One of the most serious problems in fluorescence bio-imaging is the limitation of observation time due to color-fading of the fluorescence probes and damages on the bio system, both of which are caused by the excitation ultraviolet irradiation. This problem can be solved by using an upconversion emission of rare-earth doped inorganic nanophosphors under infrared excitation. For the application of nanophosphors as bio-imaging probes, surface modification by biocompatible polymers is needed to obtain biological functionality in organic tissues. In this paper, authors demonstrate the formation of poly(acrylic acid) (PAAc) and &alfa;-acetal-poly (ethylene glycol)-block-[poly (2-(N,N-dimethylamino) ethyl methacrylate)] multilayers on the Er-doped Y₂O₃ nanoparticles as an upconversion nanophosphor. The existence of the layers was confirmed by using zeta electrometry and infrared vibrational spectroscopy measurements.

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Surface relief gratings (SRG) with anisotropic gratings in photo-cross-linkable liquid crystalline (LC) polymethacrylate films comprising 4-(4-methoxycinnamoyloxy)-biphenyl (MCB) side groups were fabricated by irradiating with a linearly polarized ultraviolet (LPUV) light through a grating photomask and subsequent annealing at LC temperature range of the film. A reorientation of the mesogenic groups accompanied the molecular diffusion after the annealing, although the molecular diffusion and the reorientation direction depended on degree of the photoreaction of the mesogenic groups and the polarization (E) of LPUV light. When the degree of the photoreaction was around 7 mol%, molecules moved from illuminated area to non-illuminated area, and the molecular reorientation direction was parallel to the grating line regardless of E of LPUV light. In contrast, the diffusion direction was determined from the non-illuminated area to the illuminated region, and the molecular reorientation direction was always parallel to E of LPUV light when the degree of the photoreaction was around 20 mol%. All the fabricated SRGs showed characteristics of the polarization dependent gratings due to the surface relief formation and the molecular reorientation direction. The diffraction properties of the SRGs were good agreement with theoretical analyses.

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A polymer-stabilized technique with a bias voltage (BPS) combined with a photo-alignment method has been applied for a vertical LC alignment to achieving stable and uniform pretilt angle as low as 80deg. An initially-pretilted vertically-aligned LC medium produced by a photo-alignment method, which is doped with a small amount of UV-curable monomer, is followed by a BPS method for further increase of the pretilt angle. The achieved pretilt angle as low as 80deg. by the combined method is very stable and uniform. This result clearly demonstrates the usefulness of the present BSP method to achieve very low pretilt angle for vertical LC alignment.

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The polymer-stabilized ferroelectric liquid crystal (PS-FLC) photocured under the application of an AC electric field shows a monostable V-shaped electrooptical characteristics. However, it is not clear how the V-shaped electrooptical characteristics can be realized in the PS-FLC. In this study, we have investigated in detail the elecrooptical characteristics of PS-FLC and the effect of the polymer stabilization on the molecular alignment structure. The electrooptical characteristics and microscopic textures of PS-FLCs, which were photocured under lots of conditions such as the concentration of doped monomer, the frequency of AC electric field and temperature, were measured. Since the existence of domain structure is confirmed in the PS-FLCs, it is guessed that two types of domain, in which there are two alignment directions monostabilized by the mesogenic side chains of polymer photocured under the application of a bipolar square-pulsed AC electric field, would coexist.

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We have developed and commercialized Low-retardation TAC Film for protection films of LCD's polarizer, named FUJI FILM 'Z-TAC^®'. We used advanced technologies to control TAC film's in-plane birefringence and out-of-plane birefringence. By using these technologies, Re value (in-plane retardation) and Rth value (out-of-plane retardation) of this TAC film are both nearly zero. With this novel optical property of both nearly zero Re and Rth for the first time in the world, this Low-retardation TAC film can reduce the color-shift of LCDs at oblique incidence, for especially IPS mode LCDs. Also, this Low-retardation TAC film can use existing cost-effective roll-to-roll manufacturing process for polarizer.

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Solution-processed organic electrophosphorescent devices with arylamine polymer buffer layer have been investigated. Device characteristics were similar to the device using commonly used conducting polymer as buffer layer, and the uniform emission was obtained in the device. The lifetime of the device, defined as half-luminous at an initial luminance of 1,000 cd/m2, was 40 h.

