Sorption and partial molar volumes of C2 and C3 hydrocarbons in polypropylene copolymers

The sorption of C₂ and C₃ hydrocarbons in two ethylene–propylene copolymers and a propylene homopolymer and the simultaneous dilation of the polymers were measured at temperatures of 287–363 K and pressures up to 4 MPa. The sorption isotherms were well described by the Flory–Huggins theory of dissolution. Dilation isotherms in the form of elongation versus pressure were similar in shape to the corresponding sorption isotherms. Solubility coefficients, partial molar volumes, and Flory–Huggins interaction parameters were determined from these isotherms. The thermal expansivities of the hydrocarbons dissolved in the polymers were 0.002–0.005 K^?1, and the Flory–Huggins interaction parameters depended not only on temperature but also on concentration. At 323 K, the calculated solubilities of propylene in the ethylene–propylene‐rubber regions of the copolymers were 1.8 times higher than in the amorphous regions of the propylene homopolymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1255–1262, 2001     

Fundamental imaging properties of transillumination laser computed tomography based on coherent detection imaging method.

The coherent detection imaging (CDI) method uses the optical heterodyne detection technique. CW and single frequency lasers having long coherence lengths are used to exploit the maximum advantages of heterodyne detection, such as high directionality, selectivity and sensitivity. The CDI method based on optical heterodyne detection enables selective filtering of the directional coherence-retaining emergent photons, which leads to image reconstruction from projections, similar to X-ray computed tomography (CT). So far we have demonstrated the advantages and capabilities of the measurement technique for transillumination optical computed tomography in biomedicine. Here, we investigate the fundamental imaging properties of CDI method, such as its high directionality and quantitativeness, with preliminary physical phantom experiments. The results show that the CDI method satisfies the requirements for CT reconstruction under the first order approximation, and enables quantitative measurements in the sense that the relationship between estimated and actual concentration retains a satisfactory linearity.     

Electron transport membrane: Preparation of polypeptide membrane with spacers between the polymer matrix and viologen moiety and their application to an electron transfer reaction

Polypeptide membranes with several lengths of spacers [? (CH₂)_n? ; n = 3, 6, 12] between the polymer matrix and viologen moiety as a functional group were prepared. Reduction of K₃Fe(CN)₆ with Na₂S₂O₄ across the obtained membrane in aqueous media were carried out and reduction rate of K₃Fe(CN)₆ across the membrane of n = 6 was faster than that of n = 3. However, the reduction of the membrane (n = 12) did not proceed chemically and electrochemically at all.     

An application of fragment interaction analysis based on local MP2

We have developed a method named ‘fragment interaction analysis based on local MP2’ (abbreviated as FILM). This method enables us to decompose the interaction energy associated with dispersion interactions into contributions of localized occupied orbitals. In this study, the basis set dependence of the results derived from FILM was examined. The results suggested that the individual ratio of pair correlation energies of selected orbital pairs to the total dispersion interaction was almost independent of the basis set size. As an illustrative example, detailed analysis was performed on the human immunodeficiency virus type 1 protease complexed with lopinavir molecule.     

Binary 1,4-asymmetric induction from a single allyltin reagent with a chiral nitrogen functional group toward aldehydes

Using a single allyltin reagent with a chiral nitrogen functionality, binary and remote asymmetric induction was realized toward various aldehydes. Either syn- or anti-1,4-amino-alcohols were selectively obtained with the use of Yb(OTf)₃ or SnCl₄, respectively. The structures of both diastereomers were identified by means of X-ray analysis.     

Orientational relationship among main and side chains of a polyimide alignment layer, liquid crystals monolayer and bulk pretilt angle

We have determined the orientational distribution of cyano-substituted side chains of a rubbed polyimide film, and a liquid crystal monolayer adsorbed on the film, by means of optical second harmonic generation. With the orientational distribution of a main chain that was measured in a previous study by means of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, we have obtained the correlation of all the orientational distributions contributing to the alignment of LC molecules, i.e. pretilt angle. We find that the side chain plays a role in increasing the pretilt angle, but in the case of rubbing strength dependence, the main chain has stronger correlation with the pretilt angle than has the side chain.