Please cite this article as: Xu, Y., Chen, X., Wang, Y., Yuan, Z., Stabbing r esistance of body ar mour panels impr egnated with shear thickening fluid, Composite Structures (2016), doi: http://dx.doi.org/10. 1016/ j.compstruct.2016.12.056 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Stabbing resistance of body armour panels impregnated with shear thickening fluid AbstractThis paper presents an investigation on the use of shear thickening fluid (STF) to improve stabbing resistance of soft ballistic body armour. STFs were produced from polyethylene glycol and silica nanoparticles. The effects of silica nanoparticle sizes and silica nanoparticle weight fraction were studied and STFs made with the different compositions were used to impregnate the Twaron ® woven fabrics. Systemic investigations into rheological behaviour of STF were carried out experimentally on STFs with different compositions. STF impregnated woven fabric panels were created and tested for stabbing resistance. Stabbing impact tests were conducted on 6 different types of STF impregnated fabric panels against 2 untreated fabric panels, and the results were studied against the benchmark fabrics without STF impregnation. Based on the same number of layers of fabric, the STF impregnation improves the stabbing resistance notably. For same panel areal density, the STF impregnated panels outperform the untreated fabric panel. The results of this research indicate the possibility of lighter ballistic panel materials for higher stabbing protection. It was also found that higher nanoparticle weight fraction and larger nanoparticle size of silica leads to better stabbing resistance performance among the STF impregnated panels.

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The film-forming ability and conductivity of graphitic carbon nitride (g-C 3 N 4 )a re still unsatisfying, despite much progressh aving been made in g-C 3 N 4 -related photocatalysts. Newm ethods for synthesizingg -C 3 N 4 films coupled with excellent conductive materials are of significance. Herein,afacile method for synthesizingn ovel carbonized polyvinylpyrrolidone (PVP)/g-C 3 N 4 (C PVP /g-C 3 N 4 )f ilms have been developed through an electrospinning technique. Nanocarbonsa re generated by in situ carbonization of PVP in the films, which could enhance the photoelectrochemical (PEC) performance of the films due to its good conductivity. The coverage of the C PVP /g-C 3 N 4 filmi sg ood and the films exhibit excellent PEC performance. Furthermore, the thickness of the films can be adjusted by varying the electrospinning time and substantially controlling the PEC performance, of which the photocurrentdensitiesunder visible-light irradiation are 3.55, 4.92, and 6.64 mAcm À2 with spinning times of 40, 70, and 120 min, respectively.T he photocurrent does not decreaseu ntil testinga t4 000 sa nd the coverage is still good after the tests,w hich indicates the good stabilityo f the films. The excellent PEC performance of the films and facile preparation method enables promising applicationsin energya nd environmental remediation areas.

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SnO2/graphitic carbon nitride (g-C3N4) composites were synthesized via a facile solid-state method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), thermogravimetry-differential thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), and N2 sorption. The results indicated that the composites possessed a two-dimensional (2-D) structure, and the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4 nanosheets. The gas-sensing performance of the samples to ethanol was tested, and the SnO2/g-C3N4 nanocomposite-based sensor exhibited admirable properties. The response value (Ra/Rg) of the SnO2/g-C3N4 nanocomposite with 10 wt % 2-D g-C3N4 content-based sensor to 500 ppm of ethanol was 550 at 300 °C. However, the response value of pure SnO2 was only 320. The high surface area of SnO2/g-C3N4-10 (140 m2·g−1) and the interaction between 2-D g-C3N4 and SnO2 could strongly affect the gas-sensing property.

Solution blow spinning (SBS) is an innovative process for spinning micro/nanofibers. In this paper, polyamic acid (PAA) nanofibers were fabricated via a SBS apparatus and then imidized into polyimide (PI) nanofibers via thermal process. The morphology and diameter distributions of PAA nanofibers were determined by scanning electron microscope (SEM) and Image Tool software, the processing parameters, including PAA concentration, solution feeding rate, gas pressure, nozzle size, and receiving distance were investigated in details. The fourier transform infrared spectroscopy (FTIR) was used to characterize the chemical changes in the nanofibers after thermal imidization. The results showed that the solution concentration exhibited a notable correlation with spinnability, and the formation of bead defects in PAA nanofibers. Solution feeding rate, gas pressure, nozzle size, and receiving distance affected nanofiber production efficiency and diameter distribution. The average diameters of fibers produced ranged from 129.6 to 197.7 nm by varying SBS parameters. Precisely, PAA nanofibers with good morphology were obtained and the average diameter of nanofibers was 178.2 nm with optimum process parameter. After thermal imidization, the PI nanofibers exhibited obvious adhesion morphology among interconnected fibers, with an increased average diameter of 209.1 nm. The tensile strength of resultant PI nanofiber mat was 12.95 MPa.

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To obtain excellent electromagnetic wave (EMW) absorption materials, the design of microstructures has been considered as an effective method to adjust EMW absorption performance. Owing to its inherent capability of effectively fabricating materials with complex various structures, three-dimensional (3D) printing technology has been regarded as a powerful tool to design EMW absorbers with plentiful microstructures for the adjustment of EMW absorption performance. In this work, five samples with various microstructures were prepared via fused deposition modeling (FDM). An analysis method combining theoretical simulation calculations with experimental measurements was adopted to investigate EMW absorbing properties of all samples. The wood-pile-structural sample possessed wider effective absorption bandwidth (EAB; reflection loss (RL) < − 10 dB, for over 90% microwave absorption) of 5.43 GHz and generated more absorption bands (C-band and Ku-band) as compared to the honeycomb-structural sample at the same thickness. Designing various microstructures via FDM proved to be a convenient and feasible method to fabricate absorbers with tunable EMW absorption properties, which provides a novel path for the preparation of EMW absorption materials with wider EAB and lower RL.