In order to prepare a cation-exchange membrane, trifluoromethanesulfonic acid (TFMS) and octafluorocyclobutane (OFCB) were plasma-polymerized. Addition of water vapor to the plasma reactor was more effective in preserving the sulfonic acid group in the polymer matrix than was the addition of argon (Ar). Addition of hexafluoropropene (HFP), known as a polymerization promoter, scarcely improved the deposition rate. However, plasma multiphase polymerization, which we called the plasma polymerization process when reactant monomer materials existed in different phases, was effective in accelerating the rate. This technique also increased the ionic conductivity of the resultant plasma polymer. It was found that the polymer film grew uniformly over a 50cm² area. A very high ion-exchange capacity of the polymer was obtained using a method that yielded an approximate value.

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The use of a variable duty cycle pulsed plasma, in lieu of the conventional continuous-wave operational mode, is employed to provide enhanced film chemistry control during polymer film formation. This film chemistry control is illustrated with studies of perfluorocarbon polymers and by synthesis of electrically conductive films from pyrrole. The ability to synthesize polymer films under very low power inputs, using the pulsed technique, permits generation of relatively linear polymeric structures. Contrasts in several important plasma variables under continuous and pulsed modes are identified and discussed in terms of their influence in providing added film chemistry control under pulsed conditions

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The deposition rates of plasma-polymerized (pp-) films of vinyl acetate, vinyl trifluoroacetate, vinyl 2-chloroacetate, vinyl butanoate, vinyl pivalate, vinyl 2-butenoate, vinyl hexanoate and styrene are determined by the quartz crystal microbalance. Using the same polymerization conditions (100W RF and 100 Pa vapor pressure) for the various monomers, the deposition rates were determined to be constant within the interval measured. The deposition rates of pp-vinyl acetate, pp-vinyl trifluoroacetate, pp-vinyl 2-chloroacetate, pp-vinyl butanoate, pp-vinyl pivalate, pp-vinyl 2-butenoate, vinyl hexanoate and pp-styrene were scattered on the different position of measure on the position of the lower electrode in the plasma polymerization equipment. The average deposition rate of pp-vinyl acetate was 0.28μg/min. The average deposition rate of pp-vinyl trifluoroacetate was higher by 15 times, and that of pp- vinyl 2-chloroacetate was higher by 23 times than that of pp-vinyl acetate. The average deposition rate depended on the chemical structure of the monomer.

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Diamondlike carbon (DLC) thin film was prepared by the plasma polymerization of H₂/CH₄ on Al plate for an application to a dielectric electrode in clinical bioelectric measurements. The DLC films obtained had a high dielectric constant of as high as 12 and very low dielectric loss of about 0.03-0.06, which indicated that they worked as capacitors. The DLC films also had excellent mechanical properties, great hardness, adhesivity, and durability, although their thickness is only around 10nm. The barrier property of the DLC films against a physiological salt solution was also satisfactory. In the simulation measurement of electrocardiogram, an oscillated signal passed through the DLC film with a physiological salt solution was detected by a synchroscope with an advance of π/2 as in the theory. A possibility of the use of the DLC film for the application to clinical bioelectric measurements was suggested.

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Pyrene-based nano-spheres were synthesized under RF-plasma conditions in an originally designed plasma reactor. The reactor configuration allows the processing of non- volatile, liquid-phase organic compounds or their solutions in volatile solvents, by atomizing them during their injection into the low-pressure reaction vessel. It has been shown that saturated benzene solution of Pyrene generates under Ar-RF-Plasma environments uniformly sized, hard spherical nano-particles. The structure and the thermal behavior of microsphers were analysed using X-ray photoelectron microscopy (ESCA), FTIR spectroscopy and differential thermal analysis (TG/DTA). Silver layers, composed of nanoparticles were deposited on formaldehyde-RF-plasma functionalized polyethylene (PE) surfaces by taking advantage of the Tollen's reaction. The presence of aldehyde functionalities and the silver on the modified PE surfaces were evidenced using ESCA, Energy dispersive X-ray analysis spectroscopy, SEM, and AFM techniques. High concentration of water-based colloidal (nano-size silver particles) silver solutions were also prepared under Dense Medium Plasma (DMP) plasma environments, and the strong bactericide effect of the silver solutions were evaluated. Applications of nano-particle systems are discussed.

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A film of expanded poly(tetrafluoroethylene) abbreviated here as ePTFE shows no penneabilities in aqueous solutions because of its hydrophobicity. However, the film of ePTFE grafted with acrylic acid (ePTFE-g-PAA) by the combined use of oxygen plasma treatment and photografting gains excellent permeabilities of some hydrophilic solutes maintaining considerably high mechanical strength. In addition, the permeation of insulin through the ePTFE-g-PAA film can be controlled by the pH change in the medium. Using the enzymatic reaction of glucose oxidase with glucose, we have controlled the permeation of insulin through the ePTFE-g-PAAfilm.

