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It was reported in our previous paper that the dispersion containing single cellulose nanofibers (= nanocellulose) was prepared from microbial cellulose pellicle using aqueous counter collision (ACC) method [1]. In this study, the nanocellulose has been investigated from the view point of a coating agent. Thus, various substrates such as a filter paper, polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP) films or sheets were coated with the nanocellulose, respectively. As a result for a hydrophilic substrate, both water and oil resistances on the surface of the nanofiber-coated filter paper were improved. On the other hand, coating with the same nanocellulose transformed the hydrophobic surface of PE, PET and PP sheets into the hydrophilic. This indicated that the nanocellulose, which was originated from microbial cellulose pellicle, had an effect switching surface properties depending on characteristics of substrates, differing from the wood cellulose nanofibers. Namely, the nanocellulose was preferably coated and adsorbed with the surface of substrates, whereas wood cellulose nanofibers prepared using ACC method and the homogenized pellicle did not accomplish such a behavior. Moreover, the dyeing as well as the improvement in water and oil resistances was performed simultaneously by coating using a mixture of nanocellulose with a dyeing agent. [ABSTRACT FROM AUTHOR]

Influence of ultraviolet irradiation on papers containing wasted tea leaves was studied. Ultraviolet irradiation generally caused reddish coloration. Irradiation under dry atmosphere caused stronger coloration than under ambient conditions. Presence of oxygen did not cause significant difference in coloration. Thin-layer chromatographic analysis showed disappearance of chlorophylls a and b, and did not disappearance of theaflavin by UV irradiation. The results strongly suggest that the coloration is caused by photochemical conversions of catechins to reactants (theaflavin-like compounds). [ABSTRACT FROM AUTHOR]

In the Antarctica during mid-summer being appropriate for a severe environment of UV-rays, the authors surveyed the protective effect of UV-cut materials against UV-rays, using a collagen sheet (hereafter "collagen artificial skin") that was covered with a UV-cut film and subjected to exposure outdoors. First, exposure of the laminated, collagen artificial skin not covered with any film to UV-rays caused the extracts from the 1st layer, i.e. the utmost outerlayer, of the collagen artificial skin to increase the terminal amino group concentration up to as high as 3.20 nmol/ml, since the collagen molecular chain was largely cut. On the other hand, for the 2nd and 3rd layers of the said sheet, the terminal amino group concentrations were found to have decreased in order, and for the 4th layer and onward, the concentrations were shown to have decreased down to 0.22 nmol/ml, which were nearly equal to the level before the exposure. Although the bands of three molecular chains of &alpha-, β-, and γ-chains in all samples after exposure to UV-rays were disappeared, it was also shown that the more a layer was inside, the less the collagen molecular chain was not dissolved. In addition, when the collagen artificial skin covered with a UV-blocking, zinc oxide-added film was exposed to the sunlight, it was demonstrated that the more the addition of zinc oxide in the film increased, the lower the terminal amino group concentration in the extracts from the exposed, collagen artificial skin was observed. At the time when the added quantity of zinc oxide reached 0.40v%, the concentration was maintained almost at the same level as observed prior to the exposure. Also in comparison with UV-protecting agents, it was shown that the film added with an organic compound acting as a UV-absorbing agent reduced most the damages sustained by UV-rays. As described above, the evaluation method using a collagen artificial skin could be effectively employed in outdoor exposure for examining the protective effect of UV-cut materials to the skin against the UV-rays in the Antarctica. [ABSTRACT FROM AUTHOR]

An attempt was made for the preparation of compounded papers using wasted tea leaves that could withstand repeated washing. Emulsion Polyamide-Epichlorohydrin copolymer was added as a binder to slurry containing crushed wasted tea leaves and hemp for paper making. When the resulting paper was measured for tensile strength under a wet condition, it was found markedly improved over a control paper without the emulsion. For instance, tensile strength was 2.1 N⋅m/g for a compounded paper containing 90 wt% hemp and 10 wt% wasted tea leaves but no binder, whereas the addition of the binder at 0.75 wt% improved tensile strength to 16.8 N⋅m/g. Compounded papers using wasted tea leaves were also very effective for deodorizing ammonia gas ; a paper containing a small amount, 10 wt%, of wasted tea leaves decreased the ratio of residual odor to 0.6 % in three hours. The addition of the binder was also found to keep the deodorization effect of the paper. Furthermore, a compounded paper using wasted tea leaves was repeatedly subjected to washing. The addition of the binder strikingly improved the washing durability of the paper that was subjected to washing repeatedly ; at an addition level of 0.75 wt%, the paper did not show any damage even after it was washed repeatedly 20 times. Further, the deodorization effect after washing was maintained. In fact, the ratio of residual order was very small at 2.1% or less in an hour even after the 20 times washing. [ABSTRACT FROM AUTHOR]

