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Nurwaha D.,University of Burundi | Nurwaha D.,Higher Institute of Development | Wang X.,Donghua University | Wang X.,Key Laboratory of Science & Technology of Eco Textile
Fibers and Polymers | Year: 2015

In this study, three different free surface electrospinning methods: Splashing electrospinning, spiral coil electrospinning and rotary wires electrospinning methods were explored and compared in terms of fiber morphology (diameter fiber and its distribution) and process parameters. It was found that higher voltage values between 45 kV to 60 kV were necessary for Splashing electrospinning method while voltage values ranged between 50 kV to 70 kV and voltage values between 40 kV and 60 kV were enough for spiral coil and straight wires electrospinning methods, respectively. The real impact of process parameters and the evaluation of the influence of combined various processing parameters on electrospun fiber were undertaken. The results analysis demonstrates that two combined parameters based investigation can help provide insight into how to control and improve the design of the electrospinning process. The fiber diameter and its distribution can be effectively minimized either by controlling the processing parameters to a certain level. The nonlinearity relationship existing between electrospinning process parameters and nanofiber diameter and its distribution has been illustrated. It has also been observed that electric field plays a crucial role in the successful free surface electrospinning. © 2015, The Korean Fiber Society and Springer Science+Business Media Dordrecht. Source


Li Z.,Donghua University | Li Z.,Key Laboratory of Science & Technology of Eco Textile | Yu C.,Donghua University | Yu C.,Key Laboratory of Science & Technology of Eco Textile
Fibers and Polymers | Year: 2014

Ramie fiber is one of the natural cellulose fibers that have undergone rapid development due to its good performance. This study confirmed that hydrogen peroxide and isopropyl alcohol can be used as very efficient agents for simultaneous removal of non-cellulosic substances and improvement of ramie fiber properties. The factors influencing the properties of modified fiber with combined chemicals were investigated. Optimum treatment conditions were achieved at 85 °C, 60 min, pH 11.0, hydrogen peroxide concentration 7 %, and isopropyl alcohol concentration 4 %. SEM, XRD, and FT-IR were used to elucidate the effects of preparation and modification. Results showed that fiber preparation and chemical modification process in the same bath solution could successfully remove most of the gummy materials. The treated fibers demonstrated improved softness, elongation, and fineness properties as compared to the alkali or peroxide method. © 2014, The Korean Fiber Society and Springer Science+Business Media Dordrecht. Source


Li Z.,Donghua University | Li Z.,Key Laboratory of Science & Technology of Eco Textile | Yu C.,Donghua University | Yu C.,Key Laboratory of Science & Technology of Eco Textile
Journal of the Textile Institute | Year: 2015

Oxidation–reduction potential (ORP) was applied to monitor and control the oxidation reaction of peroxide hydrogen in the degumming process of ramie fibers. The effects of original pH, hydrogen peroxide dosage, oxidation temperature, and reaction time on ORP variations and fiber degumming efficiency were fully investigated. Central composite design method was used to optimize the degumming process. The optimum operating parameters were original pH 11.0, hydrogen peroxide dosage of 5.0 g/L, oxidation temperature of 85°C, and reaction time of 60 min, respectively. When the ORP value in the solution varied from +320 to +350 mV, it could achieve desired and reasonable degumming result. Under this range, the residual gum percentage of treated fibers was relatively lower and the mechanical property was better compared with other ORP values. This study could be instructive in online monitoring and control of ramie fiber preparation process using ORP as an indicating factor. © 2014 The Textile Institute. Source


Li Z.,Donghua University | Li Z.,Key Laboratory of Science & Technology of Eco Textile | Meng C.,Donghua University | Meng C.,Key Laboratory of Science & Technology of Eco Textile | And 2 more authors.
Textile Research Journal | Year: 2015

Oxidized cellulose can be produced from the oxidation reaction of hydrogen peroxide in the degumming process of ramie fibers. In this work, the contents of aldehyde and carboxylate groups in ramie cellulose which occurred during the degumming process were quantitatively determined by the electric conductivity titration method. The morphological changes and chemical components of oxidized cellulose were characterized using SEM, XRD, and FT-IR. Additionally, the relationship between the contents of the oxidized groups and the mechanical properties of the degummed fibers were discussed and analyzed. Results showed that the presence of aldehyde and carboxylate groups in the cellulose contributed significantly to the loss of tenacity, breaking elongation, softness, and degree of polymerization of degummed fibers. When the aldehyde content varied from 20 to 35 µmol/g and the carboxylate content varied from 140 to 180 µmol/g, respectively, raw fibers could achieve desired and reasonable degumming results. This study could offer useful information in obtaining optimal operation parameters for ramie oxidation degumming and better control of fiber quality. The degree of oxidation and content of oxidized cellulose could be used as effective indicating factors to demonstrate oxidation degumming efficiency and fiber properties. © 2015, © The Author(s) 2015. Source


Meng C.,Donghua University | Meng C.,Key Laboratory of Science & Technology of Eco Textile | Liu F.,Donghua University | Liu F.,Key Laboratory of Science & Technology of Eco Textile | And 5 more authors.
Textile Research Journal | Year: 2015

In this paper, anthraquinone was used to improve the properties of ramie fiber in oxidation degumming. The chemical components, structure properties, tensile properties of degummed fiber and the character of oxidation degumming solution were tested and analyzed. With the optimal dosage of anthraquinone (2% (o.w.f.)), the content of hemicellulose, the yield of degumming process, polymerization degree and the work of rupture of the degummed fiber were improved by 17.3%, 7%, 2% and 41%, respectively. The oxidation reduction potential (ORP) value of the degumming solution was also tested, with the addition of anthraquinone, and the ORP value decreased by 250 mV, which is of benefit for the properties of fiber. © 2015, © The Author(s) 2015. Source

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