Isamu Karino

Molecular Orientation in Polymer-Dispersed Liquid Crystals Using Time-Resolved FT-IR

Molecular orientation of nematic microdroplets in polymer-dispersed liquid crystal (PDLC) films has been investigated by time-resolved FT-IR (TR/FT-IR) in the presence of an applied electric field. Two kinds (fast and slow) of reorientation processes are found, and these may be attributed to reorientation of liquid crystal molecules at the surface and the central region of droplets. In addition, an induction time has been observed before the onset of the actual reorientation. It is suggested that there are no essential differences between rigid and flexible molecular segments with respect to reorientation dynamics of at least 1 ms time resolution. TR and micro-FT-IR techniques have been combined in order to study the reorientation dynamics of the different regions of droplets.

Separation and characterization of by-product oligomers in epoxy resins by reversed-phase high-performance liquid chromatography

Abstract Three series of monoepoxide by-product oligomers in diglycidyl ethers of bisphenol A type epoxy resins were separated by reversed-phase gradient elution high-performance liquid chromatography. The by-product oligomers studied have a functional group other than a 2,3-epoxypropyloxy group as an endgroup: they have a 2,3-dihydroxypropyloxy, a 2-hydroxy-3-methoxypropyloxy or a 2-hydroxy-3- p-tert. -butylphenoxypropyloxy endgroup. Three oligomers of each series of by-products were isolated and characterized by infrared, mass and carbon-13 nuclear magnetic resonance spectrometry.

First Observations of 0.1 μm Size Particles on Si Wafers Using Atomic Force Microscopy and Optical Scattering

We have developed a new technique on the basis of an optical scattering phenomenon to link the coordinates of a commercially available wafer inspection system (WIS) to an analyzer with a high precision of ±0.1 μm. This new technique has been installed in a large sample atomic force microscope (AFM) capable of observing wafers of 8 in. size. One of the most remarkable features of this newly developed AFM is the ability to observe the same position on a wafer before and after certain processes. In this paper, we report on the results of the first observations of 0.10 μm size particles such as crystal-originated particles (COPs) and dusts on a polished (100) CZ-type Si wafer before and after SC1 cleaning by using the newly developed AFM. It was first found that the 0.10 μm size COPs are inherently juts before SC1 cleaning. After SC1 cleaning, these COPs turned into a deep crystalline pit. These pits run parallel to the axis of the wafer and have four facets with an angle of 54° with respect to the surface of the wafer. Second, the actual size of the dust particles were found to be much bigger than expected by using the WIS. The difference is considered to be attributed to the correction method used in the WIS by comparing with 0.10 μm in size polystyrene latex standard particles. These results show that the AFM combined with an optical scattering system is useful in the evaluation of 0.1 μm sized particles as well as in the wafer cleaning process.

Instrumentation of a wafer inspection large sample atomic force microscope

Particle detection at the 0.1 μm level has become increasingly important in producing reliable devices that demand smaller line widths. However, because the position alignment accuracy between the commercial optical particle inspection system and the particle evaluation instrument is insufficient, it is extremely difficult to detect 0.1 μm size particles. To solve these problems, we have succeeded in increasing the coordinate positioning accuracy at the 0.1 μm level by combining a large sample atomic force microscope (G. Bing, C. F. Quate and Ch. Gerber, Phys. Rev. Lett., 56 (1986) 930) with an optical scattering system. Using this system, we can now observe defects and particles on bare wafers and the possibility of particle detection is virtually 100%. Furthermore, the observation time necessary to position on a particle is substantially reduced.

Polar-Polar Interaction and Boundary Phase Structure Between Reinforcement and Matrix in a Polymer Composite

Abstract This paper describes an attempt to correlate the nature of polar-polar interaction between the reinforcement and matrix in a polymer composite with the boundary phase structure formed in contact with the reinforcement. It is shown by analyzing the mechanical dispersion data that the reinforcement-matrix interaction of Kevlar fiber reinforced poly(hydroxypropyl ether of bisphenol A) (P) is increased by blending poly(ethylene oxide) (E) or poly(ethylene adipate) (A) as a part of matrix, and that E is more efficient than A for the increase of the interaction. These results can be supported at the molecular level from the inspection of the Fourier transform infrared spectra on the Kevlar fiber coated with matrix polymers and the mixture of matrix polymers with benzanilide, which is used as a model compound of Kevlar fiber. It can be shown from the electron spectroscopy for chemical analysis on the films of PIE and P/A blend polymers formed on nylon 6 substrate (N), which is also used as a model mater...

Interactions between polyimide-coated carbon fiber and epoxy resin.

炭素繊維強化高分子複合体における強化材-マトリックス間相互作用を高める目的で, ポリイミド樹脂薄膜を被ふくした炭素繊維で強化されたエポキシ樹脂複合体について力学的及び分光学的特性を調べた. ポリイミド薄膜は芳香族ジアミンとテトラカルギン酸二無水物を炭素繊維上で直接重合することにより形成した. E”およびtanδ-温度曲線上で, 主分散の高温側に一つの副分散が現れる. 積層試片の剥離強度と複合体の弾性率及び強度に対する繊維の有効係数はポリイミド処理が行われていない繊維で強化された場合より大きくなる. これらの結果はエポキシ樹脂とポリイミド被ふく炭素繊維の間の相互作用が増加したことを示している. フーリエ変換赤外スペクトルからエポキシ樹脂とポリイミド間にある種の相互作用が生じていることが認められる.