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The phase composition of the interaction product of zinc acetate with hydrogen peroxide in a dispersed aqueous phase of a reverse micellar solution based on oxyethylated Brij 30 surfactant and decane as a dispersion medium is analyzed by powder X-ray diffraction (XRD). Along with ZnO2 nanoparticle, the isolated product is found to contain needle-like microcrystals that, according to the single crystal XRD analysis, are zinc lactate dihydrate [Zn(lact)2(H2O)2]: a = 6.0196(3) A, b = 11.9068(4) A, c = 14.3878(7) A, Z = 4, space group P212121. The coordination environment of the Zn atom is a distorted octahedron: Zn–О distances are 2.051(2)-2.099(3) A, ∠О–Zn–О bond angles are 76.16° and 76.14°. Chelate rings are bent along the О…О line at 22.18° and 11.54°. The Hirshfeld surface (complex sphericity 0.79, asphericity 0.16) is constructed and intermolecular contacts are analyzed. A comparative crystal chemical analysis with the known [Zn(lact)2(H2O)2]·H2O structure is performed.

The deposition of coatings of Au and ZnO nanoparticles (NPs) on glass, semiconductor silicon, polyethylene terephthalate, and polystyrene substrates was studied. Deposition was carried out using relatively concentrated dispersions of particles in ethanol (approximately 5–10 mM Au, ZnO), which showed limited time resistance to coagulation and sedimentation, but returned to their original dispersed state by ultrasonic treatment before each cycle of deposition of NPs. The NPs of Au and ZnO were stabilized by abietate and acetate ions, respectively. Simple coatings from Au or ZnO NPs and a combined coating from a mixture of Au and ZnO NPs, as well as two-layer combined coatings with alternating layers of Au/ZnO and ZnO/Au NPs, were obtained by drop casting and the proposed method of deposition from the capillary layer of the dispersion with the use of a linker. The formation of coatings on transparent substrates was studied by means of UV–Vis spectroscopy. Coatings were characterized by SEM, EDX, XRD, PL, UV–Vis and surface resistance methods. The effect of heat treatment on coatings characteristics was tested.

The study addresses layer-by-layer formation processes and properties of gold nanoparticle films deposited from reverse micellar solutions of Brij 30 surfactant on rigid glass and flexible polymer (PET) substrates. The films are of interest for transparent electronics and optical sensorics. The spectrophotometric studies of film formation revealed linear relationships between the extinction of growing film at definite wavelengths and the number of nanoparticle deposition cycles, and their parameters were determined. The effects of concentrations of gold and 1,2-ethanedithiol as an interlayer linker in the initial solutions on the film growth were elucidated. Data on the composition, morphology, optical spectra, and surface resistance of gold nanoparticle films, and changes of these characteristics during heat treatment in air and in boiling ethanol were gained using X-ray diffractometry, scanning electron and atomic force microscopy, UV-Vis spectroscopy, and electrical resistance measurements.

To measure the total neutron cross sections, the authors developed a convenient technique using silicon semiconductor detectors with the simple and compact detecting system. The created technique was used to measure A + n total cross sections at the energy En = 14.1 MeV for several nuclei in different mass region. The neutron generator NG-150 in D + T regime of neutrons generation is used as fast neutrons source. The results of measurements and their comparison with the appropriate literature values are also presented.

The Geant4 code is used for Monte Carlo modeling of the angular distribution of the neutron yield from an 3H(d, n)4He reaction in a tritium target, and the effect the collimator unit has on the neutron flux. The number of all nuclear reaction channels in a 232Th + natU (50/50%) target per 14.1-MeV neutron is also found, along with the optimum size of the target for the maximum yield of secondary neutrons.

We studied the usefulness of dispersions of gold nanoparticles (Au-NPs) stabilized by abietic acid for manufacturing films on glass and silicon substrates and composites with nanosized and powder materials exemplified by SiO2 and TiO2 NPs, expanded graphite (EG), carbon nanotubes (CNTs), a porous carbon material (PCM), PCM containing 6% nitrogen, and CeO2 powder.

