Microwave‐assisted polycondensation of 4‐octylaniline with dibromoarylene

The Pd‐catalyzed polycondensation of 4‐octylaniline with various dibromoarylenes was carried out under microwave heating. Microwave heating led to a decrease in the reaction time and an increase in the molecular weight of the polymers as compared to conventional heating. Microwave heating also allowed the catalyst loading to be reduced to 1 mol %, yielding polymerization results that were comparable to those under conventional heating and 5 mol % catalyst. Investigations regarding field‐effect transistors and organic photovoltaic cells using the obtained poly(arylamine) with azobenzene units revealed that increasing the molecular weight of the polymer led to improved device performance, including hole mobility and power conversion efficiency. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 536–542     

Status of heavy element research using a gas-filled recoil separator at RIKEN

A gas-filled type of recoil separator for heavy element research was installed at an experimental hall of RIKEN Linear Accelerator facility to realize getting higher intensity of primary beam and long beam time. Performance of the separator was studied using target recoils and various nuclear reactions. The results show the high performance of the separator for heave element research. As an application of the GARIS, production and identification of an isotope of the 110th element ²⁷¹[110] have been performed using the ²⁰⁸Pb(⁶⁴Ni,1n)²⁷¹[110] reaction. Three decay chains coincide well both in decay times and energies with the ones reported by the group of SHIP experiment at GSI, Germany. Our results provide a confirmation of the synthesis of an isotope ²⁷¹[110] of element 110.     

Measurement of intense microwave field patterns using a neon glow indicator lamp

A novel method using small neon glow lamps with electrodes is developed for measuring intense microwave field patterns. When the lamp axis coincide with the electric field direction, the lamp discharge starts at the feeblest microwave electric field strength. Therefore, the lamp axis shows the field direction and the discharge starting indicates the field strength. The field strength for starting the microwave discharge is less than the strength for AC discharge, because of its low loss discharge mechanism. In the experiments using a microwave oven, it has been demonstrated again comparing with the simulated results that the method is able to use for measuring the intense electric field strength and direction.     

A novel pre-shearing technique for measurement of the electrorheological effect of a side-chain liquid crystalline polysiloxane

A side-chain liquid crystalline polysiloxane derivative possessing mesogens was synthesized. The mesogens included a large dielectrically-anisotropic moiety. Phase transition behaviour was investigated and the electrorheological (ER) effect of the polymer considered. No ER effect was observed in non-sheared polysiloxane derivative because of its high inherent viscosity. However, a large ER effect was observed after pre-shearing. Pre-shearing, i.e. shearing with a high shear rate before the measurements, arranges the terminal mesogens in the shearing direction. Furthermore, a dilution of the sample led to a larger ER effect exceeding 10 000 Pa. We thus were able to demonstrate a new approach for the appearance of the ER effect.     

Hydration Structure Around the Carboxyl Group Studied by Neutron Diffraction with 12C/13C and H/D Isotopic Substitution Methods

Time-of-Flight (TOF) neutron diffraction measurements have been carried out on aqueous 8 mol% sodium acetate solutions in D₂O. Scattering cross sections that were observed for sample solutions involving ¹²C/¹³C and H/D isotopically substituted acetate ions were used to derive the first-order difference functions, Δ_H(Q) and Δ_C(Q), and corresponding distribution functions, G _H(r;r) and G _C(r;r), which describe the environmental structure around the methyl and the carboxyl groups within the acetate ion, respectively. Structural parameters concerning the first hydration shell of the carboxyl group within the acetate ion were obtained through the least squares fit to the observed intermolecular difference function, Δ_C ^inter(Q). The nearest neighbor C _O...D _W1 (C_O: carboxyl carbon atom, D_W1: water deuterium atom) distance, r(C _O...D _W1 ), and the angle, ∠ C _O ...D _W1 -O _W (O _W : water oxygen atom), were determined to be 2.63(1) Å and 120(1)°, respectively. The coordination number, n(C _O ...D _W1 ), was obtained to be 4.0(1). These results are consistent with the hydration structure in which water molecules in the first hydration shell of the carboxyl group are hydrogen-bonded with oxygen atoms of the carboxyl group.     

Magnesium-butadiene addition compounds: Isolation,structural analysis and chemical reactivity

The magnesium-butadiene 1 : 1 (1), 1 : 2 (II) and 1 : 3 addition compounds obtained by the direct metalation of butadiene with metallic magnesium were isolated. These compounds have a polymeric structure. Structural analysis of these compounds by NMR and IR methods was carried out. The process for the formation of II via I and III via II was investigated. The results of protolysis and alkylation of the above magnesium compounds corresponded well to those of crotylmagnesium compounds.     

Preparation of Polymer Particles Coated with Hydroxyapatite

Polymer particles coated with hydroxyapatite were prepared by treating Pd0 immobilized polystyrene-co-acrylic acid particles in aqueous CaCl2 and NaH2PO2 solutions. Hydroxyapatite coating took place at neutral to alkaline pH conditions, and the homogeneous growth of the hydroxyapatite layer on the surface of polymer particles was observed at relatively low temperature (30-50 degrees C). The thickness of the hydroxyapatite layer increased with reaction time. Copyright 1999 Academic Press.     

Distribution of polymer deposition in plasma polymerization. III. Effect of discharge power

Distribution of polymer deposition in an inductively coupled rf discharge system is studied as a function of level of discharge power with acetylene and styrene as monomers. When a fixed flow rate is used, the discharge power has a relatively small effect on the pattern of distribution of polymer deposition as long as values of W/FM, where W is discharge wattage, F is flow rate, and M is molecular weight of monomer, are maintained above a critical level to maintain full glow in the reaction tube. It has been shown that plasma polymerization of two monomers which have different molecular weights can be compared in a fair manner by selecting conditions to yield similar value of W/FM.     

Plasma polymerization of tetrafluoroethylene. III. Reproducibility and effects of substrate and reactor materials

Plasma polylmerization occurs in plasmas surrounded by surfaces and polymer formation is one of the complicated interactions that take place between active species and molecules which constitute surfaces and gas phases. Effects of reactor wall, substrate materials, flow rate, and discharge power on polymer formation, and properties of polymer deposits were investigated by ESCA, IR (infrared) spectroscopy, and the measurement of system pressure. The effect of surface is important at the initial stage of plasma polymerization which can be easily detected by the system pressure change; however, integrated properties such as IR spectroscopy and the deposition rate show the effect in a less pronounced manner. ESCA, which reflects the properties of surface (approximately 20 A? in depth), showed the effect of surface in an even less sensitive manner. The amount and properties (including the effects of surfaces) are dependent on plasma polymerization parameter W/FM(W, wattage; F, volume flow rate; and M, molecualar weight of monomer) and the location of deposition within a reactor. IR and ESCA data clearly showed the dependence of polymer properties on W/FM; i.e., increase of W and decrease of M to be equivalent. When all these factors were kept under control, the reproducibility of plasma polymerization was found to be excellent.