Our final aim is the establishment of the preparation method of syndiotactic polystyrene (sPS) films where photo-functional molecules are three-dimensionally arrayed with a regular orientation. We prepared sPS films including 7-amino-4-methylcoumarin (AMC), a typical dye molecule, by some different procedures and examined the crystalline structure and the orientation of AMC by WAXD together with measurements of polarized fluorescence by rotation of a sample (PFR). The exposure of sublimated AMC gas to stretched sPS films only produced trans mesomorphic phase of sPS without forming sPS/AMC cocrystals. Finally, the preparation method by soaking stretched sPS films in CS2 solution of AMC was found to be a good way to produce sPS films having regularly oriented sPS/AMC cocrystals, though the fraction of cocrystals was still not high.

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Blue phase is an attractive liquid crystal because of the 3-dimensional nano-structure. We have tried to obtain the blue phase using photocurable mesogenic monomers and solidify the blue phase structure by irradiation of ultra-violet light. Furthermore, we have examined the mechanical strength of the solidified blue phase. As a result, we found that the appearance of blue phase strongly depends on the kind and concentration of mesogenic monomers and chiral dopants, and then the blue phase structure can remain even after the polymerization in the case utilizing a strong intensity of ultra-violet light. In the mechanical strength, the solidified blue phase samples are more fragile than the solidified samples which have been photocured in the isotropic or the choresteric phase. This fact may result from a discontinuous lattice structure including defects, i.e. platelet texture, as seen in microscopic texture observation.

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The fluorinated block copolymer containing 2-methyl-2-adamantyl methacrylate (adMM) and perfluoroalkyl methacrylate (Zonyl&Reg;) was synthesized via atom transfer radical polymerization (ATRP) using a copper catalyst. High reactivity of adMM was observed. AdMM was polymerized even at room temperature and the polymer which with narrow polydispersity was observed. Fluorinated homopolymer (PZonyl&Reg;) and random copolymer (PadMM-γ-PZonyl&Reg;) were also synthesized. The polymers were added to the resist model polymer and the relationship between polymer structure and film characteristics were investigated such as hydrophobicity and development behavior. The fluorinated polymers (0-1 wt%), photoacid generator (PAG) (0.2 wt%) and the resist model polymer (9-10 wt%) were dissolved in α,α,α-trifluorotoluene (TFT) and the blend polymer films prepared on Si wafer. The film containing PadMM-b-PZonyl&Reg; showed good hydrophobicity and resist performance compared with films containing the other polymer because self-segregation was promoted with the block copolymer and the low surface energy of perfluoroalkyl group. It is expected that adMM units in fluorinated additives increase resist performance.

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Laser scan lithography was applied to patterning onto surfaces of fine pipes and wires with sub-100-μm diameters. Such patterning is useful for developing micro-coil springs. A prototype exposure system has already been developed, and it has been demonstrated that tiny micro-coils are successfully fabricated. However, patterning reproducibility and coil-width accuracy must be ensured to move to the next step for applying the micro-coils to practical products. Considering these backgrounds, helical patterning characteristics are investigated in detail. At first, 10-μm helical space patterns were delineated onto copper pipe specimens with a diameter of 100 μm to ensure the practical minimum pattern width. As a result, the minute patterns were stably formed with deviations of within &plumn;0.7 μm. Next, helical patterns with a width around 50 μm were delineated onto 80-μm diameter stainless-steel wires to reply the immediate requirements. It was certificated that both patterning reproducibility among the specimens and the pattern width homogeneity in every specimen were very good and sufficient for the practical use.

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Degradation temperature, D.T. of the para-substituted benzene diazo compound (SBD) mixed with various length of multi-walled carbon nanotubes (CNT) : 3-20, 20-40, 40-70 nm, was determined by TDA and DTA in solid. Temperature rise ratio of D.T. of SBD with electron-withdrawing substitutent (WSB) was larger than that of SBD with electron-donating substituent (DSB). It is considered that a cationic diazo group of SBD is easily coordinated by electron-rich CNT surface. The D.T. of SBD with long CNT was higher than that with short CNT. Stabilization energies of diazo compounds with CNT were calculated by WinMOPAC, to be about 37 kJ/mol per diazo molecule. Oxidation treatment of CNT led to better dispersion of CNT particles. Photodecomposition rate of Diazo/PVA resist film with CNT was increased, but effect of CNT length on the photodecomposition was not observed. Shorter ox-CNT in length showed higher transmittance. Hardness of the film with long CNT was larger than that with short CNT. It is considered that degree of packing of the polymer chain with long CNT is higher than that with short CNT.

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We investigated the removal characteristics of an ultraviolet (UV) curable polymer for UV nano-imprint lithography (NIL) using atomic hydrogen, which was generated by the catalytic decomposition of H2 molecules in H₂/N₂ mixed gas (H₂:N₂=10:90vol.%) using a tungsten hot-wire catalyzer. The cured polymers were removed by atomic hydrogen without a residual layer. The removal rate of the polymer increased with rising catalyzer temperature. It was assumed that both enhanced reactivity between atomic hydrogen and polymer by the substrate temperature increase due to radiation heat of the catalyzer and increased atomic hydrogen concentration occurred as a result of the rise in catalyzer temperature. When the distance between the catalyzer and the substrate was 100mm, the catalyzer temperature was 2400°C, and the initial substrate temperature was room temperature, the removal rate of polymers was 0.17μm/min independent of exposure dose to the polymer. The removal rate of polymers was comparable to the removal rate of general i-line positive-tone novolak resist. The polymer adhering to the micro-asperity portion of the mold was removed without leaving a residual layer by grazing-incidence atomic hydrogen.