Gold nanoparticles (NPs) with the average core diameter d Au = 6.8 ± 1.6 nm have been synthesized in reverse micelles of the oxyethylated surfactant Brij 30. It has been shown that thin NP films can be produced directly from a micellar solution with the use of glass substrates functionalized with aminosilane. Synthesis of NPs and film formation have been studied by UV-Vis spectroscopy, photon correlation spectroscopy, X-ray diffraction, TEM, SEM, and AFM.

Comparison of extraction properties of macrocyclic calix[4,6]arenethiaethers (CATE) with their acyclic analogs R2S (R = C6H13, C8H17) for the recovery of [Rh(NO2)3(H2O)3]0 rhodium form from nitric acid solutions was carried out. Rhodium recovery with CATE (0.05 M) in the absence of accelerating additives under optimal conditions exceeds 90% at 5–10-fold preconcentration and is only 1–3% for R2S (1 M). Extraction kinetics was studied and hypothesis on the mechanism of multiple acceleration of rhodium recovery was proposed for CATE extraction, the mechanism includes the formation of intermediate product of colloidal- chemical nature on account of the surface activity of the macrocycle and its reaction with rhodium accompanied by rhodium chelation to the sulfur atoms of neighboring fragments of the macrocycle. The obtained results are of interest for the development of methods for the isolation of fission rhodium from nitrate–nitrite nitric acid solutions.

A method is advanced for preparing gold nanoparticles (NPs) at 50°C in aqueous acrylamide (AAm), which has the dual function of a reducing agent for HAuCl4 and a protective ligand for NPs. Nanoparticles have gold cores with the average size d Au = 20.9 ± 3.6 nm. The growth kinetics of NPs has been studied. Films of NPs have been produced on glass, silica, silicon, and polyethylene terephthalate (PET) substrates. The NPs and films have been characterized by UV-Vis and IR spectroscopy, X-ray powder diffraction, transmission and scanning electron microscopy, and atomic-force microscopy.

The growth kinetics of gold nanoparticles (NPs) during the reduction of HAuBr4 by hydrazine in the reverse micelles of oxyethylated surfactant Tergitol NP 4 was studied in situ by UV–vis spectroscopy. Kinetic mechanism includes the steps of slow, continuous nucleation and fast, autocatalytic surface growth. Both steps are under kinetic control of the precursor reduction. The rate of nucleation is limited by reaction in the droplets of the aqueous phase forming the cores of reverse micelles, and growth rate is limited by the reaction on the surface of gold NPs growing inside the micelles. The chemical mechanism of reduction of halogenated forms of gold AuX4– by hydrazine is the same in the case of X = Cl, Br and includes the equilibria of formation and redox decomposition of the intermediate complexes AuIII(N2H4)X3 and AuI(N2H4)X. The initial form of AuX4– (X = Cl, Br) does not affect the size of the final NPs synthesized in micellar solution of oxyethylated surfactant.

Hydrophilic gold nanoparticles stabilized with isonicotinic acid (INA) were prepared by reduction of HAuCl4 with sodium borohydride in the presence of INA in water, dimethylformamide, and dimethyl sulfoxide. The main condition for the preparation of good quality particles is to maintain reagent concentration ratio HAuCl4 : INA : NaBH4 = 1 : 2 : (5–10) at cAu ≤ 0.5 mM. Reaction products in water are mainly spherical primary particles with gold nuclei of 2–7 nm in diameter, those in dimethylformamide are secondary coalescent particles with nuclei of spheroid or slightly faceted shape 2–12 nm in diameter and larger elongated agglomerates from 15 to 100 nm long. Framework structures composed of chaotically agglomerated particles were obtained at HAuCl4 : INA ratio larger than 1 : 2. By the example of precipitate of particles prepared in dimethylformamide and on the basis of data of chemical and thermal analysis, XPD, and IR spectroscopy, it was shown that the product contains gold, INA anion, acetone, water, sodium cations, and oxygen boron compounds. The particles obtained as precipitate or concentrate are well redispersible in water and polar solvents. The particles in colloid dispersions are in aggregated state and suffer gradual coagulation and sedimentation, which are not irreversible, and dispersed state can be restored by ultrasound treatment. The particles stabilized by INA may be of interest as initial product for preparation of nanomaterials for biomedical purposes.

