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This study examines the roles of chemical compounds that can generate spontaneous interfacial motion, especially in the Nakache and Dupeyrat system, which normally used a stearyltrimethylammonium chloride (STA-Cl) aqueous solution and a KI + I2 nitrobenzene solution. Spontaneous behavior at the interface of a system comprising the STA-Cl aqueous solution and a nitrobenzene solution of ZnCl2 or FeCl3 was observed. To explore the mechanism, measurements of the interfacial tension, critical micelle concentration (CMC), and solubilization rate were performed for the ZnCl2 system. The aggregates produced at the oil/water interface were subjected to infrared spectroscopic analysis, and the time dependence of aggregate coverage at the interface was measured. The analyses suggested that the spontaneous changes were generated because Fe3+ and Zn2+, which have high ion-transfer potentials, could not easily move to the aqueous phase from the oil phase, and the counterion, Cl−, also remained near the interface, resulting in a reduction of the CMC and promotion of solubilization. This information affords an understanding of the kinds of materials that can be used to produce a high level of spontaneous interfacial motion and aids in the development of a spontaneous interfacial motion system not utilizing toxic substances.

Al 2 O 3 filters for CO 2 gas separation were prepared by slip casting method. Average pore size and porosity of the obtained Al 2 O 3 filters were about 74 nm and 40%, respectively. To evaluate the pore size effect, the Al 2 O 3 filters having average pore size of 760 nm were also prepared. FE-SEM micrographs show fine new crystals on the pore surface. They were synthesized by hydrothermal treatment, and were identified to AlOOH by XRD and XPS. Both gas selectivity of the filter having larger pore size were about 1, which indicated that this filter has no gas separation capability. In contrast, the gas selectivity of the Al 2 O 3 filter with 74 nm pores became about 1.47 at 0.01 MPa. The N 2 /CO 2 gas selectivity was improved by controlling the pore size and the chemical properties of a pore surface precisely and by setting an appropriate gas permeation pressure.

After a rutile powder was modified with Au, visible-light photocatalytic activity of the powders before and after sonication treatment was evaluated using the decomposition of gaseous 2-propanol (IPA) to acetone. The modified powders possessed almost identical Au concentrations, and the difference of specific surface area before and after sonication was negligible. Au nanoparticles on the surface of rutile were grown and the wavelength of the peak attributable to localized surface plasmon resonance (LSPR) by Au was red-shifted 46 nm by sonication treatment. Photocatalytic activity measurements done by changing the wavelength range of illuminated light suggest that the wavelength of sensitivity for photocatalysis using LSPR under visible light is tunable by sonication.

Effects of UV illumination on a mixture of water and a methylene blue (MB) solution in a TiO 2 -coated microchannel were investigated by changing the illuminated section. The TiO 2 coating possessed photocatalytic activity. The mixing length of the liquids increased during UV illumination of an entire microchannel. However, the length became around 20% shorter than that before UV illumination when the UV illumination section was limited at the straight portion of the microchannel. The braking effect of liquid flow at the UV–dark border probably plays an important role in this phenomenon.

Clusters of MnO x and CeO y were modified onto TiO 2 (rutile) surface by chemisorption calcination cycle processing. Then the decomposition activity on 2-naphthol in water was evaluated at 50 °C under visible light illumination or in the dark. The modification of MnO x and CeO y clusters provided decomposition activity on 2-naphthol in the dark. It was increased by visible light illumination. The decomposition activity in the dark was dependent on the reaction temperature. The synergy effect in the co-modification of these two clusters was inferred from the reaction constants. Although the activity in the dark decreased gradually through repeated use and resultant reduction of MnO x and CeO y clusters, it recovered by UV illumination and subsequent heating at 80 °C in ambient air.