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Photodegradation of organosilane self-assembled monolayers (SAMs), under the presence of atmospheric oxygen molecules, has been studied using an excimer lamp radiating vacuum ultra-violet (VUV) light of 172nm in wavelength. The SAMs were prepared on Si substrates covered with native oxide from a precursor molecule of octadecyltrimethoxysilane [CH₃(CH₂)₁₇Si(OCH₃)₃, ODS]. Each of these SAMs was photoirradiated under a controlled pressure from 10 to 10⁵Pa. As confirmed by water contact angle measurements, infrared reflection-absorption spectroscopy and X-ray photoelectron spectroscopy, the SAMs were decomposed and removed due to the VUV-irradiation. This photodegradation mechanism is ascribed to dissociative excitation of C-C and C-H bondings in the ODS molecules and to subsequently proceeded oxidation with atomic oxygen radicals generated simultaneously by the VUV-irradiation of O₂ molecules. This VUV-degradation of organosilane SAM was, furthermore, applied to to photolithography in which the SAM served as photoresist. A micropattern of 2μm in width was successfully transferred on the Si substrate by a simple photomask-contacting method.

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Quenching of imidazoyl radicals (Im•) in photoinitiator systems comprising an aminostyryl dye and a radical generating reagent by acrylate monomers in a poly(methyl methacrylate) (PMMA) film was investigated by a laser flash photolysis using a total reflection cell, as well as quenching of Im• by oxygens in the presence and absence of poly(vinyl alcohol) (PVA)-over layer as an oxygen varrier.

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Two-type-azide compounds for thermal-laser photoresists have been investigated. One was an azide-pendant poly(vinyl ether) as a binder polymer for positive imaging, and the other was a cyanine dye azide for negative imaging.

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Sensitization mechanism of a sensitizer dye with a radical-generating reagent, 2-[p- (diethylamino)-styryl]naphtho[1, 2, d]thiazole (DNT) with 3, 3′, 4, 4′tetrakis(t-butyl-dioxycarbonyl) benzophenone (I) in toluene has been investigated by a picosecond laser flash photlysis.

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The unique properties of the photo-oxidation induced polycondensation resin (POP resin) were experimentally investigated using ¹H NMR analysis, photolithographic evaluation and photo-DSC analysis. While a conventional photo-radial polymerization (PRP) type resin showed the phenomenon of reciprocity law failure at low intensity irradiation and decreasing thickness of the developed film with increased oxygen partial pressure, oxygen was found to improve the sensitivity of the POP resin Post-exposure baking (PEB) also enhanced the curing of the POP resin. The ¹H NMR study indicated that the precursor at the crosslinking point is relatively stable at room temperature. The effectiveness of C₆₀, added to the POP resin was discussed on the basis of the photo-DSC analysis.

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Novel five oxetane monomers were evaluated in photo-cationic curing system. The heat of polymerization of monomers in the formulation with cycloaliphatic diepoxide monomer were measured using photo-DSC. In the formulation, the viscosity were reduced effectively keeping high surface cure rate. Monofunctional oxetanes enhanced the flexibility of cured film. Difunctional oxetanes exhibited improved solvent resistance.

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In several recent reports, the efficient photoinitiated polymerization by excited state maleimides have been shown in numerous acceptor/donor pair combinations [1-10] The strong hydrogen abstractability of the excited triplet state MI has also been evaluated in initiation of acrylate polymerization and the importance of available abstractable hydrogens has been verified [11]. The unique feature of maleimides in general is its dual effect of simultaneously acting as a photoinitiator and as a polymerizable monomer. The mechanistic evaluation of the photoexcitation process was accomplished by laser flash quenching studies. Rates of polymerization and degrees of monomer conversion as a function of irradiance were calculated from photo-DSC and Real Time Infrared Spectroscopy (RTIR) measurements

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It was demonstrated that α-aminoketones work effectively as photobase generators in epoxy-based compositions. After irradiation they accelerate the thermal crosslinking reaction of phenol novolac epoxy resin with polyacrylate having carboxylic acid groups despite of their high latency before irradiated. The acceleration effect depends on the structure of the photogenerated amines. Conformational calculations of the α-aminoketones and the related compounds suggest that folded conformations contribute to the latency of the amine moiety. In the conformations, the bulky benzoyl group of the aminoketone shields the amino nitrogen from acidic species present in the composition. By irradiation, the benzoyl part is cleaved and the active tertiary amine base with small substituents is eventually liberated. The investigation using model amines supported the explanation. The compositions used for this study can be utilized in the base-catalyzed imaging applications.

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We investigated the laser ablation of an elastomer composite with nanosecond- (ns-), picosecond- (ps-) and femtosecond- (fs-) pulsed UV lasers (ns-laser: λ=248nm, τ=30ns; ps-laser: λ=263nm, τ=8ps; fs-laser: λ=248nm, τ=500fs). Upon laser irradiation, a unique microstructure on the surface of the elastomer composite (acrylate polymer) containing carbon black (particle size: 18-30nm) was observed. The laser-ablated surfaces were analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The formation mechanism is discussed in terms of thermal effects induced by the different pulse durations of the lasers.

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