Hydrophobic gold nanoparticles were prepared via the reduction of HAuCl4 by sodium borohydride in the presence of abietic acid (AA) in nonaqueous polar media based on dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethanol, and isopropanol. The particles prepared in DMF had spherical gold cores, with a narrow size distribution and the average diameter dAu = 7.1 ± 1.0 nm, and a protective shell formed of abietic acid anions and sodium cations. A violet nanoparticle sediment separated by centrifugation was stored under DMF and could be used for preparing colloidal dispersions of nanoparticles in polar solvents. Ethanol dispersions of nanoparticles were most resistant to sedimentation. The nanoparticles were shown to be useful for sensing nonaqueous polar media.

The kinetics of thiourea synthesis of CdS nanoparticles (NPs) in reverse microemulsions of Tergitol Np-4/n-decane was studied in the temperature range of 313−333 K by spectrophotometry, photon-correlation spectroscopy, and transmission electron microscopy. The formation of NPs is described by the kinetic model, including two consecutive steps: homogeneous nucleation in a solution as the first step and the autocatalytic growth of NPs due to heterogeneous reaction on a continuously increasing surface as the second step. Effective rate constants of the steps (k1 = 1.52 × 10–2–1.75 × 10–3 s–1 and k2 = 4.9 × 10–1–5.1 × 10–2 M–1 s–1) and effective activation energies (Ea1 = 156 and Ea2 = 149 kJ/mol) were estimated in the pseudo-first-order reaction with respect to cadmium (cCd = 0.9 mM, cThio = 9 mM). The obtained constants were used to calculate the dependence of nanoparticle diameter on the synthesis time (d3 ∼ t). The calculated values correlate well with experimental data of photon-correlation spectroscopy ...

A comparison was made for extraction systems based on the mixtures of calix[n]arenes phosphorylated at the upper and lower rims (PCA, n = 4 and 6) with dioctyl sulfide (DOS) for recovery of rhodium in the form of [Rh(H2O)3(NO2)3]0 from acid nitrate-nitrite media. Because of inertness of rhodium compounds, the main attention was devoted to extraction kinetics. The kinetic efficiency of DOS + PCA systems was found to be much higher than that for DOS alone, whereas the components of the mixtures do not extract rhodium. Alkyl(ethyl)calixphosphine oxides are the most promising, they behave as accelerating additives in extractant mixtures. Extraction kinetics of [Rh(H2O)3(NO2)3]0 species was studied and extraction systems were selected to develop method for the recovery of fission rhodium.

The synthesis of Au nanoparticles through the reduction of HAuCl 4 with sodium borohydride in a mixture of ethanol and isopropanol in the presence of tris(2-aminoethyl)amine is presented. The resulting powder preparation is a mixture of primary particles with the average diameter of golden cores 3.2 ± 0.6 nm, and secondary particles that were formed as a result of agglomeration of the primary ones and have core diameter up to 20 nm. The Au content of the preparation is 1.94% because Au nanoparticles have voluminous protective shells composed of the adducts of tris(2-aminoethyl)amine, acetone and boric acid, formed due to hydrogen bonding. The preparation is hydrophilic and allows one to obtain colloid solutions in water and polar solvents like acetone, isopropanol, dimethylsulphoxide, and in chloroform under ultrasonic treatment.

The crystals of the [Pd3(μ-OH)(μ-CH3COO)5] complex are obtained and characterized using powder and single crystal X-ray diffraction and IR spectroscopy. The crystal structure (a = 15.6942(6) A, b = 11.7190(3) A, c = 9.7871(3) A, V = 1800.05(10) A3, space group Pna21, Z = 4) is formed from neutral trinuclear cyclic molecules of [Pd3(μ-OH)(μ-CH3COO)5], in which the OH− group, together with five CH3COO− anions, is a bridge ligand.