Porous TiO2 sphere particles were prepared by impregnating titanium (IV) oxysulfate solutions into organic monolith particles, with subsequent calcination in air. The powder possessed pores of meso-order. Its crystalline phase was anatase. Then, 12 Tungsto(VI) phosphoric acid (PW12) was present in the mesopores. The entire surface was modified to be hydrophobic by octadecylphosphonic acid (ODP). Subsequent UV illumination in water removed the PW12 and ODP adsorbed onto the outer sphere surface. The obtained spherical TiO2 particles with hydrophobic acidic nanopores exhibited high photocatalytic performance against the removal of 1,4-dioxane in water. Detailed analysis revealed that this material removed both 1,4-dioxane and ethylene glycol diformate (EGDF), the main intermediate of the photocatalysis of 1,4-dioxane. Results suggest that hydrophobic acidic nanopores enhance adsorption of EGDF in water and play an important role in the overall photocatalytic performance of this system.

The photonic bands of various TiO2 2D photonic crystals, i.e., cylindrical, square and hexagonal columns connected with/without walls and filled with acetonitrile, were investigated from the perspective of dye-sensitized solar cells. The finite-difference time-domain methods revealed that two-dimensional (2D) photonic crystals with rods connected with walls composed of TiO2 and electrolytes had complete photonic band gaps under specific conditions. This optimally designed bandgap reaches a large Δω/ωmid value, 1.9%, in a triangular array of square rods connected with walls, which is the largest complete 2D bandgap thus far reported for a photochemical system. These discoveries would promote the photochemical applications of photonic crystals.

The spontaneous motion of a nitrobenzene droplet combined with iodine and potassium iodide on an aqueous phase containing a cationic surfactant (stearyltrimethylammonium chloride) was activated by the addition of a small amount of chlorobenzene into the droplet. The highest speed of droplet motion was observed when it was composed of 60% nitrobenzene and 40% chlorobenzene. To explore the factors affecting this activation, for the oil phase, the density and viscosity, the solubility of the surfactant and the interfacial tension of the oil/aqueous phase for various concentrations of nitrobenzene–chlorobenzene were evaluated. The aggregates produced at the oil/water interface were subjected to elemental and melting point analyses. These results were carefully compared with those of previous theoretical studies. The analyses revealed that the balance of the kinematic properties of the oil phase solution and the rate of the electrophilic substitution reaction is the most important factor contributing to the activation.

During evaporation, shape changes of nanoliter-scale (80–100 nL) water droplets were evaluated on two superhydrophobic surfaces with different random roughness (nm-coating, μm-coating). The square of the contact radius and the square of the droplet height decreased linearly with evaporation time. However, trend changes were observed at around 170 s (nm-coating) and around 150 s (μm-coating) suggesting a wetting mode transition. The calculated droplet radii for the wetting mode transition from the average roughness distance and the average roughness height of these surface structures were approximately equal to the experimental values at these trend changes. A certain level of correlation between the roughness size and droplet radius at the wetting mode transition was confirmed on surfaces with random roughness.

In this paper, thermal fusion of polymer spherical particles was examined to prepare ring structures on a solid substrate. Polystyrene particles (200 nm diameter) were two-dimensionally arrayed by an evaporation-driven method. The self-assembled structures, i.e., two-dimensional colloidal crystals, were kept under 50°C for 20 minutes. Three peeling methods were tried after the thermal fusion treatment: manual peeling, peeling by polydimethylsiloxane adhesion and mechanical peeling. We show that using these peeling methods we were able to obtain the ring structures as well as other interesting structures.

Porous ZrO2–SiO2 composite sphere particles were prepared by impregnating precursor solutions into organic monolith particles, with subsequent calcination in air. The porous spheres possessed uniformly sized pores of around 10 nm. Addition of SiO2–ZrO2 decreased the ZrO2 crystallinity and increased the specific surface area. The acid amount on the surface of the composite spheres was increased by treatment with H2SO4. The acid strength and its amount, including the Lewis/Bronsted acid ratio, depended on the SiO2/ZrO2 ratio and the H2SO4 concentration. The powder treated under an optimum condition exhibited higher solid acidity than the reference solid acid catalyst. The prepared porous SO4 2−/ZrO2–SiO2 spheres showed higher saccharization activity than the reference solid acid catalyst did.

