Molecular‐Complex Formation of Syndiotactic Polystyrene with Stable Radical Molecules

Summary: The formation of a molecular‐complex crystalline phase of syndiotactic polystyrene (sPS) that contains a stable nitroxide radical compound, 2,2,6,6‐tetramethylpiperidinyl‐N‐oxyl (TEMPO), is confirmed by IR and electron spin resonance (ESR) spectroscopy, X‐ray diffractometry, and thermogravimetric analysis. Through a guest exchange procedure assisted by a plasticizing agent, the original guest (chloroform) contained in the starting clathrate phase is completely replaced by TEMPO. Although the conformational regularity of the sPS helices in the resultant crystalline phase that contains TEMPO is similar to that in the starting clathrate phase, the host lattice expands in the 010 direction. The guest TEMPO molecules exhibit a significantly broadened ESR signal because of their highly concentrated state in the complex crystalline phase.

Thermogravimetric measurement of a powder sample of the sPS/TEMPO complex.     

3D Nanometer‐Scale Study of Coexisting Bicontinuous Morphologies in a Block Copolymer/Homopolymer Blend

Summary: Coexisting bicontinuous morphologies, one ordered and one disordered, are investigated in a macrophase‐separated poly(styrene‐block‐isoprene) diblock copolymer/homopolystyrene (SI/hS) blend. Two‐phase behavior is attributed to the relatively high hS/S mass ratio (0.92). According to its crystallographic signature and channel coordination as discerned from three‐dimensional (3D) images generated by transmission electron microtomography (TEMT), the ordered morphology is classified as gyroid. The 3D local and global topological characteristics of both bicontinuous morphologies as measured directly from TEMT images are reported. The disordered morphology is further compared with molecular‐field simulations to ascertain the spatial distribution of the constituent species within the blend, thereby demonstrating the utility of high‐resolution 3D imaging coupled with molecular‐level simulations.

     

Ultraviolet-visible and Surface-enhanced Raman Scattering Spectroscopy Studies on Ruthenium Phthalocyanine Monolayer Films Formed on Terephthalonitrile-modified Silver Substrates

A self-assembled monolayer film(SAM) of ruthenium phthalocyanine (RuPe) fabricated on a silver sub-strate premodified with an SAM of terephthalonitrile (TPN) was studied by means of surface-enhanced Ra-man seattering(SERS) and ultraviolet-visible (UV-Vis) speetroseopies. TPN was used as a ligand to linkRuPe since it can not only modify the silver suhstrate but also deliver the nitrile groups protruding from thesilver surface. Therefore, we can explore the relationship between the structure and the orientation of RuPeand the TPN-modified substrate. The UV-Vis spectra indicate a strong interaction between RuPe and TPN inthe composite film. The result is further confirmed by the SERS spectra of RuPe-TPN SAM, in which the vi-brational bands arising from both the RuPe and TPN moieties appear clearly, indicating that the RuPe is suc-cessfully assembled on the TPN film.     

Hyperbolic knots spanning accidental Seifert surfaces of arbitrarily high genus

A method for constructing hyperbolic knots each of which bounds accidental incompressible Seifert surfaces of arbitrarily high genus is given. Mathematics Subject Classification (2000):57N10, 57M25.The author was supported in part by Research Fellowships of the Japan Society for the Promotion of Science for Young Scientists.     

Demonstration of a recombined Fabry-Perot-Michelson interferometer with suspended mirrors

We describe preliminary experimental results concerning the operation of a 3 m arm-length Michelson interferometer with two Fabry-Perot cavities whose mirrors and beam splitter are suspended independently by wires. The reflected light beams from the two Fabry-Perot cavities are recombined to obtain interference at a photo-detector; this scheme is necessary for future power-recycled laser interferometers used to detect gravitational waves. The fundamental properties of the interferometer are presented, including the power spectral density of the displacement noise.     

