Formation of Hierarchical Lamellae‐in‐Lamella Nanostructures from Polymer Blends Via Controlled Nonequilibrium Freezing

The creation of hierarchical nanostructures in polymeric materials has been intensively studied due to the great potential to tailor their physicochemical properties. Although much success has been achieved over the past decades in block copolymers, hierarchical structure engineering in polymer blends remains a great challenge. Here, the formation of hierarchical lamellae‐in‐lamella nanostructures from polymer blends via controlled nonequilibrium freezing is reported. Polymer blends are first dissolved in molten hexamethylbenzene (HMB) to form a homogeneous melt. When cooled to below its melting temperature, the HMB is crystallized and depleted, and the polymers are directionally solidified. This process is rapid enough that phase separation of the polymer blends is kinetically trapped at the nanoscale level. Then, the polymer blend epitaxially crystallizes onto the HMB inside the nanophase, resulting in the hierarchical lamellae‐in‐lamella structure. This structure is stable under ambient conditions and tunable depending on the annealing temperature and blending ratio.

     

High-Affinity Ratiometric Fluorescence Probe Based on 6-Amino-2,2′-Bipyridine Scaffold for Endogenous Zn2+ and Its Application to Living Cells

Zinc is an essential trace element involved in many biological activities; however, its functions are not fully understood. To elucidate the role of endogenous labile Zn²⁺, we developed a novel ratiometric fluorescence probe, 5-(4-methoxyphenyl)-4-(methylsulfanyl)-[2,2′-bipyridin]-6-amine (6 (rBpyZ)) based on the 6-amino-2,2′-bipyridine scaffold, which acts as both the chelating agent for Zn²⁺ and the fluorescent moiety. The methoxy group acted as an electron donor, enabling the intramolecular charge transfer state of 6 (rBpyZ), and a ratiometric fluorescence response consisting of a decrease at the emission wavelength of 438 nm and a corresponding increase at the emission wavelength of 465 nm was observed. The ratiometric probe 6 (rBpyZ) exhibited a nanomolar-level dissociation constant (K_d = 0.77 nM), a large Stokes shift (139 nm), and an excellent detection limit (0.10 nM) under physiological conditions. Moreover, fluorescence imaging using A549 human lung adenocarcinoma cells revealed that 6 (rBpyZ) had good cell membrane permeability and could clearly visualize endogenous labile Zn²⁺. These results suggest that the ratiometric fluorescence probe 6 (rBpyZ) has considerable potential as a valuable tool for understanding the role of Zn²⁺ in living systems.     

Globally Convergent Broyden-Like Methods for Semismooth Equations and Applications to VIP, NCP and MCP

In this paper, we propose a general smoothing Broyden-like quasi-Newton method for solving a class of nonsmooth equations. Under appropriate conditions, the proposed method converges to a solution of the equation globally and superlinearly. In particular, the proposed method provides the possibility of developing a quasi-Newton method that enjoys superlinear convergence even if strict complementarity fails to hold. We pay particular attention to semismooth equations arising from nonlinear complementarity problems, mixed complementarity problems and variational inequality problems. We show that under certain conditions, the related methods based on the perturbed Fischer–Burmeister function, Chen–Harker–Kanzow–Smale smoothing function and the Gabriel–Moré class of smoothing functions converge globally and superlinearly.     

Effects of hydrophobic chain length on the characteristics of the micelles of octaoxyethylene tetradecyl C(14)E(8), hexadecyl C(16)E(8), and octadecyl C(18)E(8) ethers

Size, shape, and flexibility of micelles of octaoxyethylene tetradecyl C(14)E(8), hexadecyl C(16)E(8), and octadecyl C(18)E(8) ethers in dilute aqueous solutions were determined at finite surfactant concentrations c by static light scattering (SLS) and dynamic light scattering experiments at several temperatures T below the critical points. The SLS results were successfully analyzed with the aid of the thermodynamic theory formulated with wormlike spherocylinder model for SLS of micelle solutions. The analysis yielded the molar mass M(w) of the micelles as a function of c and the cross-sectional diameter d. The hydrodynamic radius R(H) and the radius of gyration S(2)(1/2) of the micelles as functions of M(w) were found to be also well-described by the corresponding theories for the wormlike spherocylinder or wormlike chain models. The results of the stiffness parameter lambda(-1) have revealed that the micelles are far from rigid rods but rather stiff compared with typical flexible polymers and they grow in size with increasing T to greater length for longer hydrophobic chains, i.e., alkyl groups of the surfactants. As the alkyl group becomes longer, the d value increased, while the spacings s between adjacent hexaoxyethylene chains on the micellar surface were found to remain substantially constant.     