Photoinduced surface friction variations of the polished surface of polycrystalline rutile ceramics under UV illumination in different atmospheres was evaluated using FFM. When UV was irradiated onto the rutile surface, the surface friction force first increased and then decreased. Once the water contact angle of the rutile surface reached the lower limit, the surface friction force increased gradually. Increased friction force on the surface in the early stage of UV illumination was attributable to decomposition of the surface organic contaminant and the resultant increase of surface energy from the fitting of calculated contact angles to practical values. However, the friction force decrease and gradual increase after a certain period of UV illumination are attributed to the lubrication effect and either a capillary effect or the increased adsorbed water layer by humidity control. From the force curve measurement on the highly hydrophilic rutile single crystal (1 0 0), the repulsion force was detected from 2 to 3 nm separation distance.

Four patterned surfaces with hydrophilic areas of different sizes were prepared using photolithography with a smooth octadecyltrimethoxysilane (ODS) hydrophobic coating. The hydrophilic area in the surfaces was aligned hexagonally with a constant area fraction. The sliding angle and contact angle hysteresis of the water droplets increased concomitantly with increasing pattern size. The increase of the contact line distortion between defects at the receding side plays an important role in this trend. The droplet sliding velocity also increased concomitantly with increasing pattern size. This trend was simulated by a simple flow model. The contribution of the interface between the ODS region and the hydrophilic area was deduced from this trend. This study demonstrated the different size dependency of the chemical surface defects for sliding behavior between the critical moment at which a droplet slides down and the period when a droplet is sliding.

The photonic bands of various TiO2 photonic crystals filled with acetonitrile were investigated with the perspective for application to dye-sensitized solar cells. Finite-difference time-domain methods revealed that three-dimensional (3D) photonic crystals with diamond-log and inverse-diamond-log structures composed of TiO2 and an electrolyte had full photonic band gaps under certain conditions. The quality factor of the band gap and the electrolyte filling factor of the structures were optimized. Moreover, with the consideration for easy fabrication of such photonic crystals, two-dimensional (2D) photonic crystals, i.e., TiO2 slabs with square holes filled with electrolytes, were also investigated. Two-dimensional structures that have a full photonic band gap were also discovered. These discoveries may lead to early electrochemical applications of dye-sensitized photonic-crystal electrodes.

現在の世界的な問題の一つとして，科学・技術による使用エネルギー量増加の問題が挙げられる。多くの諸国が先進国並みの技術を獲得し，場合によっては先進国を凌駕し，多くの利便性を得るとともに多くのエネルギーを消費している。本問題の解決策として注目を集めているのが自己集積・自己組織化プロセスである。本稿では，固体表面に形成される溶液の薄膜を利用して微粒子を自己集積的に二次元に配列させる手法の一つ，移流集積法について，温度・湿度ならびに物理的・化学的界面特性変化による配列の違いを紹介する。また，その配列体（二次元コロイド結晶，二次元微粒子アレイ，二次元自己集積体，粒子膜などと呼ばれている）と応用についても，ごく簡単に紹介する。

The spontaneous generation of an electric current was examined by means of a camphor boat. The camphor boat attached a small magnet was spontaneously circled around a coil in a petri dish, resulting in the generation of an induced electric current. Moving modes of the camphor boat were determined by the shape of the petri dish and the camphor boat. The angular velocity of the camphor boat was about π/sec. The influences of the distance from the coil to the magnet and of the angular velocity on the generated electricity were also examined.