Laser-Diode Phase-Shifting Joint-Transform Correlator with Multiple-Object Recognition

A joint-transform phase correlation is made by an extracted phase from the joint power spectrum using a phase-shifting Mach-Zehnder interferometer with a wavelength-shifted laser diode (LD), and then by numerically Fourier-transforming a measured phase. The algorithm in six steps is insensitive to the power changes in an LD. The phase correlator gives the best discrimination performance. Discriminative multiple-object recognition is performed with no intermodulation noise and artifact noise-free correlation by arranging the multiple objects in a regularly equal-spaced array. The experimental and numerical results are shown.     

Spontaneous polymerization mechanism of electron‐accepting substituted quinodimethane with vinyl ether and cyclic ketene acetal

The spontaneous reactions of 1‐(2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione‐5‐ylidene)‐4‐(dicyanomethylene)‐2,5‐cyclohexadiene (QM‐1) with a vinyl ether, butyl vinyl ether (BVE), and a cyclic ketene acetal, 2‐methylene‐1,3‐dioxepane (MDOP), were investigated. The reaction of QM‐1 with BVE produced a terpolymer composed of QM‐1, 7‐butoxy‐8,8‐dicyanoquinodimethane, and BVE units as a hexane‐insoluble product and a one‐to‐one adduct of methylene Meldrum's acid and BVE as a hexane‐soluble product. The spontaneous reaction of QM‐1 with BVE produced, in the presence of 2,2,6,6‐tetramethylpiperidine‐1‐oxy (TEMPO), a terpolymer carrying TEMPO units in the chain ends, and in the presence of methanol, a one‐to‐one‐to‐one adduct of QM‐1, BVE, and methanol was isolated. The spontaneous reaction with bulkier, electron‐donating MDOP produced a low‐molecular‐weight alternating cooligomer of QM‐1 with MDOP. The spontaneous polymerization was proposed to proceed via a zwitterionic intermediate taking two forms, gauche and trans, depending on the bulkiness of the comonomer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3800–3811, 2004     

Chemical release control: Sulfonate esters from perfume and herbicide alcohols and p-styrenesulfonyl chloride

p-Styrenesulfonate esters of primary and secondary perfume alcohols and phenols, including citronellol, 1-menthol, borneol, β-phenethyl alcohol, eugenol, p-anisyl alcohol, cinnamyl alcohol, and geraniol, and herbicide alcohols such as 2,4-dichloro- and 2,4,5-trichlorophenoxy-ethanols were synthesized using p-styrenesulfonyl chloride in the presence of bases such as pyridine, triethylamine, sodium hydrogen carbonate, and sodium hydride. The hydrolytic behavior of sulfonate ester monomers and their copolymers with N-vinyl-2-pyrrolidone to liberate perfume and herbicide alcohols was structure-dependent, thereby affording chemical release control.     

Nondestructive discrimination of ivories and prediction of their specific gravity by Fourier-transform Raman spectroscopy and chemometrics

Fourier-transform (FF) Raman spectroscopy and chemometrics were used for nondestructive analysis of ivories. The discrimination of five kinds of ivories, two subspecies of African elephant, mammoth, hippopotamus, and sperm whale, was investigated, and a calibration model for predicting their specific gravity was developed. FT-Raman spectra were measured in situ for them and chemometrics analyses were carried out for the 3050-350 cm(-1) region. The five kinds of ivories were clearly discriminated from each other on the scores plots of two or three principal components (PCs) obtained by principal component analysis (PCA). The loadings plot for PC 1 shows that the discrimination relies on the content ratio of organic collagenous protein and inorganic hydroxyapatite of ivories. The loadings plot for PC 2 shows that bands due to the CH3 and CH2 stretching modes of the protein also play a role in the discrimination. Using partial least squares regression (PLSR), we developed a calibration model that predicts the specific gravity of the ivories from the FT-Raman spectra. The correlation coefficient and root mean square error of cross validation (RMSECV) of this model were 0.980 and 0.024, respectively.