Noboru Nishioka

Formation of Metal Nanoparticles on the Surface of Polymer Particles Incorporating Polysilane by UV Irradiation

Polystyrene particles incorporating poly(methylphenylsilane) (PMPS) were synthesized by miniemulsion polymerization. UV irradiation of the emulsion under air in the presence of metal salts such as HAuCl4.4H2O, AgNO3, and Na2PdCl4 led to the formation of metal nanoparticles on the surface of polymer particles; thus, metal nanoparticle/polymer hybrid particles were obtained. The structures of the hybrid particles were confirmed by the surface plasmon resonance band and transmission electron microscopy images. The formation of metal nanoparticles depended on the functional groups and charge on the surface of the polymer particle. The metal nanoparticles were formed due to the reduction of metal ions, accompanied by the oxidation of PMPS. The interaction between the surface of the polymer particle and the metal ions plays an important role in the formation of the metal nanoparticle.

Permeability through cellulose membranes grafted with vinyl monomers in a homogeneous system: 5.2-hydroxyethyl methacrylate grafted cellulose membranes

Abstract The homogeneous grafting of 2-hydroxyethyl methacrylate (HEMA) onto cellulose was carried out in a dimethyl sulphoxide (DMSO)-paraformaldehyde solvent system. Three kinds of membranes were prepared: membranes of graft copolymers using ammonium persulphate (APS) as an initiator, membranes of graft copolymers using azobisisobutyronitrile (AIBN), and blended membranes of cellulose and poly(2-hydroxyethyl methacrylate). The diffusive permeabilities of solutes through the membranes, the states of water in them, and their microphase separated structures were investigated. Permeability through the APS and AIBN membranes was better than that through the membrane cast from the DMSO solution of cellulose. The states of water in the membranes were influenced by grafting HEMA onto cellulose. The fine microphase separated structure was essential for the improvement of the permeability through the membranes.

Thermal decomposition behavior of miscible cellulose/synthetic polymer blends

The thermal decomposition behavior of the miscible cellulosic blends cellulose(Cell)/poly(N-vinyl-2-pyrrolidone) (PVP), Cell/poly(ethylene glycol) (PEG), and Cell/poly(vinyl alcohol) (PVA) was investigated by thermogravimetry. The thermal stability of Cell in the Cell/PVP blends decreased but that of Cell in the Cell/PEG and Cell/PVA blends was hardly influenced. The thermal stability of synthetic polymers in the blends was little affected. The difference in thermal decomposition behavior was correlated to the difference in miscibility.

Preparation and Electric Property of Polysilsesquioxane Thin Films Incorporating Carbazole Groups

New silsesquioxane incorporating a carbazole groups (PCTSQ) has been synthesized by a click thiol-ene reaction and a subsequent sol-gel reaction. To evaluate the electric property of this hybrid, diode devices have been fabricated by using PCTSQ thin film by spin-coating onto n-type ZnO film prepared by the electrodeposition method. The thin film hybrid devices showed good electric characteristics and high rectification ratio, as well as worked as a rectifier.