The photonic energy bands of titanium dioxide (TiO2) hollow spherical arrays, which are self-assembled photonic crystals, were investigated. The finite-difference time domain (FDTD) method was applied to both the face-centred-cubic (fcc) and body-centred-cubic (bcc) packing structures of TiO2 hollow spherical arrays to determine the energy bands from the perspective of photoelectrode applications. Calculations were carried out on the basis of the TiO2 shell wall thickness. The spectral behaviour of light in the hollow spherical arrays was also studied, with particular interest devoted to the pseudogap found in one of the structures. A three-dimensional (3D) TiO2 hollow spherical array was then experimentally synthesized in three steps: the preparation of synthetic opal templates, replication by spin coating, and sintering. The diffuse scattering spectrum of the obtained array was finally measured and compared with the calculated photonic band structure.

The photonic energy bands of the inverse-opal solar cell were calculated. The finite difference time domain method was applied to the analysis of both hexagonal closest packed (hcp) and face-centered cubic (fcc) structures of the TiO 2 -electrolyte photonic crystal. The electrolyte, which filled the calculated photonic crystals, was set as an acetonitrile system. The calculated photonic energy bands were compared with the experimental scattering spectra.

Development of new self-organized preparation method of non-spherical nano or microparticles against the surface tension is a challenging and attractive field in material science. Already our research group has reported fabrication of several kinds of honeycomb-patterned microporous polymer films (“honeycomb films”) by the “self-organization” process. By use of the honeycomb films, non-spherical particles composed of a particle array assembled the polymeric spherical nanoparticles were also prepared by self-organization processes. The preparation steps of the nanoparticles-assembled particles were: (1) formation of the two-dimensional single-layered arrays of polymeric spherical nanoparticles in each micropore of a honeycomb film by means of self-assembly of the nanoparticles, (2) connection of the all contacting nanoparticles in each micropore, then (3) peeling of the nanoparticles-interconnected particles from the honeycomb-nanoparticles composite structure. Number of the nanoparticles introduced into a micropore depended on the ratio of diameter of the honeycomb micropore to that of the nanoparticles. In the prepared non-spherical particle, alignment of the spherical nanoparticles was copied from that of the two-dimensional array of the nanoparticles assembled in the honeycomb micropore.

The self-assembly preparation methods and application of two-dimensional colloidal crystals, in which fine spherical particles (15nm-20μm) are two-dimensionally periodically ordered on solid substrates, are reviewed. Among the preparation methods, evaporation-driven self-assembly, electrophoretic deposition, ink-jet printing, lift-up soft lithography are reveiwed. As examples of the applications, antireflection films, micro-lens arrays, a model of photonic crystals, and masks for lithography are introduced.

Porous Al 2 O 3 bodies, having an average pore size of approximately 74 nm and a porosity of 40.4%, were prepared by the slip-cast method. The intended porous ceramics were prepared by hydrothermal treatment of the porous Al 2 O 3 bodies. The obtained samples consisted of AlOOH and α-Al 2 O 3 phases, and the α-Al 2 O 3 surfaces were coated with AlOOH particles. The CO 2 /N 2 gas selectivities of the samples depended on the conditions of the hydrothermal treatment and were found to decrease with increasing hydrothermal treatment time. However, the gas selectivities of the samples heated for 96 h were nearly equivalent to those of the samples heated for 72 h. A high concentration of Al(NO 3 ) 3 , which was used as the aluminum source, leads to a decreased CO 2 /N 2 gas selectivity. Moreover, CO 2 /N 2 gas selectivity decreased slightly at low pressure drop. The minimum selectivity attained was approximately 0.69 at 0.02 MPa.

This paper reports the preparation of freestanding two-dimensional (2D) particle arrays, which fine particles are packed in highly dense and oriented manner. To fabricate freestanding 2D arrays, sintering process of the polymer particles (3.06, 1.034, and 0.491 μm diameter) was examined. The sintered 2D particle arrays on glass substrates were easily peeled off as a freestanding film by soaking into water. The freestanding 2D particle arrays were stable enough in room temperature. They show the iridescent colors due to their optical periodicity. To convince the layer number of those freestanding 2D particle arrays, fluorescent polystyrene particles were added in the arrays. Fluorescent light propagation patterns in the arrays suggest that the freestanding films were monolayers. The transmission spectra of the freestanding film were also examined.

