Rayon fibers containing a titanium oxide photocatalyst were prepared to examine their dye decomposition effect. Although irradiation with ultraviolet rays caused no dye decomposition when the fibers were placed in air, the irradiation readily caused dye decomposition when the fibers were placed in an aqueous dye solution. The hygroscopicity of fibers was subsequently studied to find how it affects the dye decomposition effect of fibers. Little dye decomposition effect was found when titanium oxide was added to polypropylene, which is not hygroscopic at all. The result seems to show that, because the fiber material, which completely lacks hygroscopicity, kept the aqueous dye solution from being absorbed by the fibers to prevent reactions between dye molecules and titanium oxide particles imbedded inside the fibers.

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Excellent antibacterial properties and self cleaning performance have been reported for rayon fibers containing titanium oxide silica complex photocatalyst. However, when these fibers are dyed, photocatalysis may also decompose the dye. In this study, a direct dye and a reactive dye were used to dye these fibers in order to examine the dye fading of the dyed these fibers. First, the dyed these fibers were subjected to UV irradiation in air. Neither the direct dye nor the reactive dye faded at all and the color hue of the dyed these fibers was very stable to ultraviolet light. Subsequently, the dyed these fibers were subjected to UV irradiation in water. Although both dyes were found to fade, the direct dye faded more readily than the reactive dye. The difference was more pronounced when these fibers were dyed in light colors. The difference was believed to show up because cellulose molecules making up rayon fibers bond with direct dye molecules through hydrogen bonds whereas cellulose molecules bond with reactive dye molecules through covalent bonds. Finally, to examine the photocatalytic function of the dyed rayon fibers containing titanium oxide silica complex photocatalyst, the dyed these fibers were subjected to UV irradiation while immersed in an methylene blue aqueous solution. Methylene blue underwent dye decomposition, showing that the dyed these fibers maintained an adequate photocatalytic function.

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This study aims to clarify the effects of deoxyribonucleic acid (DNA) processed knitted fabric on human skin activity. We used two kinds of DNA, that is, the nucleoprotein extracted from salmon milt and the oligoDNA treated nucleoprotein with enzyme. The oligoDNA contains over 85% DNA. To determine the effects of oligoDNA application, the first experiment was a direct application method that applied an aqueous solution of oligoDNA powder directly to the inside of the upper arm for 14 weeks. The condition of the skin, measured by the water content of the skin, water evaporation from skin, tensile recovery, the microscope images of the replicas of skin surface and subjective feeling showed good results. Therefore, the second experiment applied the oligoDNA by using fabric. Arm bands were made of the knitted fabric processed with the oligoDNA solution and wearing tests were conducted. But this processed fabric was not useful. So, we used the nucleoprotein instead of the oligoDNA and modified the concentration of the solution. The nucleoprotein contains about 40% of DNA and about 60% of protamine. The results showed that the condition of human skin was affected by the modified processed fabric. The effects of the processed fabric on the skin condition were found in the water content of the skin, tensile recovery and the microscope images of the replicas of skin surface after four weeks had passed.

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In order to investigate the acoustical properties of hemp fibre, we measured the sound absorption coefficients of scutched and degummed hemp fibres, and compared it with other fibres using the standing wave ratio method. The effects of the thickness and bulk density of fibre assembly, the air gap behind fibre web and the diameter of fibre on the sound absorption coefficient were studied. The structural changes in hemp fibres were characterized by scanning electron microscope (SEM), Fourier transform Infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). It was found that the sound absorption coefficients increased with increasing the thickness, bulk density and air gap of scutched hemp fibre assembly in the range of 125-2000 Hz, but decreased with the increase of fibre diameter, respectively. The sound absorption properties were greatly improved when scutched hemp fibres were degummed because of the separation of fibre bundles.

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