Solvated electron in liquid methanol. An example of a statistical species in chemistry

The methods of analysis of the statistical ensembles of trapping sites, before and after electron localization, for electrons in disordered media are surveyed. The review covers the computer-search methods for pre-existing traps in polar matrices, random field theory of disordered polar matrices and the path integral simulations of solvated electron. The common picture provided by all these methods is emphasized: the solvated electron is a unique in chemistry statistical species characterized by statistical distributions of the structural parameters, energy states, reactivity, etc. The numerical examples are provided by the simulations of the trapping sites and the solvated electron in liquid methanol.     

Blends of propylene-ran-ethylene and propylene-ran-(1-butene) copolymers: Crystal superstructure and mechanical properties

Blends of isotactic propylene-ran-ethylene (EP) and propylene-ran-(1-butene) (BP) copolymers with various comonomer content (2-3.1 wt.% ethylene, 9.9 wt.% 1-butene), were prepared in Brabender internal mixer at various compositions (25/75, 50/50, 75/25). Static, impact and dynamic mechanical behavior of copolymers and their blends was investigated. The crystalline structure was studied by DSC and SAXS analysis. For all copolymers the lamellar thickness, crystallinity degree and glass transition temperature are lower than those of iPP homopolymer, depending on the comonomer content. It was found that the copolymers exhibit improved impact strength as compared to plain iPP, due to lower crystallinity and higher mobility of chains within amorphous component. Moreover, the elastic modulus as well as the yield behavior of the examined samples resulted to depend primarily on the amount of the crystalline phase and the thickness of the lamellar crystals, respectively. A linear dependence of yield stress on the logarithm of reciprocal lamellar thickness was observed for blends and copolymers, supporting the concept of thermal nucleation of dislocations which control the crystallographic slip processes initiated at the yield point. The blends of BPS with either EPS or EP2 display complete miscibility in the entire range of composition and their mechanical properties are intermediate between those of plain components, changing gradually with the composition.     

Computer simulation of ion recombination in irradiated nonpolar liquids

A review of the results of computer simulation of the diffusion controlled recombination of ions is presented. The ions generated in clusters of two and three pairs of oppositely charged ions were considered. The recombination kinetics and the ion escape probability at infinite time with and without external electric field have been computed. These results are compared with the calculations based on the single-pair theory.     

Adsorption of Ni(II) from model solutions using co-precipitated inorganic oxides

The aim of this work was to obtain an inorganic oxide system containing silica and magnesium oxide, and characterized by specific physicochemical properties, in particular well-defined adsorption parameters. The preparation process was carried out according to a co-precipitation method using solutions of sodium silicate and selected inorganic magnesium salt. The oxide system obtained (MgO·SiO₂) was used as a support (adsorbent) of nickel(II) ions, whose precursors were model solutions of nitrates. The effectiveness of the adsorption process was evaluated using many different analytical techniques, including atomic absorption spectroscopy, energy dispersive X-ray spectroscopy and equivalent point titration. Moreover the stability of adsorbent/adsorbate bonding was estimated. The oxide systems—adsorbents—used in the process were also analyzed according to their physicochemical properties, especially changes in adsorption parameters. The last part of the study involved evaluation of the kinetics of the adsorption process depending on time and the pH of the reaction system.     

Preparation of peptide-functionalized gold nanoparticles using one pot EDC/sulfo-NHS coupling

Although carbodiimides and succinimides are broadly employed for the formation of amide bonds (i.e., in amino acid coupling), their use in the coupling of peptides to water-soluble carboxylic-terminated colloidal gold nanoparticles remains challenging. In this article, we present an optimization study for the successful coupling of the KPQPRPLS peptide to spherical and rodlike colloidal gold nanoparticles. We show that the concentration, reaction time, and chemical environment are all critical to achieving the formation of robust, peptide-coated colloidal nanoparticles. Agarose gel electrophoresis was used for the characterization of conjugates.     

Tri-(nitrato)-bis-(hexamethylenetetramine)-nona-(aquo) neodymium (III): Synthesis,crystal structure,IR and Raman spectroscopy

This paper reports the structural and spectroscopic properties of tri-(nitrato)-bis-(hexamethylene-tetramine)-nona-(aquo)neodymium (III). The crystals are monoclinic, space groupP2₁/n,Z=4, witha=17.902(4),b=9.335(2),c=18.489(4)Å, B=112.07(2)°. The crystal structure consists of one [Nd(NO₃)₂(H₂O)₆]⁺ cation, two NO ₃ ^– anions coordinated to the neodymium atom, two hexamethylene tetramine molecules, third free NO ₃ ^– anion and three water molecules. The structure was refined to a finalR index 0.039 and weightedR _w 0.039 for 6221 observed reflections. The IR and Raman spectra are fully consistent with the crystallographic results.