Hierarchical nanoporous structures were fabricated from mesoporous silica and organic monolith with the aim of fabricating a high-efficiency catalyst carrier. The hierarchical structures were modif...

Water droplets, which were surrounded by polymers, were used as capsules to form dissipative-hierarchy structures. Such droplets were spontaneously formed on an organic solvent surface in high-humidity air. Water suspension of polystyrene particles was dropped onto the organic solvent in high-humidity air. Consequently, polystyrene particles were transferred into the water droplets, due to lateral capillary force, and formed a honeycomb structure. The size of high-hierarchy (=polymer capsules) was 1–3 μm, and the size of small-hierarchy (=polystyrene particles) was 0.05–1 μm. The results suggest the possibility that any material that can be suspended in water would form into a periodic structure by the dissipative process.

It has been known that the influenza A virus infection induces a cross-protective immunity against infection by viruses with different subtypes of viral envelope proteins, hemagglutinin and neuraminidase. This heterosubtypic immunity is generally mediated by cytotoxic T lymphocytes (CTL) reactive to specific epitopes in the viral internal proteins, such as nucleoprotein and matrix protein. By contrast, immunization with inactivated virus antigens has been thought to be unable to generate heterosubtypic immunity, since inactivated antigens do not usually induce CTL responses. However, we show that intranasal immunization with formalin-inactivated intact virus, but not ether-split vaccines, induced a broad spectrum of heterosubtypic protective immunity in mice. The protection may be mediated by the mucosal immune response, most likely secretory IgA antibodies to the viral proteins. This approach may overcome limitations in the efficacy of inactivated influenza vaccines and confer potent immunity to humans against viruses with new pandemic potential.

It has been known that influenza A virus infection induces a cross-protective immunity against infection by viruses with different subtypes of viral envelope proteins, hemagglutinin (HA) and neuraminidase (NA). This heterosubtypic immunity is generally mediated by cytotoxic T lymphocytes (CTL) reactive to specific epitopes in the viral internal proteins, such as nucleoprotein and matrix protein. By contrast, immunization with inactivated virus antigens has been thought to be unable to generate heterosubtypic immunity, since inactivated antigens do not usually induce CTL responses. However, we show that intranasal immunization with formalin-inactivated intact virus, but not ether-split vaccines, induced a broad spectrum of heterosubtypic protective immunity in mice. The protection may be mediated by the mucosal immune response, most likely secretory IgA antibodies to the viral proteins. This approach may overcome limitations in the efficacy of inactivated influenza vaccines and confer potent immunity to humans against viruses with new pandemic potential.

A new testing method for the assessment of hazardous environmental chemicals using cultured human neuronal cells has been developed. This method is based on the image analysis of the neurite extension in human neuroblastoma NB-1 cells: the length of the extended neurites was determined using image analysis software. Using this system, 255 chemicals including methylmercury and endocrine disrupting chemicals were tested. Methylmercury and several chemicals inhibited neurite extension, while cadmium chloride, phthalates, and many other chemicals promoted it. These results suggest that the extended neurite length is a useful biological marker for the effects of neurotoxic environmental chemicals, especially on the developing nervous system.

Flexible two-dimensional particle arrays, which are periodic structures in the optical region, were prepared utilized a thermosetting resin. This type of arrays can be bent easily and repeatedly. Beautiful light propagation patterns such as micro-circle or micro-star-like shapes were observed inside of flexible two-dimensional particle arrays from the emission of fluorescent particles in the arrays. This flexible two-dimensional particle array might be changed the general idea of self-assembled structures; which normally exist on solid substrates.