The growth kinetics of silver nanoparticles (AgNPs) during the reduction of AgNO3 by hydrazine in the droplets of dispersed aqueous phase encapsulated in the reverse micelles of oxyethylated surfactant Triton N-42 with decane as disperse medium was studied in situ by UV–vis spectroscopy. The mechanism of the process includes two steps that are slow, continuous nucleation and fast, autocatalytic surface growth. Both steps are under kinetic control and are limited by the rate of Ag+ reduction. The rate of nucleation is limited by reaction in the droplets of the aqueous phase forming the cores of reverse micelles, and the rate of the growth is limited by the reaction on the surface of AgNPs growing inside the micelles. The reduction of Ag+ is a second-order process with respect to N2H4. It includes the formation of the intermediate complex Ag(N2H4)+ and its reaction with another N2H4 molecule. The concentration effects of N2H4 (c′N2H4) and NH3 (c′NH3) as competing ligand, medium effects of ionic strength (I)...

Methods for preparing gold nanoparticles (NPs) surface-stabilized with di-(2-ethylhexyl)dithiophosphoric acid (DTPA) and tris(2-aminoethyl)amine (TAEA), which endow the nanoparticles with hydrophobic and hydrophilic properties, are described. In the case of DTPA, Au-NPs are first synthesized with surfactant shells by means of reducing [AuCl4]− with hydrazine in inverted micelles of oxyethylated Triton N-42 in a low-polarity medium of decane; then, the micelles are destroyed by polar chloroform in the presence of DTPA, which has a great affinity to gold due to its sulfur donor atoms and substitutes for the surfactant on the surface of the nanoparticles. In preparing hydrophilic nanoparticles, [AuCl4]− is reduced with solid NaBH4 directly in a nonaqueous solution of TAEA based on an ethanol and 2-propanol (3: 10) mixture. The nanoparticles are characterized by elemental analysis (for Au, C, H, N, and Na), X-ray powder diffraction, electronic absorption spectra, IR spectra, photon-correlation spectra, and transmission electron microscopy (TEM).

The feasibility of preparing energy-saturated salts (NH4NO3, KNO3, and NaBH4) in powders with various particle sizes in microemulsion systems based on oxyethylated surfactant Tergitol NP-4 has been demonstrated. Powders were isolated by destroying microemulsions with acetone. The regions of micellar synthesis have been determined depending on the solubilization capacities and concentrations of the reagents and salts at a fixed Tergitol NP-4 concentration (0.25 mol/L). The morphologies and particle sizes of the thus-prepared salt powders were characterized by scanning electron microscopy (SEM), X-ray powder diffraction, differential scanning calorimetry (DSC), differential thermal analysis (DTA), and thermogravimetry; the hydrodynamic radii of microemulsions were characterized by photon-correlation spectroscopy.

The kinetics of the growth of gold nanoparticles during the reduction of tetrachloroauric acid by hydrazine in dispersed aqueous solution encapsulated by reverse micelles of Triton N-42 surfactant (with decane as dispersion medium) was studied by means of spectrophotometry. According to DLS data, at a set value of solubilization capacity V s/V o = 0.005 initial micelles have an aqueous core hydrodynamic diameter d c = 3.6±0.2 nm. The final particles obtained after full reduction of AuIII have a metallic core of defect-free single-crystalline gold with a narrow size distribution and average core diameter d Au = 7.7 ± 1.4 nm as shown by TEM. The rate of the particle growth is limited by the rate of gold reduction. The process kinetics corresponds to the model consisting of two stages of reduction AuIII → AuI → Au0. The stages involve the formation and redox decay of the intermediate complexes Au(N2H4)Cl3 and Au(N2H4)Cl, and each stage proceeds via two routes: (1) homogeneous in the dispersed aqueous phase, and (2) heterogeneous on the particle surfaces. Reactions taking route (2) are autocatalytic because they proceed with participation of the surface atoms of particles as the final products of AuIII reduction. The dependencies of observed rate constants on reagent concentrations, temperature, and solubilization capacity of the micellar solution are studied.

