Nucleon spin structure in a relativistic constituent quark model

The spin structure of the nucleon is analyzed using a relativistic constituent quark model in light-front formulation. We investigate, in particular, relativistic effects on the axial vector coupling constants. Electromagnetic and axial form factors are constructed in terms of quark form factors that reflect the possible non-trivial structure of the constituent quarks. We study the influence of flavour mixing effects on axial constants and discuss the extent to which such effects can renormalize the singlet axial constant g _A ⁰ from its SU(6) quark model value.     

Controlled assembly of silica microspheres in spherically confined polymer particles by using self-organized precipitation (SORP) method

Assembly of submicron-sized microspheres has received much attention due to its high potential for wide variety of applications. We have developed a preparation method of polymer particles by simple mixing of a poor solvent into the polymer solution followed by evaporation of a good solvent. By using this technique, silica nanoparticles and polymer composite particles were prepared. Preparation of three-dimensional assemblies of silica particles in polymer particles and composite Janus particles are shown.     

Multipod structures of lamellae‐forming diblock copolymers in three‐dimensional confinement spaces: Experimental observation and computer simulation

The three‐dimensional (3D) confinement effect on the microphase‐separated structure of a diblock copolymer was investigated both experimentally and computationally. Block copolymer nanoparticles were prepared by adding a poor solvent into a block copolymer solution and subsequently evaporating the good solvent. The 3D structures of the nanoparticles were quantitatively determined with transmission electron microtomography (TEMT). TEMT observations revealed that various complex structures, including tennis‐ball, mushroom‐like, and multipod structures, were formed in the 3D confinement. Detailed structural analysis, showed that one block of the diblock copolymer slightly prefers to segregate into the particle surface compared with the other block. The observed structures were further elaborated using cell dynamics computer simulation. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1702–1709     

One-pot synthesis of blue light-emitting Au nanoclusters and formation of photo-patternable composite films

Blue light-emitting Au nanoclusters were synthesized in a simple one-pot process via reflux of Au ions with amino-terminated poly(1,2-butadiene) in toluene. DLS results and photoemission spectra showed that Au(8) nanoclusters were successfully formed. Moreover, photo-patterned films containing Au(8) clusters were prepared by photolithography.     

Direct Observation of Dye-Containing Amphiphilic Copolymer in the Honeycomb-Patterned Film

Honeycomb-patterned film was prepared by casting chloroform solution of hydrophobic polymer and dye-containing amphiphilic copolymer under humid conditions. The confocal laser scanning microscopy image shows that amphiphilic copolymer is localized around the pores of the honeycomb-patterned film.     

Breath Figures of Nanoscale Bricks: A Universal Method for Creating Hierarchic Porous Materials from Inorganic Nanoparticles Stabilized with Mussel‐Inspired Copolymers

High‐performance catalysts and photovoltaics are required for building an environmentally sustainable society. Because catalytic and photovoltaic reactions occur at the interfaces between reactants and surfaces, the chemical, physical, and structural properties of interfaces have been the focus of much research. To improve the performance of these materials further, inorganic porous materials with hierarchic porous architectures have been fabricated. The breath figure technique allows preparing porous films by using water droplets as templates. In this study, a valuable preparation method for hierarchic porous inorganic materials is shown. Hierarchic porous materials are prepared from surface‐coated inorganic nanoparticles with amphiphilic copolymers having catechol moieties followed by sintering. Micron‐scale pores are prepared by using water droplets as templates, and nanoscale pores are formed between the nanoparticles. The fabrication method allows the preparation of hierarchic porous films from inorganic nanoparticles of various shapes and materials.

     

Mesoscale pincushions, microrings, and microdots prepared by heating and peeling of self-organized honeycomb-patterned films deposited on a solid substrate

We describe here a preparation of pincushion structures with holes, hexagonally arranged microrings, and microdots by simple heating and peeling of self-organized honeycomb-patterned films. We have reported that the honeycomb-patterned films can be prepared by casting the solution of an amphiphilic polymer and a hydrophobic polymer under humid conditions. When annealing the honeycomb-patterned films prepared from an amphiphilic copolymer and poly(bisphenol A carbonate), we obtained a variety of mesoscale structures, depending on the heating temperatures. We revealed that these microstructures were formed by using the phase-separation structures in the self-organized honeycomb-patterned films. These micropatterns can be utilized for the template for microelectrodes, superhydrophobic surfaces, photonic crystals, and as a substrate for tissue engineering.