Structural characteristics of different types of nanoparticles synthesised in mesomorphic metal alkanoates

The class of thermotropic ionic liquid crystals (LCs) of the metal alkanoates possesses a number of unique properties, such as intrinsic ionic conductivity, high dissolving ability and ability to form time-stable mesomorphic glasses. These ionic LCs can be used as nanoreactors for the synthesis and stabilisation of different types of nanoparticles (NPs). Thus, some semiconductors, metals and core/shell NPs were chemically synthesised in the thermotropic ionic liquid crystalline phase (smectic A) of the cadmium octanoate (CdC₈) and of the cobalt octanoate (CoC₈). By applying the scanning electron microscopy, the cadmium and cobalt octanoate composites containing CdS, Au, Ag and core/shell Au/CdS NPs have been studied. NPs’ sizes and dispersion distribution of the NPs’ size in the nanocomposites have been obtained.     

Transformations of Peroxide Ozonolysis Products of (–)-α-Pinene and (+)-3-Carene by the Action of 4-Hydroxybenzohydrazide

Russian Journal of Organic Chemistry - Treatment of peroxide ozonolysis products of the bicyclic monoterpenes (–)-α-pinene and (+)-3-carene with 4-hydroxybenzohydrazide in methylene...     

Synthesis of Isonicotinic and Salicylic Acids Derivatives from (–)-α-Pinene and (+)-Δ3-Carene

Russian Journal of General Chemistry - Optically active cyclobutanediyl- and cyclopropanediylbisalkylidene dihydrazides of isonicotinic and salicylic acids were synthesized when the peroxide...     

Stress state of a transversely isotropic piezoceramic body with a spheroidal cavity

The exact solution is found to the three-dimensional electroelastic problem for a transversely isotropic piezoceramic body with a spheroidal cavity. The solutions of static electroelastic problems are represented in terms of harmonic functions. The case of stretching the piezoceramic medium at a right angle to the spheroid axis of symmetry is analyzed numerically. The dependence of the stress concentration factor on the geometry of the spheroid and the electromechanical characteristics of the material is studied.Translated from Prikladnaya Mekhanika, Vol. 40, No. 11, pp. 92–105, November 2004.This revised version was published online in April 2005 with a corrected cover date.     

Properties of new fibrous adsorbents with amidoxyme and hydrazidine groups

Data on sorption properties of new fibrous adsorbents with respect to heavy metals are presented. The POLYORGS 34 and POLYORGS 35 filled fibrous adsorbents and POLYORGS 33 fibrous adsorbent contain amidoxyme and hydrazidine groups. Is has been shown that these adsorbents can be used for the adsorption preconcentration of heavy, noble, and rare metals and radionuclides from aqueous salt solutions. Examples of using adsorbents under study for the dynamic preconcentration of copper from a 0.5 M NaCl solution during filtration through a series of disks, column, or adsorption cartridges are presented.     

Application of phosphorus- and nitrogen-containing organic compounds for the isolation of actinides and technetium from acid or basic aqueous solutions

The derivatives of ethers of phosphoric acid, namely O-(2-alkyl) (diethylcarbamoylmethyl) phenylphosphinates (O2ADECMPP), were synthesized and tested for liquid–liquid extraction of transuranium elements, lanthanides and technetium in meta-nitrobenzotrifluoride or 1,2-dichlorethane from acidic solutions. The O-(ethylhexyl) (diethylcarbamoylmethyl) phenylphosphinate (O2EHDECMPP) was used to prepare chelating granulated sorbents. The family of chelating fibrous ‘filled’ sorbents POLYORGS-type shows, according to preliminary experiments, that Pu and Tc at concentrations around 10^–5 M can be recovered almost completely. POLYORGS show fast kinetics for sorption processes. To cite this article: G.V. Myasoedova et al., C. R. Chimie 7 (2004).