The effect of additions of hydrophobic dioctyl sulfide (L) on the kinetics of dissolution of gold nanoparticles in the interaction with a dispersed aqueous hydrochloric solution of H2O2 in Triton N-42 reverse micelles (decane was the dispersion medium) was studied spectrophotometrically. The process consists of a two-stage oxidation Au0 → AuCl2− → AuCl4− at the surface of gold particles; the first stage occurs in two ways: a spontaneous reaction and an autocatalytic reaction involving AuCl4− ions. With small additions of L (cL < cAu), only spontaneous oxidation of Au(0) to Au(I) takes place because Au(I) is completely bound in an inert complex AuLCl. When unbound L is exhausted, the newly formed AuLCl is accumulated in micellar shells, changes the properties of the medium inside the micelles, and affects the rate constant of the autocatalytic reaction, which increases with increasing cL. At high concentrations of L, the coagulation of particles occurs instead of their dissolution, because of the deterioration of the protective properties of micellar shells as a result of the ingression and accumulation of dioctyl sulfide molecules on account of selective adsorption on gold particles. The rate constants of all stages of dissolution and coagulation are determined.

The products of the extraction treatment of Rh(III) and Pd(II) nitrate-nitrite solutions are studied. The [Rh(Thio)6](NO3)3·3H2O and [Pd(Thio)4](NO3)2 complex salts are extracted and an X-ray diffraction analysis of single crystals is performed (BRUKER X8 APEX automated diffractometer, MoKa radiation, graphite monochromator, two-dimensional CCD-detector). [Rh(Thio)6](NO3)3·3H2O crystallographic characteristics are as follows: a = 15.1857(3) A, b = 10.7292(2) A, c = 18.8524(4) A, β = 105.165(1)°, P21/c space group, Z =4; [Pd(Thio)4](NO3)2: a = 5.8013(4) A, b = 7.0981(5) A, c = 11.4991(8) A, α = 99.963(2)°, β = 101.410(2)°, γ = 102.229(2)°, P —1 space group, Z = 1.

Our spectrophotometric study of the kinetics of dissolution of silver nanoparticles by nitric acid inside inverted micelles of Triton N-42 (a nonionic surfactant) verified the universal character of the mechanism for this type of process, which includes the interaction of surface metal atoms with an oxidizer in two routes: either with (autocatalysis) or without newly formed ionic species of the oxidized metal. Effective rate constants for both routes are independent of the value of solubilization capacity (Vs/Vo is the ratio of the volume of the dispersed aqueous phase to the volume of the micellar solution); the solubilization capacity is useful to control the micelle and particle sizes: k1 = 0.018±0.003, 0.010±0.003, and 0.012±0.003 s−1 and k2 = 2.5±0.8, 1.5±1.1, and 1.4±0.4 L/(mol s) for 100 Vs/Vo = 1, 2, and 3%, respectively.

We studied nonequilibrium distribution of inert rhodium(III) in extraction by dihexyl sulfide (DHS)and alkylanilinium nitrate mixtures from joint nitrate solutions of triaquatrinitrorhodium (0.1–4 g/L Rh) and palladium (0–2 g/L Pd). We discovered the effect of increasing rhodium recovery in the presence of palladium. This effect has a kinetic nature and arises from the fact that bis(alkyl sulfide) palladium(II) species catalyze the reaction between dihexyl sulfide and a rhodium intermediate based on alkylanilinium nitrate micelles. Depending on initial rhodium and palladium concentrations, the extraction system provides effective distribution factors for rhodium in the range DRh* = 8−300 and rhodium recoveries of 43–97% with ∼100% palladium recovery; single 5-min phase contact at 35°C ensures the 10-fold concentration of both metals in the extract. Our results are useful for developing processes for recovering fission rhodium from spent nuclear fuel.

