New highly porous p-aramid aerogel was produced from p-aramid/DMSO/TBAF solution. The solution was gelled to obtain shaped three-dimensional objects, and that p-aramid DMSO-gel was regenerated by solvent substitution followed by supercritical drying with CO₂. To investigate the influences of hydrogen bonds on aerogel preparation, two kinds of p-aramid fiber, Kevlar^® and Technora were employed. The effects of different procedure parameters, such as concentration of hydrogen accepter, TBAF, homogenization time and type of exchange solvent on the formation of p-aramid gels and aerogels after supercritical CO₂ (scCO₂) drying were discussed by measuring the homogenization time, compression modulus, volume shrinkage, and surface morphology of the gels and aerogels. Consequently, the Kevlar^® aerogel with density of 0.018 g/cm³ was obtained under optimal conditions.

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The purpose of this study is to confirm a rotation phenomenon around the fiber axis of a kenaf fiber, a representative multi-cell type fiber, during tensile loading, and clarify the rotation mechanism through 3D finite element analysis. The degree of rotation was quantified by measuring rotation angle during the tensile test of a single fiber, by giving a free mechanical condition perpendicular to the tensile direction. Results showed that, although many fiber specimens did not rotate during tensile loading, the rotation was confirmed for approximately one fourth of all the specimens. Young's moduli of the rotation identified specimens are almost the same level as non-rotating fibers, while these fibers indicated a slight decrease in strength, as compared with non-rotating fibers. The coordinates transformation matrix simulating a spatial spiral structure of cellulose microfibrils (CMF) was constructed, and applied for 3D finite element analysis. The calculation results show that rotation occurs in one-cell and seven-cell finite element models, but the magnitude of rotation is much smaller in the seven-cell model. Furthermore, a cell twisted finite element model was carried out to simulate a small-scale disorder in the multi-cell orientation structure, which was observed on the kenaf fiber surface. Finally, it is estimated from the calculation results that rotation occurs only for the fiber in which the mechanical balance between CMF spiral structure and multi-cells' intertwist is not enough.

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Coloration behaviors of the wool fabric dyed with p-aminophenol(pAP)/p-phenylenediamine(pPDA)/ p-amino-o-cresol(pAOC) mixed oxidation dyeing system were investigated by varying the dyeing conditions, such as the composition ratio of their dye intermediate, the concentration of hydrogen peroxide and the bath ratio of dyeing system. In the case of pAP/pPDA/pAOC (1:1:2) dyeing system of pH10 with the addition of 90ml/L hydrogen peroxide, the chromaticity in the a*b* diagram varied to draw a hairpin curve, which showed that the color of dyed sample turned a dark reddish orange having lower saturation through a dull orange having the highest saturation from a dull yellowish-orange, with the increase in dyeing time. As a result of dyeing under various conditions, it has been found that (1) the varied composition ratio of dye intermediates affects significantly the difference in the hue angle and the chroma between the fabrics dyed for 5 min and 120 min, and that (2) the coloration of the fabrics in the 1:1:2 dyeing system of pH10 with the addition of 5ml/L hydrogen peroxide is dependent on the uptake of the pPDA/pAOC coupling dyes which generate preferentially even at low concentrations of hydrogen peroxide, and that (3) the uptake of pPDA/pAOC coupling dye increases more than that of pAP/pAOC coupling dye with decreasing in the bath ratio of the dyeing system.

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A highly selective colorimetric chemosensor for Hg²⁺ based on 1,2-diaminoanthraquinone was investigated. 1,2-Diaminoanthraquinone showed color change only with Hg²⁺, but it showed no significant changes upon addition of other metal ions such as Fe³⁺, Na⁺, Mg²⁺, Pb²⁺, Cd²⁺, Ni²⁺, Cu²⁺ and Zn²⁺. The solvatochromic responses of the 1,2-diaminoanthraquinone in several solvents of widely different polarities were measured; positive solvatochromism, with a large bathochromic shift, was observed from toluene to DMSO.

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