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Liu Y.,Tianjin Polytechnic University | Zhao X.,Tianjin Polytechnic University | Zhao X.,Key Laboratory of Advanced Textile Composite Materials
Fibres and Textiles in Eastern Europe | Year: 2016

In this paper, the influence of fabric structure, weft density, end spacing and yarn fineness on the dielectric constant of polyester woven fabrics was studied. The results show that at low frequencies, the dielectric constant of fabric was clearly affected by the processing parameters; when the organisation of the fabric is plain i.e. the warp density is 140/10 cm, weft density 140/10 cm and yarn linear density 32 tex, the absorbing performance of polyester woven fabrics is at its best. At higher frequencies, the effect of the varying parameters on the dielectric constant of the fabrics can be neglected. Polyester woven fabrics have better EM absorbing properties for these parameters. This study offers a new theoretical basis for the development of EM absorptive fabrics. © 2016, Institute of Biopolymers and Chemical Fibres. All rights reserved.

Yu L.-H.,Tianjin Polytechnic University | Wang R.,Tianjin Polytechnic University | Wang R.,Key Laboratory of Advanced Textile Composite Materials | Xu L.,Tianjin Polytechnic University | Tao Q.,Tianjin Polytechnic University
Journal of Materials Science: Materials in Electronics | Year: 2016

Novel multi-walled carbon nanotubes (MWCNTs) and copper phthalocyanine (CuPc) modified conductive silver-plated fiber (MCA-fiber) was successfully prepared via chemical liquid deposition method with polyester as soft template. The structures and morphologies were characterized by X-ray photoelectron spectroscopy and field emission scanning electron microscopy. The binding energy of oxygen and carbon are 543, 296 eV respectively and the SEM images show CuPc and MWCNTs are deposited on the surface of silvered fiber continuously. The MCA-fiber is about 75 μm in diameter. The effect of process conditions on the properties of MCA-fiber was investigated. With the increasing of the concentration of AgNO3, the coating amount and electrical conductivity first increase and then decrease. The decrease of MWCNTs can bring down the electrical conductivity, but can improve the coating amount of materials on the surface of fibers. There is a sharp decrease from 7.20 × 10−4 to 1.33 × 10−4 s/cm when the MWCNT-doping content is 20 %. When the doping ratio of MWCNTs and CuPc is 2:8, the coating amount rises to 19.2 %. The mechanism study on the photovoltaic properties of MCA-fiber verifies that it can be used in fiber-shaped solar cells. © 2015, Springer Science+Business Media New York.

Yang W.,Tianjin Polytechnic University | Liu Y.,Tianjin Polytechnic University | Liu Y.,Key Laboratory of Advanced Textile Composite Materials | Liu Y.,Wuhan Textile University | And 4 more authors.
AIP Advances | Year: 2016

Needleless electrospinning technology is considered as a better avenue to produce nanofibrous materials at large scale, and electric field intensity and its distribution play an important role in controlling nanofiber diameter and quality of the nanofibrous web during electrospinning. In the current study, a novel needleless electrospinning method was proposed based on Von Koch curves of Fractal configuration, simulation and analysis on electric field intensity and distribution in the new electrospinning process were performed with Finite element analysis software, Comsol Multiphysics 4.4, based on linear and nonlinear Von Koch fractal curves (hereafter called fractal models). The result of simulation and analysis indicated that Second level fractal structure is the optimal linear electrospinning spinneret in terms of field intensity and uniformity. Further simulation and analysis showed that the circular type of Fractal spinneret has better field intensity and distribution compared to spiral type of Fractal spinneret in the nonlinear Fractal electrospinning technology. The electrospinning apparatus with the optimal Von Koch fractal spinneret was set up to verify the theoretical analysis results from Comsol simulation, achieving more uniform electric field distribution and lower energy cost, compared to the current needle and needleless electrospinning technologies. © 2016 Author(s).

Liu Y.,Tianjin Polytechnic University | Zhao X.,Tianjin Polytechnic University | Zhao X.,Key Laboratory of Advanced Textile Composite Materials | Tuo X.,Tianjin Polytechnic University
Journal of the Textile Institute | Year: 2015

The polyester knitted fabric was used as a basilicon carbide structure material. A three-layer composite coating finishing was applied to the structure material using ferrite, silicon carbide, and graphite absorbing materials. The single factor test method was used in this series of research. The impact on dielectric constant and loss tangent of absorbtion of each agent and the coating thickness of each layer were studied. From these results, the three-layer composite coating materials that had excellent absorbing properties were selected and prepared. The results showed that when the ferrite (60 wt%) was used as a bottom layer, the silicon carbide (36 wt%) was used as a middle layer and the graphite (24 wt%) was used as a surface layer with the respective thickness of 0.5, 0.3, and 0.3 mm, an excellent microwave absorbing property was noted for the three-layer composite coating material. In order to meet the requirements for the engineering field, physilicon carbideal and mechanical properties of the microwave absorbing materials were also characterized. © 2015 The Textile Institute

Liu Y.,Tianjin Polytechnic University | Zhao X.,Tianjin Polytechnic University | Zhao X.,Key Laboratory of Advanced Textile Composite Materials | Xiao T.,Tianjin Polytechnic University
Journal of the Textile Institute | Year: 2016

In this paper, plain woven fabric was selected as the base fabric. Graphite and silicon carbide were the surface layer and underlying layer absorbents, respectively. The influence of the content of the graphite and silicon carbide absorbent and coating thickness on the real part and the imaginary part of the dielectric constant, and the loss tangent are discussed. Through the optimization of electromagnetic parameters, graphite/silicon carbide double-coated polyester woven fabric absorbing materials with the best wave absorption performance were prepared. © 2016 The Textile Institute

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