Mechanisms of orientational and photoelastic birefringence generation of methacrylates for the design of zero–zero‐birefringence polymers

The intrinsic birefringence Δn⁰ and photoelastic coefficient C of poly(methyl methacrylate), poly(2,2,2‐trifluroethyl methacrylate), poly(phenyl methacrylate), and poly(2,2,3,3,3‐pentafluorophenyl methacrylate) were determined. We categorized these methacrylate polymers into four birefringence‐types, even though their molecular structures differed only by the substituents on the side chains. Based on the results of Δn⁰ and C, novel polymers that exhibit neither orientational nor photoelastic birefringence, i.e., zero–zero‐birefringence polymers, were designed and synthesized by quaternary copolymerization system. Furthermore, we confirmed that the mechanisms of orientational birefringence and photoelastic birefringence generation were different in these methacrylate polymers. The conformation of the repeat unit of the polymers was nearly constant during the generation of orientational birefringence. In contrast, the conformation of the repeat unit of the polymers changed during the generation of photoelastic birefringence in the glassy state. These findings demonstrated the reasonability of evaluating orientational and photoelastic birefringence separately, as well as the adequacy of the classification of polymers into four birefringence‐types. Given these results and the fact that zero–zero‐birefringence polymers could be prepared successfully by four‐birefringence type monomers, we demonstrated the reasonability of the method for designing the zero–zero‐birefringence polymers. POLYM. ENG. SCI., 55:1330–1338, 2015. © 2015 Society of Plastics Engineers     

Hydrophilic polycarbonate chips for generation of oil-in-water (O/W) and water-in-oil-in-water (W/O/W) emulsions

Modification of the surfaces of polycarbonate (PC) with the use of a solution of tin (II) chloride renders them hydrophilic. The surface draping is stable against exposure to water and to alcohols. Exposure to alkanes reduces but does not diminish the effect. The method is compatible—in using the same solvent and temperature—with the hydrophobic modification of PC (Jankowski et al. in Lab Chip 11:1151–1156, 2011). The combination of these methods makes it possible to generate single and multiple monodisperse emulsions with the use of flow-focusing junctions in systems made in PC—a material that is suitable for fabrication of multilayer, high-throughput microfluidic devices.     

Hydrophilic polycarbonate chips for generation of oil-in-water (O/W) and water-in-oil-in-water (W/O/W) emulsions

Modification of the surfaces of polycarbonate (PC) with the use of a solution of tin (II) chloride renders them hydrophilic. The surface draping is stable against exposure to water and to alcohols. Exposure to alkanes reduces but does not diminish the effect. The method is compatible—in using the same solvent and temperature—with the hydrophobic modification of PC Jankowski et al. ( Lab Chip 11:748–752, 2011). The combination of these methods makes it possible to generate single and multiple monodisperse emulsions with the use of flow-focusing junctions in systems made in PC—material that is suitable for fabrication of multilayer, high throughput microfluidic devices.     

Constant-phase-mode operation of the light-addressable potentiometric sensor

The constant-phase-mode operation of the light-addressable potentiometric sensor (LAPS) is proposed and demonstrated. In this new operation mode, the temporal change and the spatial distribution of the analyte concentration are recorded in the form of the bias voltage applied to the LAPS sensor plate, which is servo-controlled to maintain the phase of the photocurrent at a constant value with respect to the light modulation. The constant-phase-mode LAPS is advantageous for its wider measurement range and reduction of artifacts.     

Damage to seagrass and seaweed beds in Matsushima Bay,Japan, caused by the huge tsunami of the Great East Japan Earthquake on 11 March 2011

Damage to seagrass and seaweed beds caused by the huge tsunami of the Great East Japan Earthquake on 11 March 2011 was investigated in Matsushima Bay, Miyagi Prefecture, Japan, by comparing satellite images taken before the tsunami in November 2009 and after the tsunami in May 2011. The results showed that the tsunami destroyed 220 ha of seagrass and seaweed beds, from 320 ha in 2009 to 100 ha just after the tsunami. Zostera marina beds on the sandy and muddy bottom were rather severely damaged compared with brown seaweed beds of Sargassum horneri on the rocky substrate. Substrates of the beds and directions of the tsunami seem to be responsible for the magnitude of the damage to the beds. Maps of the spatial distributions of the beds before and after the tsunami can provide information for the restoration of seagrass and seaweed beds as natural infrastructures of coastal fisheries resources.     