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We investigated the removal of positive-tone novolak resist, ArF resist, and positive-tone novolak resists into which B, P, and As ions were implanted with a dose of 5X10¹⁴atoms/cm² at an acceleration energy of 70keV (forming ion-implanted resists) using Xe₂ excimer UV light. There was an optimum UV irradiation distance with respect to the removal rate since oxygen could not penetrate into the UV irradiation space when the UV irradiation distance was 0mm, and the intensity of the UV light decayed when the UV irradiation distance was too great. It was confirmed that the resist was not removed in a nitrogen environment because ozone and oxygen radicals were not generated. There is an optimum substrate temperature for the removal rate the same as for the UV irradiation distance. It was considered that the reactivity between resist and the ozone and oxygen radical was enhanced but ozone concentration decreased by decomposition of the ozone to oxygen molecules with a rise in substrate temperature. Under the optimum UV irradiation conditions, the UV irradiation time for complete removal of ArF resist (0.15μm thick) was 4min. Although the ion-implanted resists were difficult to remove by conventional methods, B- and P-ion-implanted resists were removed by Xe₂light.

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The film patterned by the resin Black Matrix (BM) photoresist, which has two features, the lower reflectivity and low stress on environment of a processing developer than the chromium oxide (CrO) photoresist, is applied to the color filter (CF) in the Liquid Crystal Display (LCD). However, the new panel technology, that is required more lower environmental impact, needs lower reflectivity and narrower negative-tone pattern for the resin BM resist in recent years. We investigated the lower reflectivity resin BM resist film with the mill base comprised of the pigment alloyed silver and tin. The thermo gravimetric analysis (TGA) indicated a significant difference on a surface roughness (Ra) measured on an atomic forced microscope (AFM). Moreover, we observed a contact angle of 2-methoxy-1-methyl acetate (PGMEA) on the film with fluorin-cotaning polymer after post-bake at 220°C. From these results, we concluded that the resin BM resist film comprised of the Ag-Sn mill base make lower reflective and narrower negative-tone pattern.

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Polymer structure effects on the dissolution kinetics and deprotection reaction were investigated to understand inherent extreme ultraviolet (EUV) resist characteristics. The effect of protecting groups and protecting ratio on activation energy were observed. Also, the protecting ratio effect on dissolution kinetics was observed. The speed of TMAH penetration into each resist film was different for each resist as the concept of the ″penetration zone″. This indicated that the dominant rate-determining step in resists is TMAH penetration into the resist film. Thus, the dissolution rates were affected by changing the protection ratio of polymer. Moreover, the preliminary evaluation of resist profile for EUV chemically amplified resists was performed by using PROLITH and parameters obtained with EUV exposure tool. Furthermore, the resist patterns were produced by electron beam and the SEM observation results were compared with the PROLITH simulation results. It is important for EUV lithography to select appropriate protecting group and protecting ratio.

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Most manufacturers do not provide details about the photoinitiators contained in dental adhesives. Therefore, it is difficult to choose an optimal combination of dental adhesive and light-curing unit. The purpose of this study was therefore to investigate the spectral emission characteristics of several commercially available light-curing units and the spectral transmittance characteristics of contemporary dental adhesives. Spectral distributions of emitted lights were determined on a UV-vis-NIR spectrometer for three quartz-tungsten-halogen (QTH) light-curing units (Jetlite 3000, J. Morita; New Light VL-2, GC; D-Lux 2000, Dentrade) and three light-emitting diode (LED) light-curing units (Curenos, Shofu; G-Light Prima, GC; Bluephase, Ivoclar Vivadent). Spectral distributions of light transmittance in contemporary dental adhesives (Scotchbond Multi-Purpose, 3M ESPE; Adper Single Bond, 3M ESPE; One-Step, Bisco; AQ Bond Plus, Sun Medical; OptiBond All-in-One, Kerr; Clearfil S³ Bond, Kuraray Medical; G-Bond, GC; Tokuyama Bond Force, Tokuyama Dental; GBA 300 experimental, GC) were also determined. Each of the three QTH light-curing units had a wide emission range of 380-510 nm. A narrower emission range was observed in the LED light-curing units than in the QTH light-curing units. It was found that 2 LED light-curing units had dual peak wavelengths in both the blue and violet regions of the visible spectrum. There were some variations in light transmittance, and therefore the results suggested that some dental adhesives contain alternative photoinitiators besides camphorquinone. The selection of suitable light-curing units on the basis of the light absorption of dental adhesives and resin composites in dental clinics is of upmost importance.