Résumé

Utilisation de réactifs phosphorés et azotés pour la séparation des actinides et du technétium de milieux acides et basiques. Des dérivés de l’éther de l’acide phosphorique du type O-2-alkyl diéthylcarbamoylméthyl phénylphosphonates ont été préparés et testés pour extraire des éléments transuraniens, des lanthanides et du technétium dans le meta-nitrobenzène ou le 1,2-dichloroéthane, à partir de solutions aqueuses acides. Le dérivé O-éthylhexyl diethylcarbamoylméthyl phénylphosphonate a été utilisé pour préparer des échangeurs solides par effet de chélation. La famille des chélatants fibreux Polyorgs montre, dans des expériences préliminaires, que Pu et Tc, à des concentration de l’ordre de 10^–5 M, peuvent être complètement récupérés à partir de milieux acides contenant d’autres éléments. Ces composés présentent des cinétiques de sorption très rapides. Pour citer cet article : G.V. Myasoedova et al., C. R. Chimie 7 (2004).     

Surface activity at the planar interface in relation to the thermodynamics of intermolecular interactions in the ternary system: maltodextrin-small-molecule surfactant-legumin

We report on the effect of potato maltodextrins with variable dextrose equivalent (Paselli SA-2, SA-6 and SA-10) on the surface behavior at the air-water interface of the mixture: legumin+small-molecule surfactant. Distinct in nature small-molecule surfactants (model: sodium salt of capric acid, Na-caprate; and commercially important: a citric acid ester of monoglyceride, CITREM) have been under our consideration. The role of the structure of both of the maltodextrins and the small-molecule surfactants in the effect studied has been elucidated by measurements in a bulk aqueous medium of the enthalpy of their interaction from mixing calorimetry, value of weight average molecular weight of the maltodextrins and the thermodynamics of the pair maltodextrin-solvent and maltodextrin-protein interactions from laser static light scattering. The combined data of mixing calorimetry and light scattering suggest some complex formation between the small-molecule surfactants and the maltodextrins. Predominantly hydrophobic interactions along with hydrogen bonding form the basis of the complexes. The effect of the maltodextrins on the thermodynamics of the protein heat denaturation and thereby on the protein conformational stability in the presence of the small-molecule surfactants has been studied by differential scanning calorimetry. The interrelation between the thermodynamics of intermolecular interactions in a bulk and the surface behavior at the planar air-water interface of the ternary systems (maltodextrin+legumin+small-molecule surfactant) has been elucidated by tensiometry. The effect of the maltodextrins on the surface activity of mixtures of legumin with the small-molecule surfactants is governed by the competitive in relation to the protein interactions with the small-molecule surfactants and a subsequent change in the thermodynamic properties of the both biopolymers, which are favorable to the ternary complex formation.     

13C NMR study of the intermolecular interactions in the polyethylene glycol-cellulose acetate-solvent system

As a result of measuring the spin-lattice relaxation rates of¹³C nuclei of polyethylene glycol in different solvents in the presence of cellulose acetates, it was found that polyethylene glycol forms H complexes with cellulose acetate in nonaqueous solvents, and the probability of binding increases with a decrease in the molecular weight of the polyethylene glycol. The formation of H complexes results in an effect of inversion of the mobility of the polyethylene glycol molecules of different weights in concentrated solutions of a mixture of polymers. The value of the effect is determined by the donor-acceptor properties of the solvent and the degree of substitution of hydroxyl groups by acetate groups.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1766–1768, August, 1989.     

Sorption Preconcentration of Platinum-Group Metals with Filled Fibrous POLYORGS Sorbents

The sorption of platinum, palladium, and rhodium with fibrous filled POLYORGS sorbents was studied depending on the concentration of hydrochloric acid and the time of contact of the solution with the sorbent in the batch mode. The equilibrium and kinetic characteristics of the sorption of platinum with the POLYORGS 17-n sorbent were determined, on the basis of these data the conditions for the dynamic preconcentration of platinum from a 1 M HCl solution were calculated. Conditions were selected for the group preconcentration of palladium, platinum, and gold in the dynamic mode and for their subsequent determination in the sorbent. It was demonstrated that rhodium can be preconcentrated with the POLYORGS 17-n sorbent in the dynamic mode in the presence of tin chloride.     

Dependence of the mobility of molecular probes in cellulose acetate solutions on complexation and the solution structure

The spin echo technique with a magnetic field pulse gradient was used to measure the translational diffusion coefficients D of molecular probes in solutions of cellulose acetates in dimethyl sulfoxide. A linear dependence of coefficient D on the extent of substitution of the cellulose acetate was established and the sensitivity of D to the supermolecular structure of the polymer solution was demonstrated.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 470–472, February, 1990.