Various fiber materials were mixed with wasted tea leaves to attempt the preparation of new "KAMIKO" materials. When konjac pastes was applied to the surface of compounded papers using hemp and wasted tea leaves, the paper properties increased in tensile index, bursting index, and stiffness. On the other hand, konjac pastes application was found to increase the air permeance of the papers. Konjac pastes application was also found to extend time required for the papers to absorb water droplets, showing a decrease in water absorbency. Furthermore, when the papers were sewed on a machine, konjac pastes application was found to improve seam strength of the papers by about 20 N. Moreover, the papers with konjac pastes applied were tested for deodorization effect using ammonia gas. The result showed that the papers containing even a small amount, 10wt%, of wasted tea leaves exhibited an excellent deodorization effect and that konjac pastes application affected the effect very little. The results presented above showed that the use of hemp greatly improved mechanical properties of compounded papers using wasted tea leaves, whereas konjac pastes application also effectively improved the papers in seam strength. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Various studies were conducted to improve antibacterial properties of compounded papers using wasted green tealeaves prepared by a paper-making technique. The research included the elucidation of a cause of low antibacterial activity. Different binders and different degrees of grinding wasted tealeaves were tested with no effect on antibacterial properties of compounded papers using wasted green tealeaves. However, when a suspension of pulp and wasted tealeaves was air-dried and used to prepare a compounded paper, the compounded paper was found to have excellent antibacterial properties. The result indicated a cause for the low antibacterial activity of compounded papers using wasted green tealeaves prepared by the paper-making technique. That is, catechins abundant in wasted green tealeaves dissolved in water when ground and ran off with waste water during the paper-making process without settling in compounded papers. To confirm that, liquid from a mass-colloider used for wet-grinding wasted tealeaves was sampled and filtered. The filtrate was dropped onto a 100 wt% pulp paper. No viable bacterial cell was found in the pulp paper to which more than 1.0 ml/g of the filtrate was applied; the result showed that the liquid possessed good antibacterial properties. In other words, the liquid was confirmed to possess a high antibacterial activity. In paper making by the paper-making technique, aluminum sulfate was added to a suspension of pulp and ground, wasted tealeaves in order to readily settle catechins contained in liquid resulting from grinding wasted tealeaves in compounded papers using wasted tealeaves. The result revealed that a 2.70 wt% addition of aluminum sulfate to compounded papers using wasted green tealeaves improved antibacterial properties of the papers. [ABSTRACT FROM AUTHOR]

Wasted Green tea leaves were ground by different methods and papers containing the ground wasted Green tea leaves were prepared. The ground wasted Green tea leaves and the papers containing the ground wasted Green tea leaves were subjected to Scanning Electron Microscopy for morphological observation. The observation revealed that a mass-colloider ground wasted Green tea leaves to very thin films. As the clearance of the mass-colloider was widened from 40 µm to 150µm, the ground wasted Green tea leaves somewhat increased in thickness and turned into partially folded structures. In addition, after ground, the wasted Green tea leaves showed spiral vessels and vascular bundles extended into coil shapes by shear at the grinding. In contrast, wasted Green tea leaves ground with a bali mill were lumps ranging a few to 400 µm in size. The ground wasted Green tea leaves were used to prepare papers containing wasted Green tea leaves, which were observed. The observation revealed that papers containing wasted Green tea leaves ground with the mass-colloider had a layered structure in which the thin films of wasted Green tea leaves were layered in tight adhesion with networks of pulp fibers. In contrast, papers containing wasted Green tea leaves ground with the ball mill had a coarse structure in which lumps of the wasted Green tea leaves were buried in the network of pulp fibers. In addition, the papers containing wasted Green tea leaves ground by the two different methods were examined for tensile strength and bursting strength. The examination revealed little differences resulting from the different grinding methods, the mass-colloider and the ball mill, or from difference in the clearance of the mass-colloider. The result showed that the mechanical properties were mainly controlled by the pulp fibers in the papers containing wasted Green tea leaves and the wasted Green tea leaves made little contribution to the mechanical properties. On the other hand, papers containing wasted Green tea leaves were lower in stiffness than 100wt% pulp papers; especially papers containing wasted Green tea leaves ground with the ball mill were very soft. Furthermore, an examination of papers containing wasted Green tea leaves for permeability revealed that papers containing wasted Green tea leaves ground with the ball mill had much higher permeability than 100wt% pulp papers. [ABSTRACT FROM AUTHOR]

An attempt to develop a paper making method for a functional paper containing green tealeaves wastes disposed in industrial use was made. The authors successfully produced papers containing wasted green tealeaves ,not exceeding 60wt%, grounded by a mass-colloider. Antibacterial properties of these papers were investigated. Regarding the papers in a dry condition, the tensile index and bursting index were not significantly different depending on the kinds of tealeaves. The strength was decreased as increasing in the content of tealeaves. The tensile index of the papers were markedly lower in a wet condition when compared in a dry state. By addition of latex binder at a content of 0.3 wt%, the tensile index of the papers was 8.5-15.8 N-m/g in a wet condition for all kinds of the papers, which was similar to that for a paper made from 100 wt% pulp. Antibacterial test for Staphylococcus aureus was performed with various kinds of papers containing wasted tealeaves. Growth inhibition effects on the bacterium were noted in the papers containing wasted tealeaves, but not recognized in papers made from 100 wt% pulp. In particular, the antibacterial effects for a paper containing wasted black tealeaves were fairly high. It was demonstrated that the antibacterial effects were not reduced even by mixing a latex binder at 0.3 wt%. Further, the fiber assembled structure of the papers was observed by optical and scanning electron microscopes to be a multi-layered structure by stacking with a thin layer of pulps including the grounded tealeaves. These findings suggest that the tealeaves-containing papers with the unique layered structure can be a functional material for environmental friendly and sanitary usage. [ABSTRACT FROM AUTHOR]