Nanofiber assemblies have been attractive materials for many engineering and medical applications because of their large surface area to volume ratio and unique porous structure. This study has demonstrated the concept that nanofiber assemblies can be used as receptor for Infrared Spectroscopy (FT-IR). In this study, Nylon 66 nanofiber assemblies with different thickness and fiber diameters were prepared via electrospinning method. The assemblies' thickness and the average fiber diameters vary in a range of 1-15 μm and 80-360 nm, respectively. The transmittancy and the adsorptive property to the targeted material, Orutoran, were characterized by FT-IR. It was observed that fiber diameters pose a significant influence on the transmittancy of nanofiber assemblies relative to the thickness. The specific surface area of nanofiber assemblies was observed to increase by about 3 times when the average diameter of fibers decreased from 360 nm to 80 nm. In order to evaluate the adsorptive properties, calibration curves were obtained by FTIR at around 1000cm-1 wavenumber. The mass of the Orutoran detected, as calculated with PLS, was plotted against the mass of Orutoran as deposited on the receptors. High coefficient of correlation was obtained for nanofiber assemblies with transmittancy higher than 98% at 1000cm-1 and surface area larger than 20 cm2/g.
The demand for paper yarn has increased as a textile fabric because of its light weight and low static electricity. However, paper yarn wrinkles easily and its softness and stretching properties are low. So we attempted to improve the stretching property of paper yarn by the high-pressure steam method which could provide a shape memorization to cellulosic materials. The most suitable condition based on our finding was steaming at 170 °C for 2 min after soaking in 0.28 % NH3 aqueous solution. By this treatment, over 84 % of the number of twists of paper yarn was maintained while the strength decreased to 78 %. For the paper yarn twisted together with viscose rayon filament, the number of twists was maintained at 94 % at 120 °C for 2 min of steaming without pre-treatment while the strength decreased to 85 %. The most desirable stretching property was achieved by the multi-twisting at 400 r/m of ten paper yarns, followed by high-pressure steaming. X-ray diffraction and CP/MAS 13C-NMR revealed that the crystallinity was increased 2 %, and the width of cellulose micelle was much larger by high-pressure steaming. Iβ type rich crystals of Manila hemp cellulose were stable at the steaming condition, so little transformation of the crystal type was observed. However, the orientation of the crystal was slightly improved by high-pressure steaming. It was considered that the mechanism of permanent shape memorization was derived from some recombination of the hydrogen bonds in the crystal region. High-pressure steaming was effective in the shape memorization of cellulosic fabrics and then the method improved the stretching property of textile made of multi-twisted paper yarns.
In these years, the bag-filter in a dust collector of the waste incinerator is used widely to remove the toxic substance, for example toxic gas, dioxins and heavy metals included in the ash dust by passing through the filter cloth. In order to prevent the destroy of filter, it is necessary to establish the evaluation method of wear for bag-filter. In this study, evaluation methods of wear for bag-filter are proposed by using ferromagnetic particles and optical fiber. Using these evaluation methods, wear mechanism for bag-filter was discussed.
Adsorption behaviors against musty smells for the activated carbons produced from reed grass, Phragmites communis Trinius, and bamboo, Phyllostachys heterocycla, were investigated and their properties were compared with those for commercial activated carbons from coconut shell. The activated carbons from reed grass shows superior adsorption behavior against both 2-methylisoborneol (2-MIB) and geosmine which cause musty smells although BET surface areas for these activated carbons are in the almost same range. The mean pore diameter, however, for the activated carbon from reed grass is a little larger as compared with other carbons. It seems that the pore size for the activated carbon from reed grass is more suitable for the adsorption of 2-MIB and geosmine.