Advanced Materials Research Vols. 821-822

Abstract: This work focuses on cellular toxicity of PET-based hollow fiber containing silver particles (Ag/PET hollow fiber), which was synthesized by different pressure method. Hela cells were used to investigate in vitro cytotoxicity of Ag/PET hollow fiber with the method of Methyl Thiazolyl Tetrazolium (MTT) assay. And the results showed no significant toxicity to Hela cells. And the SEM images of Hela cells treated by Ag/PET hollow fibers showed that cells morphology was unaltered in the present of Ag/PET hollow fiber. However, abnormal size, shrinkage and rounded appearance of cells at higher dose (20mg/ml)suggested slight toxicity of Ag/PET hollow fiber. Combining the antibacterial concentration (37.5μg/ml) in the pre-works, it was found that there was a certain concentration of silver ions which can achieve a minimization of cytotoxicity and a maximization of antibacterial efficacy.

Abstract: Optical reflective fiber has been widely used in protective clothing for road workers because of high-reflective effect which promised a strengthened visibility at night or in poor visibility. In this paper, four fibers with different cross section shape, i.e., round, triangle, rectangle and hollow pentagon, were melting spun from the transparent nylon which was analyzed and characterized previously. The spinning conditions were discussed in detail, and the hetercliteness of profiled fibers were also calculated. Both the reflectivity and brightness testing indicated that all profiled fibers showed the better reflective ability than the round one. Moreover, the mechanical, thermal and crystalline properties of round and triangle fibers after drawing were characterized.

Abstract: Cellulose, the most abundant materials in the plant resources, has been paid more attention. The updated technology of cellulose dissolution and the application of cellulose functional material were reviewed, especially the compounds of cellulose/inorganic (or organic) substance. The review is of benefit to the research in familiarizing with cellulose dissolution and its application.

Abstract: Kapok fiber has a unique large thin-walled hollow structure, lightweight and water repellent oil of excellent features, and is not yet fully exploited the small breed natural fibers. In the development process of the use of kapok fiber, there is a problem of dyeing, finishing, dyeing rate, dyeing and poor. Plasma processing technique is a modification to the fiber surface, non-polluting promising new technologies and has energy efficient. The research kapok fiber after plasma surface modification, found kapok modified staining rate has been significantly improved absorbent; Modified kapok fiber mechanical properties are not changed significantly; While exploring the plasma modified kapok fiber optimum.

Abstract: Plasticized polyacrylonitrile(PAN) fibers have been chemically impregnated with aqueous solution of KMnO₄ under varying conditions of temperature and time. The effect of modification conditions on the chemical structure and the mechanical properties of precursor fibers are characterized by wide-angle X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. The experimental results show that KMnO₄ can be used not only as catalyst for cyclization reaction, but also as plasticizer. The chemical modification between KMnO₄ and PAN can not occur below70°C, the most suitable condition for modification is performed at 80°C for 5 min.

Abstract: Color protective effects of honeysuckle extract, benzophenone-3, and non-ionic silicon emulsion to hair fibers were compared by measuring color change of hair exposed to UV irradiation. Dyed color fades faster than natural pigment of hair after sunlight irradiation. Experiment results indicate that honeysuckle extract prevented color fading of dyed red hair in 49.52% and virgin black hair in 19.35% due to its strong antioxidant ability, while color protection effect of benzophenone-3 is not obvious. Non-ionic silicone emulsion provided the best maintenance of hair color of 81.46% in dyed red hair and 41.94% in virgin black hair. However, the synergy of honeysuckle extract with non-ionic silicone emulsion for hair color protecting was not encouraged.

Abstract: Nanofiber nonwoven has been used in many fields due to the high surface area to volume ratio of the nanofibers and other extremely excellent properties. Nanofiber yarn, which is composed of long nanofiber with some twists for expanding nanofibers application, has been a challenging. A continuous nanofiber yarn was fabricated by a electrospinning technique with two oppositely charged spinnerets system in this work. The effect of process parameters such as applied voltage, the distance and the angle between the two spinnerets were examined in detail. The optimum parameters obtained included that the applied voltage was ±16kV, the distance and the angle between the two spinnerets were 8cm and 120o respectively. The nanofiber yarn has good potential applications in textile, medical, and biology.

Abstract: In this study, we have demonstrated that a rotating metal wire coil can be used as a nozzle to electrospin nanofibers on a large-scale. Without using any needles, the rotating wire coil, partially immersed in a polymer solution reservoir, can pick up a thin layer of charged polymer solution and generate a large number of nanofibers from the wire surface simultaneously. This arrangement significantly increases the nanofiber productivity. The fiber productivity was found to be determined by the coil dimensions, applied voltage and polymer concentration. The dependency of fiber diameter on the polymer concentration showed a similar trend to that for a conventional electrospinning system using a syringe needle nozzle, but the coil electrospun fibers were thinner with narrower diameter distribution. The profiles of electric field strength in the coil electrospinning was calculated and showed concentrated electric field intensity on the top wire surface.

Abstract: Mesopore activated carbons were prepared using hemp stem as feedstock by air-phosphoric acid activation method. The crystallite size of hemp stem-based mesoporous carbon is small, and its pores is larger. The phosphoric acid solution concentration has a signification effect on pore structure and adsorption property of mesopore activated carbons from hemp stem. The mesopore activated carbon attained at phosphoric acid solution concentration of 50% exhibits a maximum BET(Brunauer Emmett and Teller) specific surface area of 1351m²/g, total pore volume of 1.21 cm³/ g, mesopore pore volume of 0.90 cm³/ g and a mesopore fraction of 74.4%. And the resulting carbon has smaller crystal size, developed pore structure, wider pore size distribution.