Advanced Materials Research Vol. 441

Abstract: The effect of enzyme treatment using neutral cellulase on the colour fading property of cotton denim fabric manufactured by conventional ring-spun and torque-free ring-spun yarn was studied. Four cellulase processing parameters namely treatment temperature, treatment time, pH value and agitation were considered. In order to investigate the optimum condition for the neutral cellulsae treatment, an orthogonal analysis was used and, based on the colour fading percentage (CF%), the optimum condition for cellulase treatment on conventional ring-spun yarn made denim fabric was treatment temperature = 55°C; treatment time = 60 minutes; pH value = 8 and agitation = 100 steel balls (simulated vigorous agitation) for the best colour fading achievement with desired worn and aged effect. While the optimum condition for cellulase treatment on torque-free ring-spun made denim fabric was treatment temperature = 50°C; treatment time = 30 minutes; pH value = 8 and agitation = 50 steel balls (simulated mild agitation) for achieving best colour fading effect. Meanwhile, the level of importance based on the orthogonal analysis of the two types of fabric was not the same.

Abstract: To activate the surface of carbon fiber for better reinforced composites, the Xe₂^* excilamp was applied. The scanning electron microscopy (SEM) showed that the surface of Xe₂^* excilamp-treated carbon fibers was rougher than that of the control. X-ray photoelectron spectroscopy (XPS) analysis indicated that the Excilamp-treated fibers possessed more polar functional groups than the control fibers. After 2 min of irradiation, the wetting rate of treated carbon fibers in epoxy resin in balance increased by about 150% compared with the control, and the short-beam strength of carbon fiber/epoxy composites increased 6.6%.

Abstract: The hollow-triangle fiber is a novel profiled fiber. Its cross-sectional shape and shape factor index were obtained by a microcomputer image acquisition system, with a polarization capability and image analysis software. The shape factors of the fiber, such as shape factor in radius, shape factor in cross-section, branch factor and volume content were tested. The cross-section shape of cross-hollow fiber was compared with that of the hollow fiber. After that, a novel method about equivalent diameter was proposed to evaluate the characteristic shape coefficient. The method possesses many merits such as rapid, simple, accurate, convenient and thus being of great practical value.

Abstract: P-chloroaniline is one of the most important azo dye intermediates. It is a highly desired research on the identification of P-chloroaniline. Terahertz time domain spectroscopy (THz-TDS) is sensitive to the molecule structure of compound. In this paper, the spectra of P-chloroaniline located at the region from 0.1 to 3 THz were tested by THz-TDS system, and then the geometry structure of p-chloroaniline at the range of 0 THz to 10 THz was optimized, resonance frequency was calculated by Gussian03 software based on the density functional theory (DFT). The results showed that the absorbance peaks at 1.96 THz and 2.20 THz were caused by the hydrogen bonding force or crystal phonon mode, and suggested that it is feasible to identify P-chloroaniline by THz-TDS, which is of great value to the examination of banned azo dyes in the future.

Abstract: The focus of this study is to investigate the effect of cellulase enzyme treatment of the pulp on the reduction of energy consumption and the physical strength of old corrugated containers (OCC) fibers. Different cellulase samples including Novozyme Fibercare R, Novozyme Fibercare U and Novozyme Fibercare D used to improve the pulp beatability and physical strength of OCC fibers were comparatively studied. The effects of different cellulase samples on the breaking length and bursting index of paper were investigated. It was shown that Novozyme Fibercare D was proved to be the suitable cellulase sample used in the pretreatment of OCC fibers. It could become possible that the energy consumption of pulp beating reduced by 33.3% and the breaking length and bursting index of paper sheets increased by 50% when OCC fibers were dealt with Novozyme Fibercare D.

Abstract: In this paper, the effect of the charge of hydrophilic and lipophilic nanosized TiO₂ on the optical properties and printability of coated paper was investigated. The parameters including brightness, opacity, surface strength and sizing degree were used to evaluate the optical properties and printability of coated paper. The effects of hydrophilic and lipophilic TiO₂ on the properties of coated paper were discussed. It was shown that the optical properties and printability of coated paper increase persistently with the change of nanosized TiO₂ charged from 5% to 15%. Once the charge of nanosized TiO₂ was over 15%, the main properties of coated paper took on a downward tendency. The properties of coated paper were related to the surface properties of nanosized TiO₂ samples. It was found that the lipophilicity of nanosized TiO₂ sample played a more important role in the improvement of the coated paper properties, which was believed to be based on the fact that lipophilic nanosized TiO₂ could be well compatible with the binders used in the paper coating.

Abstract: This paper reports an attempt to prepare nanocrystalline cellulose from bamboo fibers through an enzymatic hydrolysis process. A type of commercial cellulase, viz. enzyme Cclast (mainly containing endoglucanase) was used in the preparation process. The morphology of the prepared bamboo cellulose nanocrystals was characterized by transmission electron microscopy (TEM) and the sugar analyses of hydrolysis residues were analyzed by ion chromatography (IC). The degree of polymerization (DP) was tested by automatic viscosimeter. All nanocrystalline cellulose from bamboo fibers presented a rod-like shape, an average diameter (D) of 5.3 nm and length (L) of 221 nm, with an aspect ratio (L/D) of around 42. It was shown that the use of enzymatic hydrolysis treatment to bleach bamboo pulp helps the preparation of well individualized rod-like nanocrystalline cellulose.

Abstract: In this work a study on the feasibility of extracting cellulose nanofibers from bamboo fibers, by means of three different procedures was carried out. These processes included the using of three different types of acids (H₂SO₄, HCl, and a mixture of H₂SO₄/HCl). The raw bamboo fibers were mercerized with NaOH solutions. They were then submitted to the three different acid hydrolysis processes. The final bamboo nanofibers were morphologically characterized by transmission electron microscopy (TEM) and their surface charges in suspensions were estimated by Zeta-potential. Their degree of polymerization (DP) was characterized by viscometry and the crystallinity was tested by X-ray diffraction (XRD). All bamboo nanofibers presented a rod-like shape, an average diameter (D) of 6-10 nm and length (L) of 100-180 nm, with an aspect ratio (L/D) of around 16-18. The aggregation state increases with the amount of HCl introduced into the extraction, due to the decrease of surface charges. However, this release presented nanofibers with litter better degree of polymerization than those whose acid hydrolysis was carried out using only H₂SO₄.

Abstract: The producing method of oil absorbent felt using recycled polyester bottle flakes is discussed, emphasizing on processes parameters such as dryness, filtration, spinning technique, drawing ratio, and etc.

Abstract: The purpose of this paper was to study the structure and the physical properties of jade fiber including morphological structure, crystallinity, moisture absorption, tensile property, electrostatic performance and thermal property.