Highly hydrophobic surfaces with nanoscale roughness were prepared by coating two fluoroalkylsilanes (FAS17 and FAS3) respectively onto boehmite deposition layers. The droplet shape change on the s...

Defective TiO(2-x) was synthesized via a facile anodization technique. Electron paramagnetic resonance spectra confirmed the presence of oxygen vacancy, which extended the photon-absorbance deeply into the visible-light region. By stripping off the nanotubes on top, a hexagonally dimpled layer of black TiO(2-x) was exposed and exhibited remarkable photocatalytic activity.

Various smooth hydrophobic silane coatings were prepared on a Si substrate using CVD. Then adhesion and friction force for these coatings were evaluated using force curve measurements and friction ...

Photonic crystal is a frontier material to control photons. Among many photonic crystals, the inverse opal structure, which is formed by using a mold of self-assembled particles, became popular because of its easy fabrication and easy chemical modification. In this paper, the TiO2 inverse opal structure was modified to a dye-sensitized photoelectrode. The inverse opal structure was designed to inhibit the emission of the dye. As a result, the incident monochromatic photon-to-electron conversion efficiency per one molar dye of the dye-sensitized inverse opal electrode becomes larger than the one of a normal dye-sensitized electrode.

Titanium dioxide (TiO 2 ) has been draw attention for wide range of applications from photonic crystals for visible light range by its catalytic characteristics to tera-hertz range by its high refractive index. We present an experimental study of fabrication of fine structures of TiO 2 with a ZEP electron beam resist mask followed by Ti sputter deposition techniques. A TiO 2 thin layer of 150 nm thick was grown on an FTO glass substrate with a fine patterned ZEP resist mask by a conventional RF magnetron sputter method with Ti target. The deposition was carried out with argon-oxygen gases at a pressure of 5.0 x 10 -1 Pa in a chamber. During the deposition, ratio of Ar-O 2 gas was kept to the ratio of 2:1 and the deposition ratio was around 0.5 A/s to ensure enough oxygen to form TiO 2 and low temperature to avoid deformation of fine pattern of the ZPU resist mask. Deposited TiO 2 layers are white-transparent, amorphous, and those roughnesses are around 7 nm. Fabricated TiO 2 PCs have wider TiO 2 slabs of 112 nm width leaving periodic 410 x 410 nm 2 air gaps. We also studied transformation of TiO 2 layers and TiO 2 fine structures by baking at 500 °C. XRD measurement for TiO 2 shows that the amorphous TiO2 transforms to rutile and anatase forms by the baking while keeping the same profile of the fine structures. Our fabrication method can be one of a promising technique to optic devices on researches and industrial area.

The effect of the triangular pinning region on the sliding of water droplets on the smooth hydrophobic surface was investigated. Smooth hydrophobic silane coatings with various regular triangle hydrophilic regions were prepared using photolithography and octadecyltrimethoxysilane (ODS). The hydrophilic area in the surfaces was aligned hexagonally with a constant area fraction. Thereby water contact angles of the coatings were almost equivalent. The water droplet sliding velocity increased continuously with increasing pattern size. Anisotropic sliding velocity was observed on the surface, suggesting different pinning effects. The sliding motion of water droplets on the gradient surface with changing hydrophilic region size deflects against the downward direction. The deflection length depends on the direction of triangle hydrophilic regions and the initial sliding position. These results demonstrate that control of the sliding velocity while sustaining the static contact angle is feasible by designing the shape and alignment of chemical heterogeneity.

Nanohole-based biosensors are some of the most promising next generation biosensor platforms thanks to their size selectivity and position dependent sensing properties. For practical applications, large-area fabrication with properly controlled dimensions and sensor performance is essential. Here, we investigate the size controllability of hexagonally ordered plasmonic nanohole arrays produced through self-assembly of mask colloid nanoparticles, and analyzed the hole-size dependent sensor properties by electromagnetic simulations. Size-reduction of the colloids to about half of their original size is the smallest achievable hole size, which roughly corresponds to the optimal diameter for the refractive index sensing. The field enhancement tuning is also discussed.