The dissolution of gold nanoparticles as a result of a reaction with dispersed aqueous solution of Cl− and H2O2 solubilized in Triton N-42 reversed micelles (an oxyethylated surfactant) in n-decane was studied photocolorimetrically. An adequate description of the process kinetics is provided by the following autocatalytic scheme (in a Cl− + H2O2 excess): Au0 → Au+, Au0 + Aun+ → 2Au3+, n = 1 and 3. The reactions involve the formation and redox decomposition of intermediate complexes with the oxidizer on the surfaces of metallic particles. Dimensional factors associated with gold particles (the surface and reactivity of gold particles change during the process) and micelles (as nanoreactors) affect the process kinetics. The first effect is taken into account when data processing is performed in terms of the current number and effective charge density of surface gold atoms; therefore, it does not affect the observed rate constants kd1 and kd2. The second effect makes kd1 and kd2 dependent on the micelle size through changing the quality of the aqueous medium and the reactivity of the reaction components, mainly the activity of water and its hydration and adsorption abilities.

The reduction of Au(III) with hydrazine monohydrate in micellar Triton N-42 solutions was shown to be an autocatalytic reaction. Its rate constants were calculated. The growth of a gold nucleus proceeded as a result of surface reduction until the polar micelle nanocavity was completely filled. Calculations according to the Derjaguin-Landau-Verway-Overbeck theory showed that the fate of nanoparticles formed depended on interparticle interaction energy. At a small radius of particles, high surface potential, and fairly thick surfactant surface layer, stable systems were formed. The coagulation zones were calculated depending on the structural parameters of nanoparticles and micelles. If a nanoparticle grew larger than 6.1 nm at a surface potential lower than 10 mV and surface layer thickness ∼1.6 nm, the potential well depth exceeded 3/2 kT in magnitude, and coagulation occurred in the system.

Using the methods of X-ray photoelectron spectroscopy (XPES), X-ray phase analysis, gamma-resonance (Mossbauer) spectroscopy, thermogravimetry of solid samples and atomic absorption, and atomic emission spectroscopy for solutions, the forms of occurrence of nonferrous metals in oxyhydroxide sediments (nitration hydroxides, NH) from nitration of refining of rhodium, iridium, and ruthenium are investigated. According to the XPES data, nitration hydroxides involve oxidized and unoxidized (selenium) transition metals, namely, Fe(III), Sn(II), Te(IV), Cu(I), Cu(II), Ni(II), Pb(II), As(III), Se(0), and Se(IV), as well as nonmetals O, Cl, and C. All nitration hydroxides are formed mainly by an X-ray amorphous phase (>90%). During heating of nitration hydroxides up to t = 900°C in an inert atmosphere, dehydration of hydroxides and crystallization of certain phases take place, but the X-ray amorphous phase amounts to more than 50%. Purely oxide phases or mixed oxide phases Fe3O4, SnO2, CuIFeIIIO2, and Pb2O3 (NH-1); Ni0.4Fe2.6O4, CuIFeIIIO2, and CuNiSnO4 (NH-2); and Fe3O4, Fe2O3, and SnO2 (NH-3) are formed in this case.

Extraction preconcentration of gold(III) by mixed Triton N-42 plus dioctyl sulfide (DOS) micelles from acid sulfate-chloride solutions was studied. The distribution ratio increases from 200 to 1200 as the DOS concentration rises from 0 to 0.25 mol/L (positive synergetic effect). Analysis of extraction equilibria shows that mixed micelles are key contributors into gold(III) extraction compared to Triton N-42 micelles and DOS molecular species in n-decane. Introduction of DOS at the synthesis stage increases the rate constants for gold reduction by hydrazine and enhances the coagulation of nascent nanoparticle

The dissolution of silver nanoparticles in their reaction with aqueous HNO3 solubilized to an reverse micelle solution of sodium bis(2-ethylhexyl)sulfosuccinate in decane is studied spectrophotometrically. A physicochemical model is advanced for quantifying the process kinetics on th basis of the following autocatalytic scheme: Ag0 + H+ + NO 3 − → Ag+ + products (k 1), and Ag0 + Ag+ + NO 3 − → 2Ag+ + products (k 2). The effective rate constant k 2 decreases with decreasing solubilization capacity V S/V O (where V S is the volume of the solubilized dispersed aqueous phase and V O is the volume of the micelle solution); the solubilization capacity determines the size of the micelle cavities in which the reaction between Ag0 and HNO3 occurs: k 2 = 74 (V S/V O) · 100% ≈ 3.8%), 41 (2.9), and 35 (2.0) L/(mol s). The effective constant k 1 is determined with a high uncertainty; the effect of V S/V O on k 1 has the opposite tendency.