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Atmospheric plasma discharges at a gas-liquid interface have recently paid great attention because of many possible applications. Although chemically reactive species, e.g., OH, O, O₃, H₂O₂, play an important role in many applications, their transport mechanism has not yet been clarified. In this study, flow fields in air and water were observed to elucidate the mechanism of chemical species transport. We used a dielectric barrier discharge ignited between a metal pin electrode and the surface of water by applying high AC voltage of negative polarity to the metal pin electrode. To visualize the chemical species distribution in the water, methyl red solution was used and color change was observed. In addition, the relationship between the flow field and the color change of methyl red solution was examined. Furthermore, a computational study was conducted to understand the effect of the flow on the chemical species transport. The results show that the chemical species in the water were transported mainly by the circulating flow induced by the discharge.

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Rare-earth doped yttrium oxide (Y₂₃3) is a good candidate to be used for the near infrared (NIR) fluorescence bioimaging. Coating of Y₂O₃ nanoparticles with polymer is one of the key issues to use Y₂O₃ nanoparticles as a fluorescent probe for the NIR fluorescence bioimaging. We developed a plasma fluidized bed for homogeneously exposing nanoparticles to the atmospheric plasma, which is expected to enhance chemical reactions in a system involving organic materials. Poly(acrylic acid) (PAAc) modified Y₂O₃ was exposed to the atmospheric plasma by using the bed. Improved acid durability and dispersion stability was observed after plasma treatment. These improvements do not correspond to thermal reaction of intra-reaction in PAAc chain, but can be assigned to a chelation reaction between Y3+ on the Y₂O₃ particles surface and COO^- groups in PAAc chain.

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Liquid marbles, non-stick droplets encapsulated by fine particles, were prepared with cellulose powders (CPs). Since CPs were very hydrophilic, they were treated with O2 plasma, followed by the adsorption of tetramethylcyclotetrasiloxane (TMCTS) before liquid-marble formation. Plasma treatment of CPs was carried out in a flask-rotation type reactor, which required 45 min to adsorb adequate amounts of TMCTS. In TMCTS adsorption, a successive reaction with ammonia was utilized for a secure chemisorption of TMCTS. After the adsorption, CPs became very hydrophobic. The prepared liquid marbles, water drops surrounded by TMCTS-adsorbed CP, were so robust that their compressibility exceeded 90%. A liquid marble containing 0.1-M CoCl₂ aq solution was applied for an ammonia gas sensor. In the presence of a highly diluted ammonia solution (0.6%) in a desiccator, the color of the liquid marble turned from pink to blue within a few minutes.

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Polytetrafluoroethylene (PTFE) sheet surface was treated by the diborane/H2/He plasma for the deflurination to improve the adhesive strength. Diborane was generated by the H₂/He plasma treatment of a boron plate and was transported to the plasma zone for PTFE sheet treatment. And then, the defluorination plasma treatment with this diborane/H2/He mixture gas performed PTFE sheet. Fluorine atom content of treated PTFE surface was decreased to about twentieth of that of untreated PTFE. The adhesive strength between treated PTFE and epoxy glue became stronger enough for practical use

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Two-step surface modification of metal or glass substrates has been developed for the long-term reliability and safety of biomedical devices (stents, catheters, blood contacting parts,etc) and cell microarrays for cell diagnosis and cell recovery. First step, carboxylic group (COOH)_s containing DLC (DLC/COOH) were coated on an aluminum surface by a plasma enhanced chemical vapor deposition (PECVD). Second step, an anti-thrombogenic, poly(N-α-(methacrylamide-L-lysine) (PLysMA) or poly[2-(meth- acryloyloxy)ethyl phosphorylcholine] (PMPC) was grafted on the DLC/COOH surface by plasma irradiation-post polymerization technique.
Furthermore, to develop novel cell microarrays having regulatory-arranged glass spots and coated the surface with DLC/COOH around the spots for evaluation of cell function and selection of targeting cells by immobilization of single cells on the spots, the microarrays were also grafted with PMPC on the DLC/COOH by the plasma irradiation-post polymerization technique. Surface biocompatibility and characterization were examined by SPM, XPS, and adsorption of plasma proteins.

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Poly(tetrafluoroethylene) (PTFE) films grafted with P(NIPAAm-co-HIPAAm) have been prepared by the combined use of the Ar plasma treatment and photografting. By the Ar plasma treatment the hydrophilicity of PTFE film surface was achieved by irradiation of the short time. The surface compositions of the grafted PTFE films were analyzed by ESCA and the thermo-responsive properties were investigated by contact angle measurements toward water. The composition of HIPAAm in the monomer mixture was controlled to aim for increasing the phase transition temperature of PNIPAAm, 32°C. The phase transition temperature of ePTFE-g-P(NIPAAm-co-HIPAAm) film increased with the ratio of HIPAAm in the monomer solution. The transition temperatures of ePTFE-g-P(NIPAAm-co-HIPAAm) (N:H=70:30, 50:50 and 20:80) films were about 40°C , 52 and 83°C, respectively. It is thought that the Ttr of the ePTFE-g-P(NIPAAm-co- HIPAAm) film can be set more minute by regulating the composition of HIPAAm. Therefore, many applications in wide fields will be developed in future.

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