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The phosphorescence intensities of the green phosphor, fac tris(2-phenylpyridine) iridium [Ir(ppy)₃], in a polymethylmethacrylate [PMMA] host matrix are independent of temperature, while the phosphorescence lifetimes increase significantly at temperatures below T ∼ 50 K. In this paper, to rationalize the characteristic temperature dependence of the transient phosphorescence of Ir(ppy₃3, we propose a model where the triplet excited states split by spin-orbital interaction, forming three levels in which mutual energy transfer between the sub-levels of triplet states occurs. We discuss the validity of this numerical model by comparing with the experimental result of the transient phosphorescence in a PMMA host matrix and demonstrate that the model well explains the characteristic temperature dependence.

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We report on a method of fabricating multi-layer polymer light emitting diodes in this study. A hole transporting layer (HTL) was cross-linked by UV irradiation. It was found that both free radical and cationic polymerization mechanisms could be applied to cross-link the HTL and that the hole transporting properties of HTL were not greatly reduced by the UV cross-linking reactions. An emitting layer could also be cross-linked by UV-irradiation without damaging its light emitting properties. By cross-linking the hole transporting layer and emitting layer, bi-layer and multilayered polymer light emitting diodes with an HTL and an electron transporting layer (ETL) can be fabricated through a wet process method, such as spin coating. The characteristics of light emitting diodes, such as efficiency and life time, can be greatly improved by introducing a hole transporting layer into the polymer light emitting diodes. The improvements in the properties of PLED due to a multilayer structure were attributed to improvements in the carrier injection balance of the emitting layer.

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It is needed for flexible transparent substrate to have not only the flexibility but also the ability of the material barrier as same as glass material. We paid attention to the nanocomposite barrier technology as a technique for making both its flexibility and the barrier property that are opposed to each other. This is a technology for appearing the barrier property by bringing the effect of the diffusion delay, so-called "Maze", to the diffusion of the material (gas molecule etc.) that passes by dispersing and combining a small plate of material impermeability filler on the nanometer scale into the resin.
In this study, the possibility of being compatible with flexibility and barrier property is shown by improving the effective aspect ratio using the small plate filler in the nanocomposite barrier technology.

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Organic light emitting diodes (OLEDs) with thin-film passivation and plastic substrates are expected to provide a means of producing next-generation flat-panel displays that are thin, lightweight, and flexible. Thick silicon nitride (SiNx) films fabricated by a plasma-CVD method are already recognized as being a practical passivation film for OLEDs, but these are not suitable for flexible applications for automobiles as cracks are generated in the films as a result of the bending or thermal stress. To overcome this problem, we have developed plasma-CVD SiNx/ plasma-polymerized hydrogenated carbon nitride (CNx:H) multi-layer films and epoxy substrates that increase the longevity of passivated OLEDs in flexible applications for automobiles. The films exhibit a high barrier performance against moisture even in high stress conditions, because the stress in the films is released by the soft CNx:H layers and no cracks are produced. The epoxy substrates also show good stability at high temperatures because of their high glass transition temperature. Indeed, the OLED thus formed lasted over 1000 hours in driving tests at 85oC, that is the temperature which can arise in automobiles.

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Bathocuproine (BCP) is often used as a hole-blocking layer in organic light-emitting diodes (OLEDs) and as anti-migration layer of exciton in organic solar cells. However, BCP is easily polycrystallized after vacuum deposition immediately. We can suppress the polycrystallization of BCP thin film by means of organic alloy with the other material.

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For the purpose of the introduction of nitrogen-containing functional groups on Ag particle, we treated it with low-temperature plasma by three steps. In the first step, Ag particle was treated with H2O plasma. After the treatment, some oxygen-containing functional groups such as hydroxy and carboxy groups were found on the Ag particle surface, which became hydrophilic. As the second step, triethoxyvinylsilane was adsorbed on the surface of the H2O-plasma-treated Ag particle, which became hydrophobic. In the final step, the Ag particle was treated with NH3 plasma, resulted in hydrophilic surface. The surfaces of the Ag particles were analyzed mainly with XPS, and their dispersibility was examined. From the XPS analysis, some nitrogen-containing functional groups were found to be introduced on Ag particle. This Ag particle is expected to be applied for conductive adhesives and many other fields as a functional powder.

