Sorption and partial molar volumes of gases in poly(ethylene-co-vinyl acetate)

Sorption and dilation properties of polymer-gas systems involving poly(ethylene-co-vinyl acetate) and N₂, CH₄, or CO₂, have been investigated at pressures up to 50 atm at temperatures of 10–40°C. Sorption isotherms for low-solubility gases (i.e., CH₄ and N₂) can be described by Henry's law, and those for high-solubility gas (i.e., CO₂) by Flory-Huggins dissolution equation. Dilation isotherms are similar in contour to the corresponding sorption isotherms. From the obtained sorption and dilation data, partial molar volumes of the gases in the polymer were determined as a function of temperature. Thermal expansivity of dissolved CO₂ molecules was estimated at ca. 2.4 × 10^?3°C^?1 from the temperature dependence of partial molar volume. The expansivity is smaller than that of liquid CO₂ and larger than those of the polymer and organic liquids. © 1994 John Wiley & Sons, Inc.     

A resolvent expansion theorem for the Fourier transform of the retarded Green function and its application to the absorption bandshape of chromophore aggregates

A resolvent expansion theorem is developed for the Fourier transform of the retarded Green function. The resolvent expansion theorem coupled with a decorrelation approximation for a statistical average over the vibrational sublevels of the electronic ground state is applied to a theoretical formulation of the averaged Green function of chromophore aggregates. Consequently, thermal and static effects upon the aggregate's absorption bandshape are incorporated in terms of the correction shift of the individual chromophore's bandshapes. The utility of the theoretical formulation is shown by an illustrative calculation of the absorption bandshape of a model dimer.     

Enhancement of the synthesis efficiency of carbon cluster ions by the irradiation of two laser pulses to polymers in vacuum

We investigated the effect of the pre-irradiation of a polymer target in vacuum, using a low-fluence laser pulse, on the synthesis efficiency of carbon cluster ions ejected by laser ablation. A polymer target was irradiated by two laser pulses. The first laser was used for the pre-irradiation, and the second laser was used for ablation. The masses of the ions in the ablation plume were analyzed by time-of-flight mass spectrometry. It was found that the synthesis efficiency of carbon cluster ions was enhanced by the pre-irradiation. The effects of the fluence of the pre-irradiation, the wavelengths of the lasers, and the interval between the oscillations of the two laser pulses on the enhancement of the cluster synthesis are reported. PACS 52.38.Mf; 81.07.-b; 36.40.-c; 61.46.+w     

Composition Triple Systems and Realization of Triple Products in Terms of Bilinear Algebras

We give a definition of new triple systems and study the correspondence between triple and bilinear products for many triple systems.     

An application of the 1/Z expansion method to reorganization corrections of the Koopmans ionization energy of atomic valence state

Using the 1/Z expansion method coupled with the random spin vector model, the reorganization corrections of the Koopmans ionization energies of the atomic valence state whose spatial quantization is referred to the cartesian coordinate system were formulated up to the second order. The theoretical formulations were applied to the valence electron ionizations of s²x², s²xy and sxyz isoelectronic series. The reorganization corrections calculated with the resolvent expansion were in fairly good agreement with the corresponding terms calculated with the direct ΔSCF method using the analytical approximations to the Hartree—Fock atomic orbitals.     

Dynamic perturbation effects upon the circular dichroism intensity induced in an aggregate of dye chromophores bound to biopolymers

The dynamic perturbation effects of polarizable monomer perturbers upon the circular dichroism intensity arising from absorption transitions of an arbitrary aggregate of dye chromophores bound to a large host polymer are formulated using the linear response theory in the decorrelation approximation, where the interchromophoric retardation phase factors are eliminated by a first-order Taylor expansion which is compatible with the use of the retarded helix selection rules in the long-wavelength approximation. A space-averaged and closed-form formulation of the non-conservative circular dichroism intensity which is perturbed by intensity with the outside perturber transitions is derived in the limit of the weak dynamic perturbation where perturber—perturber interactions are negligible. The relevant formulation is applied in order to investigate the intercalation model dependence of the non-conservative circular dichroism intensity induced at the visible absorption band of proflavine molecules intercalated in either poly(A—T) or poly(G—C).     

Dilation of polyethylene by sorption of carbon dioxide

The dilation of low-density polyethylene accompanied by the sorption of CO₂ was measured by microscopy under pressures up to 50 atm at temperatures from 25 to 55°C. The dilatometry measurement, which is also applied to the determination of the thermal expansion coefficient, is directly performed by a cathetometer. The dilation of LDPE by sorbed CO₂ is linear with concentration. The buoyancy correction is described for the CO₂ sorption isotherms in LDPE. The partial molar volume of CO₂ in LDPE, calculated from the dilation and the sorption isotherms, is almost independent of temperature.     

Synthetic macrocyclic ligands. IV. Lithium ion-characteristic coloration of a “crowned” dinitrophenylazophenol

A “crowned” dinitrophenylazophenol shows a characteristic coloration only with lithium ion of alkali metal ions, as if an indicator.