Growth and structure of heteroepitaxial thin films of homologous compounds RAO3(MO)m by reactive solid-phase epitaxy: Applicability to a variety of materials and epitaxial template layers

A reactive solid-phase epitaxy (R-SPE) method combines deposition of a thick amorphous or polycrystalline layer with a desired chemical composition and post-deposition solid-phase epitaxial growth. The solid-phase epitaxial growth is invoked by thermal annealing with an assistance of a sacrificial layer working as an epitaxial template. Thereby it enables us to grow high-quality epitaxial films of complex oxides whose epitaxial films are not grown by conventional high-temperature growth techniques. It was reported that 2-nm-thick ZnO layers worked as template for growing InGaO₃(ZnO)_m (m = integer) epitaxial films. The present study extended the R-SPE technique to growth of various complex oxides with chemical compositions of RAO₃(MO)_m and to use of various epitaxial template layers. We found that mono oxide epitaxial layers such as In₂O₃ and Ga₂O₃ work as template layers as well. Alternatively, a ZnO epitaxial layer is also applicable to ZnO-free compounds. The films obtained were grown heteroepitaxially on YSZ(111) and single-crystalline when the fabrication conditions are optimized.     

A novel bistable reflective display using quick‐response liquid powder

Abstract— We have developed new powder materials that exhibit liquid behavior, which can lead to the realization of novel bistable and reflective displays having paper‐white appearance, high contrast, and quick response. Two types of display were demonstrated, one had 160 × 160 array of pixels and the other had 320 × 320 in a 3.1‐in.‐diagonal viewable image size corresponding to 66 and 132 dpi, respectively. These displays were driven by passive‐matrix addressing. The displays showed a reflectivity of more than 41%, a contrast more than 1:10, and a pixel response time of less than 0.2 msec. The seven‐segment display for use in clocks was also demonstrated.     

Catalytic cycle of cytochrome-c3 hydrogenase,a [NiFe]-enzyme,deduced from the structures of the enzyme and the enzyme mimic

Hydrogenases catalyze uptake and production of H₂. Heterolytic cleavage of H₂ bound on [NiFe]-hydrogenase (E) produces two unequal H species to form E:H_aH_b, where H_a and H_b behave differently. The structures of various states of the enzyme established by crystallography and spectroscopy were used to construct a catalytic cycle of the enzyme. The Ni–Fe center of the active enzyme has the Ni–Fe bridging site vacant. The enzyme is suggested to bind H₂ either at Ni or Fe atom. In E:H_aH_b, H_a is considered to be a protein-bound hydron (proton or deuteron) at the entrance to the hydrophobic gas tunnel. The structure of a synthetic hydrogenase-mimic suggests H_b to be the 6th ligand to Fe. Two successive one-electron processes from E:H_aH_b complete the catalytic cycle of H₂ uptake. The reverse of the cycle operates in the H₂ production. The proposed catalytic cycle is consistent with the kinetic, crystallographic and spectroscopic studies.     

Inhibition of char deposition using a particle bed in heating section of supercritical water gasification

Supercritical water gasification (SCWG) has attracted attention as a technology for utilizing wet biomass. We used a fluidized bed of alumina particles to prevent blockage of a SCWG reactor. A glucose solution was heated in the reactor with and without fluidized alumina particles. In the absence of alumina particles, char particles formed homogeneously in the reactor, but the use of a fluidized bed resulted in accumulation of char particles at the reactor’s exit rather than inside the reactor. Therefore, the fluidized bed was effective at preventing blockage of the reactor. However, the alumina particles did not remove deposits from the reactor’s walls. Instead, the fluidized bed caused larger char particles to form, preventing their adhesion to the reactor’s wall.