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Experiments to observe anthracene radiation excited by hot electrons emitted from PZT ferroelectric substances by polarization inversion were performed with using 2.5 and 1.0 mm thick PZT disk type samples. The PZT electron source was fabricated with sandwiching a comb and a flat type electrode formed on the both sides of PZT plate. Then about 1nm thick semi-conductive C-S-Au film was equipped on the comb type electrode side of PZT element. The anthracene layer was over coated on the C-S-Au film on the comb type electrode. When the polarization was inversed by an impulse voltage application, some radiation was observed on the comb type electrode side. It was difficult to distinguish the anthracene radiation from the surface discharge. In order to distinguish the anthracene radiation, additional experiments must be performing by optimizing the semi-conductive properties of C-S-Au film depending on the atomic composition and the thickness, the comb type electrode structure and the impulse voltage shape for the polarization inversion.

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Expanded PTFE films with pH-responsive acrylic acid grafted chains were prepared by the combined use of the oxygen plasma treatment and the photo-polymerization. GOD immobilized onto ePTFE-g-PAAc films responded to glucose, and so permeation of insulin through the films was clearly observed. To enhance the reaction of GOD with glucose, a Catalase-immobilized ePTFE-g-PAAc film was jointly employed with a GOD-immobilized ePTFE-g-PAAc film.

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Dispersed PE powder was carried into an RF-APG -plasma zone by gas flow, and was treated; treatment time was about 30 ms. Plasma-treated PE powder was gathered by a filter, then measured by chemical derivatization techniques using XPS. Oxidized PE powder showed enough hydrophilicity to disperse in water completely even though the treatment time was quite short. The degree of oxidization could be controlled by changing discharge power and oxygen gas content. Though PE powder was not nitrided enough by NH3/He plasma under any plasma conditions, it was found that nitriding was promoted by increasing the number of treatments.

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We developed localized deposition techniques using an atmospheric-pressure microplasma for on-demand material processing in which only the desired amount of material was prepared at low energy and assembled at a specified location in a one-step process under atmospheric pressure in ambient air. In this paper, we introduce two techniques developed by wire spraying and a technique using liquids as raw materials. These techniques enable us to deposit a wide variety of materials on a specified local area without using toxic gases and can be expected to be useful for on-demand processing

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Plasma polymerized silicone resin thin films were produced at different ambience by introducing different gases. Hydrophilicity and hydrophobicity of the plasma polymerized films were measured by the contact angle made by the water drops to the films surface. Films antifogging property also evaluated during our work. By introducing O₂ gas and HCOOH vapor, we found that the plasma polymer films were showing high hydrophilic and antifogging nature. The films produced in the ambience of CF₄ gas and the carbon fluoride gases found to be high hydrophobic in nature but were not showed any antifogging property.

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A scanning microjet treatment (SMJ) using nitrogen radicals was developed and applied it for controlling biological cells' attachment on biocompatible polymer material, poly(dimethylsiloxane) (PDMS). Previously, we developed an atmospheric-pressure argon/oxygen (Ar/O₂) radical microjet system and used it for modifying PDMS surface. In this study, we examined argon/nitrogen (Ar/Nsub>2) plasma system and compared it with the previous study using Ar/O₂ system in terms of degree of hydrophilicity, chemical state, surface morphology and cell adhesion. The results from the Ar/N₂ system showed interesting phenomena that indicate promising potentials for application in controlling cell adhesion.

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We developed a novel fabrication method of on-demand polymer film synthesis onto a substrate under atmospheric pressure using microplasma polymerization with a laboratory-made torch-type microplasma polymerization apparatus. We used styrene as model monomer for selection of polymerization condition of microplasma-polymerization and evaluation of microplasma-polymerized (MPP-) styrene films. These films were characterized using data FT-IR, EDX, contact angle, and gas sorption property using QCM technique. Characterization results of FT-IR, contact angle, and EDX suggest that MPP-styrene films were oxidized. Results showed that gas sorption properties of MPP-styrene films were controllable by polymerization parameters of VHF power or concentration of monomer gas.

