on Activated Carbon Fibers.

The process of noble metals ions recovery and the removal small fraction of nanoparticles from waste solution is an urgent topic not only from the economic but also ecology point of view. In this paper, the use of activated carbon fibers (ACF) as a "trap" for gold nanoparticles obtained by a chemical reduction method is described. The synthesized nanoparticles were stabilized either electrostatically or electrosterically and then deposited on carbon fibers or activated carbon fibers.

On the Rate of Interaction of Sodium Borohydride with Platinum (IV) Chloride Complexes in Alkaline Media.

In this work, sodium borohydride was used as a strong reductant of traces of platinum complex ions. The investigations of the kinetics of redox reaction between platinum(IV) chloride complex ions and sodium borohydride were carried out. For the first time, the kinetic experiments were carried out in a basic medium (pH~13), which prevents NaBH from decomposition and suppresses the release of hydrogen to the environment.

Micro Droplet Formation towards Continuous Nanoparticles Synthesis.

In this paper, micro droplets are generated in a microfluidic focusing contactor and then they move sequentially in a free-flowing mode (no wall contact). For this purpose, two different micro-flow glass devices (hydrophobic and hydrophilic) were used. During the study, the influence of the flow rate of the water phase and the oil phase on the droplet size and size distribution was investigated.

Green method for efficient PdNPs deposition on carbon carrier in the microreactor system.

The synthesis of palladium nanoparticles and conditions of their deposition on active carbon fibers in the microreactor was described. All processes related with metal ion reduction, nucleation, and autocatalytic growth of particles as well as their deposition were carried out in the microreactor in only one cycle. Synthesis of palladium nanoparticles was carried out under different conditions, i.

From dynamic self-assembly to networked chemical systems.

Although dynamic self-assembly, DySA, is a relatively new area of research, the past decade has brought numerous demonstrations of how various types of components - on scales from (macro)molecular to macroscopic - can be arranged into ordered structures thriving in non-equilibrium, steady states. At the same time, none of these dynamic assemblies has so far proven practically relevant, prompting questions about the field's prospects and ultimate objectives. The main thesis of this Review is that formation of dynamic assemblies cannot be an end in itself - instead, we should think more ambitiously of using such assemblies as control elements (reconfigurable catalysts, nanomachines, etc.

Kinetic studies of nucleation and growth of palladium nanoparticles.

In this paper, the kinetic studies of nucleation and growth processes of palladium nanoparticles formation are presented. As a palladium precursor the chloride complex of Pd(II) and as a reductant l-ascorbic acid, were used. Kinetic studies were conducted under different experimental conditions such as initial concentration of metal ions, ascorbic acid, chloride ions as well as at different temperature and ionic strength.

The influence of the route of administration of gold nanoparticles on their tissue distribution and basic biochemical parameters: In vivo studies.

Background: The gold nanoparticles (AuNP's) exhibit interesting chemical and physical properties and for this reason are intensively tested in medicine. However there is a lack of information about toxicity of those nanoparticles as well as their excretion from the body. Thus, the aim of the present study was to investigate the influence of the route of administration of gold nanoparticles to rats on their distribution in tissues and excretion rate.

Tissue distribution of gold nanoparticles after single intravenous administration in mice.

Background: Nanoparticles (a part of matter which size is less than 100 nm) have numerous potential applications in biomedicine, due to their unique surface, electronic and optical properties. The goal of the present study was to examine the distribution of gold nanoparticles (GNPs) in mice after single intravenous administration.

Methods: Spherical GNPs were synthesized by chemical reduction of tetrachloroauric acid with ascorbic acid as a reductant.