We report a case of cerebral infarction developed either during or immediately after an operation. A 71-year-old man with esophageal cancer and a history of hypertension and asymptomatic cerebral infarction underwent right thoracolaparotomy for a subtotal esophagectomy. Anesthesia was maintained with a combination of 2% sevoflurane in oxygen and epidural analgesia using 2% mepivacaine. The operation was uneventful and the patient was transferred to ICU with the tracheal tube in place. On removal of the tracheal tube the next day the patient was unable to speak and his grip power of the right hand was weak. On CT a cerebral infarction was found in the left frontal lobe. A left carotid echogram showed a 90% constriction. The occlusion of the middle cerebral artery by an embolus detached from the constricted origin of the carotid artery was thought a most probable cause of the cerebral infarction. The presence of a carotid constriction must be explored preoperatively in aged patients scheduled to undergo extensive manipulations in the neck

Freestanding monolayers of two-dimensional particle arrays, in which fine particles are two-dimensionally self-assembled in a highly oriented manner, was prepared to examine the influence of substrate on the transmission spectra of 2D particle array; as a result, the spectrum of the freestanding 2D particle array has less noise than that of the 2D particle array on the substrate, and besides, agree with the theoretical result particularly in the near-field discussion.

We demonstrated the plasma etching of a (001) rutile Nb–TiO2 substrate using SF6 plasma. A vertical etching profile and a smooth etched surface were obtained. In addition, the angled etching of a (001) rutile Nb–TiO2 substrate was achieved in a conventional SF6 reactive ion etching system for the first time. The etching angle was determined by the angle of the groove of the holder. We believe that our simple dry etching technique is suitable for the formation of a three-dimensional photonic crystal with complete photonic bandgap (CPBG) and optical waveguides.

An induced-current-generated system using the nonequilibrium phenomena of water, nitrobenzene, and trimethylstearylammonium chloride is proposed. A nitrobenzene droplet spontaneously carried a smal...

We demonstrated the fabrication of a photonic crystal structure of a (001) rutile TiO2 substrate by deep reactive ion etching (RIE) using SF6 plasma. A vertical etching profile and a smooth etched surface, which satisfy the requirements for optical device application, were obtained. We think that this proposed process is useful for the microfabrication of TiO2-crystal-based optical devices, such as photonic crystals with a complete photonic band gap (CPBG) and optical waveguides.

A six-rayed star-like nanostructure was prepared by a combination of colloidal self-assembly, thermal sintering and chemical etching, which enables the tuning of both size of the particles and neck diameter. In this nanostructure, six nanotips are arrayed in a symmetric and planar arrangement on a spherical particle. Localized surface plasmon resonance characteristics were also clarified.

Highly attractive periodic sub-microstructures were formed in multilayers of two-dimensional fine-particle arrays by means of an oxygen-plasma etching technique. The enhancement of anisotropic etching in multilayers produced these attractive structures, since polystyrene particles (1 μm diameter) in the top layer had worked as protective sidewalls at high power (over 100 W) and low pressure (20 mPa).

Porous spherical CeO 2 particles were prepared by impregnation of a cerium precursor solution into organic monolith sphere particles, with subsequent firing at 500 °C in air. The single-phase CeO 2 powder had specific surface area of greater than 140 m 2 /g. Photodeposition with UV illumination loaded Au onto the CeO 2 particle surface, which changed from yellowish to purple because of localized surface plasmon resonance (LSPR). The Au-loading increased photocatalytic decomposition activity of the CeO 2 powder for gaseous 2-propanol (IPA) under visible light. Thermal desorption of IPA, which was adsorbed to all porous spheres, provided flux to the photocatalytic reaction field of the sphere outer surface.