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Pulsed RF plasma graft-polymerized styrene revealed sub nm pattern

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The new type phenylethynyl terminated thermosetting a-BPDA based polyimide has been developed. The alcoholic solution comprising asymmetric BPDA (a-BPDA) derivative, p-phenylenediamine, 1,3-bis(4-aminophenoxy)-benzene and 4-phenylethynylphthalic anhydride derivative was used for the formation of prepreg containing solvent. The prepreg showed excellent processablity for the fabrication of composite using a conventional autoclave and its cured material exhibited high Tg of 365°C and balanced mechanical properties.

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Novel sulfonated diamine isomers, 2,2'-bis(4-sulfophenoxy)benzidine (2,2'-BSPOB) and 3,3'-bis(4-sulfophenoxy)benzidine (3,3'-BSPOB), were prepared by direct sulfonation with fuming sulfuric acid from corresponding diamines of 2,2'(or 3,3')-bisphenoxybenzidine. Sulfonated polyimides (SPIs) were synthesized from these sulfonated diamines of BSPOB and 1,4,5,8-naphthlene tetracarboxylic dianhydride (NTDA) via polycondensation. Tough and ductile membranes were obtained by solution casting method. The SPI membranes with reasonable ion exchange capacities (IECs) displayed high proton conductivity and excellent water stability.

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A positive-working photosensitive polyimide based on semi-alicyclic poly(amide acid) (PAA), 1,1,1-tris(4-[2-(vinyloxy)ethoxy]phenyl)ethane (TVPE) as a crosslinking dissolution inhibitor and a photoacid generator has been developed. PAA was prepared from pyromellitic dianhydride and alicyclic diamine in N,N-dimethylacetamide (DMAc), which has excellent transparency above 365 nm and good solubility for 1 % sodium carbonate aqueous solution (aq.). The resist from the polymerization solution was formulated with photosensitive additives without isolation of PAA. A 23 μm thick film of the PSPI precursor system containing 25 wt% TVPE, 5 wt% PAG exhibited a sensitivity of 160 mJ/cm² and contrast of 1.3 when it was exposed to broadband UV light followed by development in a 1 % sodium carbonate aq. at room temperature. A positive image featuring 40 μm line and space patterns was observed by the contact mode.

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Recently we developed novel poly(ester imide)s (PEsI) possessing a low CTE, a high modulus, a high Tg, high toughness, and a low water absorption at the same time. The present work describes that these PEsI precursors (PEsAA) dispersing diazonaphthoquinone (DNQ) as a photosensitizer gave a good positive-tone fine pattern by development using a 1.0 or 2.38 wt % TMAH aqueous solution. A PEsAA film containing 30 wt % DNQ showed no sufficient difference of the dissolution rates between the exposed/unexposed areas. Then, an imide-containing fluorinated diamine monomer was synthesized and introduced into the PEsAA main chains by copolymerization to control the solubility of the PEsAA in TMAH. The use of PEsAAs possessing an imide content of 15?20 % enabled us to form fine patterns. The thermally cured PEsI film maintained a low CTE, a high modulus, and low water absorption. The introduction of imide-containing fluorinated diamine increased the transmittance at 365 nm and decreased the dielectric constant and water absorption. On the other hand, the use of fluorinated rigid diamine, TFMB made possible to obtain fine pattern without imide-containing diamine in addition to excellent combined properties of the PEsI film.

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The thermal and optical properties of four kinds of aromatic polyimides (PIs) having a common skeletal structure have been investigated using thermogravimetric analysis and UV/Vis absorption and fluorescence spectroscopy. Pyromellitic dianhydride (PMDA) and 1,4-difluoropyromellitic dianhydride (P2FDA) were used as the dianhydrides for model compounds and PIs to examine the charge transfer (CT) nature of the nPIs. In addition, methosy (-OCH₃) group was chosen as the side group to introduce atrong electron donating property to the diamines. The PIs derived from P2FDA exhibit an intense and characteristic absorption band at -550 nm and two independent pairs of the excitation and emission peaks. The spectral data from the modelcompounds demonstrate that the characteristic absorption/emission at 550nm is attributable to the local π-π^* transition with P2FDA moiety. In contrast, the emissions appearing at the longer wavelengths for the P2FDA-based PIs (720-730 nm) and those for the PMDA-based PIs (540 and 620 nm) are closely reatedd to the charge transfer (CT) interactions between the dianhydride and diamine moieties, and their behaviors accord with the calculated molecular orbital energies using the density functional theory.

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