Dienyl homoallyl alcohols via palladium catalyzed ene-type reaction of aldehydes with 1,3-dienes

The combination of Pd catalyst and Xantphos ligand in the presence of Et(3)B nicely promotes the allylation of aldehydes with conjugated dienes to provide dienyl homoallyl alcohols in excellent yields. The reaction occurs selectively at the C-C double bond bearing higher electron density.     

A versatile scaffold for facile synthesis of fluorescent cyano-substituted stilbenes

Here we report the facile derivatization of a cyano-substituted stilbene into higher π-extended analogues. The cyano-substituted stilbene, which serves as a synthetic scaffold, has a bromo group and a formyl group on its 4- and 4′-position of the phenylene rings and thus readily undergoes selective transformation into other functional groups using various simple organic reactions. The resultant π-conjugated molecules that contain a cyano-substituted stilbene skeleton exhibit fluorescence in solution and in the solid state.     

Mechanism and elimination of interferences in flame photometry

Summary The mechanism of the suppressing effects of aluminium, borate, phosphate, sulphate upon calcium radiation has been investigated. A very stable long flame was used with a specially designed Meker Burner. Variations in the interferences were observed when Ca and those interfering substances were separately atomized into one and same flame, and also when the point in the flame from which the light was drawn was changed by the use of a specially designed optical system attached to a Hitachi-EPU-2 A spectrophotometer. It is concluded that the suppression of Ca radiation is caused by hindering of the vaporization process because of the formation of non-volatile compounds of Ca with those interfering substances.A method of eliminating the suppressing effects of borate, phosphate and sulphate on alkaline earth radiations has been suggested.

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Zusammenfassung Die durch Aluminium, Borat, Phosphat und Sulfat hervorgerufene Intensitätsminderung der durch Calcium bedingten Flammenfärbung wurde untersucht. Bin besonders konstruierter Meker-Brenner wurde zur Erzeugung einer sehr konstanten und langen Flamme verwendet. Versprüht man das Calcium und die erwähnten Störstoffe in dieselbe Flamme oder wechselt man die zur Lichtmessung gewählte Flammenregion unter Verwendung eines dafür geeigneten, an einem Hitachi-EPU-2 A-Spektrophotometer angebrachten optischen Systems, so zeigen sich jeweils verschieden starke Störungen. Daraus ergibt sich, daß die Unterdrückung der Calcium-Strahlung durch eine Beeinträchtigung des Verdampfungsvorganges infolge Bildung nichtflüchtiger Verbindungen verursacht wird, die sich aus Calcium und den angeführten Störstoffen bilden.Ein Verfahren zur Beseitigung des durch Borat, Phosphat und Sulfat herbeigeführten Unterdrückungseffektes auf alkalische Erden wurde vorgeschlagen.

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Résumé Recherche sur le mécanisme des effets de suppression de l'aluminium, des borates, des phosphates, des sulfates sur la radiation du calcium. A cette fin, l'auteur a employé une flamme longue, trés stable d'un brûleur Meker spécialement prévu. Des variations de ces effets ont pu être constatées lorsque le calcium et les substances gênantes étaient atomisés séparément dans un flamme unique et lorsqu'on faisait varier le point de la flamme émetteur de la lumière observée; ces mesures ont été rendues possibles par l'emploi d'un système optique spécialement conçu fixé à un spectrophotomètre Hitachi-EPU-2 A. La conclusion de ce travail est que la suppression de la radiation du calcium est dûe à un processus d'empêchement de la vaporisation inhérent, à la formation de composés non volatils du calcium avec les substances gênantes.L'auteur suggère une méthode permettant l'élimination des effets de suppression des borates, des phosphates et des sulfates sur les radiations des alcalino-terreux.

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This work was precented before The Eleventh Annual Meeting of The Chemical Society of Japan, in Tokyo, April, 1958.