The distribution of Au(III) between an acid (3 mol/l HCl) aqueous phase and a micellar Triton N-42 solution in n-decane was studied as a function of the concentration of Na2SO4 (0–3.55 mol/l). The high distribution coefficients (200–500) allow 50-fold absolute concentration to be performed at a 90% extraction. Au0 nanoparticles were obtained by the injection solubilization of a reducing agent (hydrazine) into micellar extracts. At low solubilization capacities (≤1 vol %) and high reducing agent concentrations (≥0.2 mol/l) in Triton N-42 micelles, stable systems of Au0 nanoparticles suitable for the spectrophotometric determination of gold were obtained. At high solubilization capacities and low hydrazine concentrations, reduction was accompanied by coagulation and sedimentation processes. These processes were studied by spectrophotometry and the static and dynamic light scattering methods.

The manifold enhancement of the rhodium extraction efficiency from nitric acid solutions of triaquatrinitrorhodium is discovered with the use of two-component mixed extractants based on alkylaniline (AA), dihexyl sulfide (DHS), dihexyl sulfoxide (DHSO), tributyl phosphate (TBP), and oxime ACORGA P5100. A mixture of unimolar solutions of alkylanilinium nitrate and DHS is found to be the most efficient extractant: at 35°C, this mixture quantitatively extracts rhodium within 5 min from aqueous solutions containing 0.06 to 3 mol/L HNO3. The extraction kinetics are studied. The following two-stage extraction mechanism is substantiated: the equilibrium of formation of a colloidal-chemical intermediate involving [Rh(H2O)3(NO2)3], HNO3, and (BHNO3)p (an associated form of the alkylanilinium salt) and the reaction of the intermediate with DHS (the rate-controlling stage).

The growth kinetics of silver nanoparticles upon silver(I) reduction with sodium citrate in an aqueous solution solubilized to a reverse micellar solution of sodium bis(2-ethylhexyl) sulfosuccinate in decane is studied spectrophotometrically under constant conditions of irradiation of the reaction mixture with visible light. The formal kinetics of the process corresponds to an autocatalytic mechanism. The effective rate constants of growth of silver nanoparticles, unlike those of gold nanoparticles, are independent of the size of the inner micellar cavity when its radius changes from 2 to 6 nm. This is most likely due to a great effect of the photochemical factor or Ag+ localization in the inner surface layer of the micelles on the rate constants.

Single crystals of the [PdL2(NO2)2] complex were obtained for the first time, where L is di-n-butylsulfide. Single crystal and powder diffraction studies provided new data on the molecular and crystal structure of this compound.

In order to use low-level fission palladium in technology, the paladium must be purified to a high degree with respect to foreign radionuclides with close chemical properties—ruthenium, antimony, and silver. The results of a simulation of an optimized two-cycle extraction scheme for extracting and refining palladium on the basis of one extractant—an aromatic solution of petroleum sulfides: first cycle with nitrate and second cycle with chloride system—are examined. The behavior of trace concentrations of silver is investigated and it is shown that total deep removal of silver from palladium of not less than 4.107–40 in the first cycle and 106 in the second cycle with a small number of extraction, washing, and reextraction steps can be attained. 2 figures, 3 tables, 6 references.

The experimentally determined total purification factors for palladium relative to silver (first cycle 102, second cycle >103) and rhodium and ruthenium (first cycle >104, second cycle >10) are greater than 105. In connection with the insufficient sensitivity of the atomic absorption method for monitoring and the relatively high value from the control run, we could not determine the true values of the purification factors in some operations of the second extraction cycle and for precipitation of palladosammine. The noted chemical aspects of the behavior of precious metals in extraction systems with petroleum sulfides lead to an estimate of the purification factors for palladium at the 108 level. In particular, the total purification factors increase by 10–100 times when the extraction is carried out in both cycles with W:O=10:1 (F=(W:O)/Dj, where j is the component to be separated [10]). Larger-scale laboratory testing of the proposed flow diagram for recovery and refining of palladium using Ag, Pd, Ru, Rh, and Sb will allow us to experimentally confirm that such estimates are realistic.

