Synthesis of In2O3nanoparticles by thermal decomposition of a citrate gel precursor

This paper describes the synthesis of indium oxide by a modified sol–gel method, and the study of thermal decomposition of the metal complex in air. The characterization of the intermediate as well as the final compounds was carried out by thermogravimetry, differential thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and small angle X-ray scattering. The results show that the indium complex decomposes to In₂O₃ with the formation of an intermediate compound. Nanoparticles of cubic In₂O₃ with crystallite sizes in the nanosize range were formed after calcination at temperatures up to 900°C. Calcined materials are characterized by a polydisperse distribution of spherical particles with sharp and smooth surfaces.     

Diagnostics of an inductively coupled plasma in oxygen

Spatial time-integrated and space-time resolved profiles of excited atoms of oxygen were measured by optical emission spectroscopy for inductively coupled plasma (ICP) in oxygen. The discharge was sustained by a single turn coil supplied by 13.56 MHz RF generator delivering 100 and 200 W of power. The spatial emission profiles give the anatomy of the discharge required in order to understand the basic kinetics of ICP. Two types of nonuniformities are observed, azimuthal anisotropy and radial nonuniformity, both caused by spatially dependent energy supply to the electrons. Our experimental results show that oxygen is much more affected by azimuthal anisotropy and radial nonuniformity than argon. It is due to a different role of metastable atoms in kinetics of excitation, whereby stepwise excitation in oxygen is less probable than in argon. Optical emission data are supplemented by Langmuir probe measurements of electron densities and plasma potentials. Electrons gain energy from the time varying fields close to the coil, and the energy is not redistributed along the radius before it is dissipated in excitation, thus the observations are not consistent with the nonlocal theory predictions for the range of pressures, geometry, and power covered in this paper     

Electron density calculation for polyoxymethylene in cylindrical coordinates by a new fourier method

The electron density of the polyoxymethylene molecule was calculated in cylindrical coordinates by a newly derived Fourier method. The density due to hydrogen could be obtained in addition to that from carbon and oxygen. This method is generally applicable to a helical polymer whose unit cell contains only one molecule composed of a number of chemical repeat units in the fiber identity period.     

Structural studies of polyesters. VIII. Molecular and crystal structure of polydiketene

The molecular and crystal structures of polydiketene were studied by infrared spectroscopy and x-ray diffraction. It was confirmed from the infrared spectra that diketene molecules in the crystal polymerize by ring opening upon γ-ray irradiation. The unit cell of the product as polymerized is orthorhombic, P22₁2₁-D₂³, with a = 5.43 Å, b = 8.94 Å, and c (fiber axis) = 7.75 Å. Two molecules pass through the unit cell The molecule has a conformation shown by the Fischer projection for a lefthanded (2/1) helix; The internal rotation angle around the O—C bond is nearly gauche (?84°), unlike other polyesters. On the basis of x-ray analysis, several molecular conformation models were selected by utilizing calculations of intramolecular interaction energies.     

Chromatography of inorganic ions on sulfoethyl cellulose layer in mixed sulfuric acid-organic solvent media

Summary The thin-layer chromatographic behavior of 49 inorganic ions has been systematically studied on layers of sulfoethyl (SE) cellulose, a strongly acidic cation-exchanger, with binary solvent mixtures consisting of sulfuric acid and an organic solvent such as methanol or acetone. The characteristic retention on the cellulose layer can be recognized for some ions forming sulfato complexes in the acid-organic solvent medium, and some aspects of the behavior are discussed. Chromatographic separations of analytical interest are also demonstrated on the SE-cellulose layer with acid-methanol and acid-acetone solutions used as mobile phases.     

Structural studies of polyethers. IX. Planar zigzag modification of poly(ethylene oxide)

A new crystal modification was found in poly(ethylene oxide) stretched about two-fold after necking at room temperature. An x-ray diffraction analysis indicated that the planar zigzag molecule passes through a triclinic unit cell with parameters α = 4.71 Å, b = 4.44 Å, c (fiber axis) = 7.12 Å, α = 62.8°, β = 93.2°, and γ = 111.4°. The space group is P1 ?C_i¹. Packing of the molecule is very similar to that of monoclinic polyethylene.     

Two-dimensional images of radiative and metastable excited stateradial profiles for an inductively coupled plasma in argon

Inductively coupled plasma (ICP) was shown to be characterized by a substantial degree of stepwise excitation due to a large density of metastable atoms and an even larger population of electrons. The kinetics of metastables strongly affects the structure of the discharge and we have applied laser absorption spectroscopy to establish the density profile of argon metastables Ar(1s₅) in a single turn coil geometry. At the same time the radial profiles of the radiative Ar(3p₅) state obtained by using a computer-aided tomography are significantly different indicating the effect of electron induced quenching and stepwise processes in kinetics of the two states     

A Novel Thermocell System Using Proton Solvation Entropy

The entropy change associated with proton-coupled electron transfer (PCET) reactions significantly enhance the Seebeck coefficient (S_e) of thermocells. A redox pair of [Ru(H_xim)₆]^2+/3+ (Him=imidazole, x=0≈1) releases three protons in their one-electron redox reactions in thermocells, which gave a remarkably high S_e of −3.7 mV K⁻¹ as confirmed by temperature-dependent square wave voltammetry. The value of S_e is proportional to the redox reaction entropy (ΔS_rc), which increased with the number of dissociating protons. This result demonstrates the utility of PCET reaction toward efficient thermoelectric conversion.     

Structures and phase transition of multi-layered water nanotube confined to nanochannels

We placed nanometer-scale water-tube clusters with phase transition within a porous crystal formed from molecular blocks specifically designed to investigate the molecular dynamics of confined water molecules.