Rapid sphere-to-prism (STP) transformation of silver was studied in aqueous AgNO(3)/NaBH(4)/polyvinylpyrrolidone (PVP)/trisodium citrate (Na(3)CA)/H(2)O(2) solutions by monitoring time-dependent surface plasmon resonance (SPR) bands in the UV-vis region, by examining transmission electron microscopic (TEM) images, and by analyzing emitted gases during fast reaction. Roles of PVP, Na(3)CA, and H(2)O(2) were studied without addition of a reagent, with different timing of each reagent's addition, and with addition of H(2)O(2) to mixtures of spheres and prisms. Results show that prisms can be prepared without addition of PVP, although it is useful to synthesize smaller monodispersed prisms. A new important role of citrate found in this study, besides a known role as a protecting agent of {111} facets of plates, is an assistive agent for shape-selective oxidative etching of Ag nanoparticles by H(2)O(2). The covering of Ag nanoparticles with carboxylate groups is necessary to initiate rapid STP transformation by premixing citrate before H(2)O(2) addition. Based on our data, rapid prism formation starts from the consumption of spherical Ag particles because of shape-selective oxidative etching by H(2)O(2). Oxidative etching of spherical particles by H(2)O(2) is faster than that of prisms. Therefore, spherical particles are selectively etched and dissolved, leaving only seeds of prisms to grow into triangular prisms. When pentagonal Ag nanorods and a mixture of cubes and bipyramids were used as sources of prisms, rod-to-prism (RTP), cube-to-prism (CTP), and bipyramid-to-prism (BTP) transformations were observed in Ag nanocrystals/NaBH(4)/PVP/Na(3)CA/H(2)O(2) solutions. Shape-selective oxidative etching of rods was confirmed using flag-type Ag nanostructures consisting of a triangular plate and a side rod. These data provide useful information for the size-controlled synthesis of triangular Ag prisms, from various Ag nanostructures and using a chemical reduction method, having surface plasmon resonance (SPR) bands at a desired wavelength.

Formation of two-and three-dimensional micro architectures with chemical functions was verified by photo-vapor phase assisted surface polymerization (VASP) of functional monomer vapors combined with an auto-drawing system manipulated by prescribed programs. The surface modification by the photo-VASP of styrene vapor progressed rapidly, and a fine lines-pattern of photo-mask was transcribed as the corresponding polymer accumulations on poly(methyl methacrylate) (PMMA) substrate surfaces. Substrate surface modified by photo-VASP of acrylic acid showed reversible changes in hydrophilic/hydrophobic properties according to repeating external chemical stimuli. The successive auto-drawing by photo-VASP of three kinds of monomer vapors was examined under spot illumination from a fine optical fiber on an X-Y stage manipulated by a prescribed program, resulting in the production of a pre-designed functional structure by successful accumulations of corresponding polymers on the substrate surface.

In order to achieve the effective interface bonding between biomass microfiller and commodity plastics, consecutive copolymerization of hydrophilic acrylic acid (AA) and hydrophobic butyl acrylate (BA) using vapor-phase assisted surface polymerization (VASP) technology was applied to prepare microcomposites consisting of cellulose microcrystal (ClC) and polypropylene (PP). After the copolymerization by VASP, ClC surfaces were covered by accumulated polymers: P(AA-co-BA) including block-type copolymer and homopolymers of 6.2-25.3 wt % versus ClC. Although structures of the products were unspecified, it was expected to be mixtures of block copolymers and homopolymers. Subsequently prepared P(AA-co-BA) on ClC/PP (5/95 wt/wt) composites expressed a superior mechanical toughness, which had increased threefold when compared to intact ClC/PP composite. This increase in toughness was mainly based on an increase in elongation rate, reflecting improvement of the adhesion strength at the interface between ClC surface and PP. The trace amounts: 0.31 wt % of accumulated P(AA-co-BA) on ClC surface must function as an effective adhesive/compatibilizer at the interface.