The article summarizes experiments performed on the extraction of palladium from spent nuclear fuels. Palladium extraction from high-level nitric acid solutions was performed using diesel fuels and petroleum sulfides. Petroleum sulfide extraction systems with aromatic solvents provided the highest selectivity for palladium. Experimental results for refinement of palladium after extraction are also summarized. 14 refs., 4 tabs.

A method for the preparation of [Pd(NH3)4Cl2]Cl2 through the oxidation of [Pd(NH3)4]Cl2 with a mixture of HCl and HNO3 acids (3 : 1) in an aqueous-ammonia solution was proposed. The composition of the product was confirmed by X-ray diffraction and chemical analyses and IR and Raman spectroscopy. The yield of the product was higher than 90%, and the content of the main substance was estimated as at least 95%. The crystallographic parameters of [Pd(NH3)4Cl2]Cl2 were determined. The salt was found to be isostructural to Gros salt [Pt(NH3)4Cl2]Cl2.

With the aid of the Mannich reaction, from diacetylenic alcohols and 1,3-alkadiynes, various types of dialkylamino derivatives of 1,3-diynes were synthesized.

1. Some diacetylenic primary amines were synthesized from tertiary diacetylenic chlorides prepared from the corresponding alcohols. 2. Alkylation and Mannich reactions of 1,1-dimethyl-2,4-pentadiynylamine were studied. 3. It was shown that diacetylenic hydrocarbons containing a tertiary alkyl group can be synthesized from 5-chloro-5-methyl-1,3-hexadiyne.

Gold nanoparticles (AuNPs) were synthesized in the organic solution by means of the reduction of HAuCl4 by hydrazine in reverse micelles of oxyethylated surfactant Triton N-42, with decane as the dispersion medium. To isolate the powder of particles, the micelles were destroyed with chloroform in the presence of di-(2-ethylhexyl) dithiophosphoric acid as a surface protecting agent. According to the results of several experiments, the yield is within the limits of 90–98%, calculated for gold. The obtained preparations are dark blue hydrophobic powders containing aggregated but not agglomerated gold nanoparticles, as well as microcrystals (∼0.08–0.2 μm) of NaCl. The powders get re-dispersed in weakly polar organic solvents with the formation of colloidal solutions. The shape of the nanoparticles is spherical. Their nuclei are gold single crystals with a narrow size distribution; their diameter (d Au) is about two times as large as the diameter of the aqueous nucleus (d c) of initial micelles: d Au = 7.7 ± 1.4 nm (d c = 3.6 nm) and 8.8 ± 1.5 nm (4.6 nm). The preparations were studied by means of dynamic light scattering, atomic force microscopy, transmission electron microscopy, UV–vis spectroscopy, IR spectroscopy, X-ray powder diffraction, and thermogravimetric and elemental analyses. In the case of the particles with d Au = 8.8 nm, the product is a mixture of AuNPs and the salt with the molar ratio Au/NaCl ≈ 1:4.54, while the gross composition of AuNPs per one gold atom is estimated as Au(C16H34O2PS2Na∙2N2H4)0.16 with the number of gold atoms in one particle ∼21,000.

Studies have been made on embryos of two hen lines selected by their reaction to cold stress (highly and lowly reactive ones). The adrenals of 16-day chick embryo react to the injection of the ACTH by synthesis of glucocorticoids and by their secretion into the blood. The rate of this reaction is higher in highly reactive line of hens. The hypothalamo-hypophyseal-adrenal system in chicks begins to respond to the increase in the environmental temperature by the synthesis and secretion of glucocorticoids already during embryo-genesis. In 18-day embryos, this reaction is more evident in highly reactive line.