Papers by Author: Qing Shan Kong

Abstract: In this paper, ferric alginate fibers was prepared by wet spinning of sodium alginate into a coagulating bath containing ferric chloride. The carbon-supported nanoscale zero-valent iron fibers (CSNZVIF) were obtained through thermal degradation of ferric alginate fiber at 900°Cunder N₂ atmosphere. The product was characterized by field emission scanning electron microscopy (FESEM), X-ray power diffractometer (XRD), and Brunauer-Emmett-Teller (BET) surface area. It was found that zerovalent iron particles were well dispersed in the amorphous carbon fibers. CSNZVIF has high surface areas of 352 m²/g. The existence of carboxylic group and hydroxyl group in ferric alginate structure unit plays key role in the formation of carbon-supported nanoscale zero-valent iron fibers. Fe³⁺ was reduced to Fe⁰ by hydroxyl group and as-formed amorphous carbon during heating under N₂. This thermal degradation and self-reduction reaction of ferric alginate fiber is potentially scalable to large production and continuous processing for preparing CSNZVIF.

Abstract: Schistose and aciculate CuO nanostructures have been synthesized by a novel ammonia assisted hydrothermal method of copper alginate. The conversion processes of copper alginate are investigated by thermogravimetrics (TG) analyses under N₂ and air atmosphere. The morphology, structure, and composition of the obtained CuO are investigated using SEM,TEM and XRD. It is found that different temperature and pH value resulted in the morphology and structure evolution of CuO. Ammonia was used as structure-directing agent in the hydrothermal system. The aggregation state of the nanostructures was controlled by the temperature. Dispersive schistose structures about 1μm in diameter were synthesized with 0.5mL ammonia at different temperatures. Dispersive microspheres of about 4 μm in diameter were also synthesized with 1 mL ammonia. Microspheres composed of nanoneedles and nanoplates were synthesized at 120°C and 160°C, respectively. Moreover, a possible growth mechanism governing the formation of such a nanomicrostructure was primarily discussed.

Abstract: In this study, biocompatible polymer poly(ethylene oxide) (PEO), gelation (denatured collagen) and nanometer silver colloid was added to the electrospinnning solution of alginate sodium to get anti-bacterial nanofiber mats. The morphology and mechanical properties of the electrospun mats have been investigated. Smooth fibers with diameters around 300 nm were obtained from 4.0 % solutions of varied alginate/PEO/gelation proportion. The anti-water property of the electrospun mats has been improved by crosslink with glutaraldehyde acetone solution and aqueous calcium chloride and ethanol.

Abstract: Alginate calcium fibers were prepared through wet spinning with good tensile strength which can be used for cloth materials. The morphology, mechanical property and combustion property of alginate calcium fibers were investigated. Blending yarns and textile of alginate calcium fibers and combed cotton was fabricated with good hand feeling and strength. Alginate salt fiber was prepared with wet spinning machine designed according to viscose fiber spinning machine. The diameter of alginate calcium fibers was about 10-15µm in diameter with smooth surface. The tensile strength of alginate salt fiber was larger than 4.8 cN in the dry state. The value of Limited Oxygen Index (LOI) of alginate calcium fibers was 34%. The average heat release rates (HRR) of the alginate fiber is about 21 kW/m2 which was much lower than that of most synthetic and natural fibers analysized with Cone. Alginate calcium fibers is an inherent flame-retardant fiber.