Synthesis and properties of zinc nanoparticles: The role and prospects of radiation chemistry in the development of modern nanotechnology

Zinc-containing nanoparticles stable in the liquid phase are synthesized by the radiation chemical reduction of zinc ions in solutions of inverse micelles. The effects of the absorbed radiation dose and the size of the micelle water pool on the spectral characteristics of samples are studied. The HPLC and electron microscopy results indicate that the composition of nanoparticles synthesized depends on the salt nature. Original Russian Text ? A.A. Revina, E.V. Oksentyuk, A.A. Fenin, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 6, pp. 613–618.     

The structure and composition of iron nanoparticles stabilized by carboxymethyl chitin resulting from ultrasonic irradiation

The methods of sonochemistry and “green” nanotechnology were used to develop a single-stage process to transfer iron nanoparticles from their micellar solution in isooctane to aqueous solution of carboxymethyl chitin excluding an intermediate stage of producing iron nanoparticulate dispersion in water. The structure and dimensions of iron nanoparticles in a macromolecular system based on 6-O-carboxymethyl chitin were examined using X-ray microanalysis and selected-area electron diffraction analysis, transmission electron microscopy (TEM), and atomic force microscopy (AFM). According to TEM and AFM data, the sizes of ultradispersed particles were within the range of 2–4 nm. The X-ray investigations indicated that iron nanonoparticles in the carboxymethyl chitin–iron nanoparticles system consisted mainly of zero-valent alpha-iron particles (α-Fe⁰) and a number of magnetite Fe₃O₄ nanoparticles. Because both types of particles exhibit magnetic properties, these metal–polymer nanocomposites may have a wide range of applications in medicine, electronics, biotechnology, ecology, and catalysis.     

Study of nanoparticles synthesized in reverse micelles using liquid chromatography method

Liquid chromatography, which makes it possible to investigate interphase processes, is an additional method for studying inverse micellar systems without changing their properties in the process of sample preparation. In the case of using these systems to synthesize nanoparticles (NPs), it becomes possible to determine their adsorption characteristics, to investigate the processes of modifying surface adsorbents by NPs, to determine their sizes, and to divide them into fractions according to their sizes and surface properties of the micelles. The method is simple and rapid and permits one to use standard, relatively inexpensive equipment and can be applied in many physicochemical studies of NPs synthesized in micellar solutions.     

Synthesis and properties of nickel nanoparticles and their nanocomposites

For the first time, nickel nanoparticles are synthesized in reverse micelles by a radiation-chemical method. The particles are shown to be spherical with sizes of an order of magnitude of 1–100 nm. Nickel particles are oxidized by air oxygen to nickel oxide nanoparticles, retaining their shape and nanoscale dimensions. Adsorption of nickel-metal nanoparticles on silica is studied by spectrophotometry.

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Original Russian Text ? S.V. Gornostaeva, A.A. Revina, L.D. Belyakova, O.G. Larionov, 2008, published in Fizikokhimiya Poverkhnosti i Zashchita Materialov, 2008, Vol. 44, No. 4, pp. 400–403. An erratum to this article can be found online at http://dx.doi.org/.     

Physicochemical and catalytic properties of ruthenium nanoparticles obtained in reverse micelles

We synthesized ruthenium nanoparticles in reverse-micelle solutions using radiation-chemical (under anaerobic conditions) and chemical reduction of ions (in the presence of oxygen). The optical absorption spectra recorded during nanoparticle formation differed depending on the synthesis conditions, storage, and the phenomena of adsorption/desorption on the carrier. The size of ruthenium nanoparticles was determined by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Nanoparticles varied in size, shape, and size distribution according to the experimental conditions. We deposited ruthenium nanoparticles on the Γ-Al₂O₃ carrier and studied their catalytic activity in an isotopic exchange reaction.     

Studies of adsorption of palladium nanoparticles on silicon oxide using methods of spectrophotometry and atomic force microscopy

In this work, the method of UV-VIS spectrophotometry was used to study the adsorption of palladium nanoparticles Pd NPs on silicon dioxide (silochrome S-120). Pd NPs were synthesized using a radiation-chemical method in micelle 0.15 M solutions of the AOT surfactant at different degrees of hydration ω₀ = [H₂O]/[AOT]. It is shown that adsorption depends on the structure of nanoparticles, conditions of synthesis in reverse micelles, including the ω₀ value, which determines the NP size, as well as the chemical and physicochemical properties of the silochrome surface.     

A study of the adsorption of silver nanoparticles by high-performance liquid chromatography

The method of high-performance liquid chromatography has been used to study the adsorption of stable silver nanoparticles, which were obtained by radiation-chemical synthesis in reverse micellar solutions of H₂O + Ag⁺/Aerosol OT/isooctane composition. Adsorption was conducted on polar and nonpolar sorbents. It has been determined that almost all nanoparticles are retained on nonpolar sorbent C18; however, their binding is not strong. After accumulation of a particular amount of nanoparticles, they leave a column with effluent. It has been shown that the adsorption and optical properties of silver nanoparticles almost do not change after the adsorption-desorption cycle on C18. It has been determined that, on polar silica gel, the adsorption of silver nanoparticles proceeds less intensely (fewer than half of the particles move to the near-surface layer of the sorbent; however, their interaction with surface is very strong and they were not desorbed. For nanoparticles and the molecules of the micelle-forming agent Aerosol OT, adsorption isotherms have been plotted. Based on the obtained results, possible mechanisms of adsorption of nanoparticles on the surface of polar and nonpolar sorbents have been considered.     

Adsorption and oxidation processes in modern nanotechnologies

Among the fields in which Russian science can chalk up, of primary importance are nanotechnologies involving nanosized-particles-based modern materials with preset properties. The specific properties of metallic nanoparticles open up wide possibilities of preparing novel materials in electronics, effective catalysts, filtering elements, biosensors, medications with high biological activity for medical, biotechnological, and agricultural applications. Physical chemistry is extremely important in the creation of interdisciplinary basic foundation of nanochemistry and applied nanotechnology of XXI century [1–4]. The methods of synthesis, in inversed micelles, of metallic nanoparticles, stable in liquid phase and in nanocomposites and showing characteristic bands of optical UV-vis absorption, allow using modern physicochemical methods of studying the nanostructure formation, properties, and polyfunctional activity [5–10]. The results of the studies of adsorption processes of the metal nanosized aggregates in solutions, obtained by using chromatography (high-performance liquid chromatography, thin-layer chromatography, gas chromatography) and demonstrating the important role of active surface centers and molecular interactions, may serve as a theoretical basis in producing new nanocomposite materials with unique properties [10–12].     

Cytogenetic characteristics of H3 oxide induced myeloid leukemia in Wistar rats

Frequency and spectrum of chromosomal aberrations were studied in hemopoietic cells of Wistar rats myeloid leukaemia induced by the prolonged exposure to tritium oxide. Differences in quantitative and structural damages of chromosomes were revealed by the cytogenetic assessment of eighteen rats with acute myeloid leukaemia (AML) and six rats with chronic myeloid leukaemia (CML). The most characteristic chromosomal aberrations for AML appeared to be rearrangements in chromosomes 1-3. In CML translocations by one of chromosomes 15-20 coupled with defects in the groups of chromosomes 5-10 seemed to be nonrandom.