Yazar "Hadimani, R. L." seçeneğine göre listele

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    Continuous production of piezoelectric PVDF fibre for e-textile applications
    (Iop Publishing Ltd, 2013) Hadimani, R. L.; Vatansever Bayramol, Derman; Sion, N.; Shah, Tahir H.; Qian, Limin; Shi, Shaoxin; Siores, Elias
    Polymers have been widely used as piezoelectric materials in the form of films and bulk materials but there are limited publications on piezoelectric fibre structures. In this paper the process of preparing piezoelectric polyvinylidene fluoride (PVDF) fibres from granules by continuous melt extrusion and in-line poling is reported for the first time. The poling of PVDF fibres was carried out at an extension ratio of 4:1, a temperature of 80 degrees C and a high voltage of the order of 13 000 V on a 0.5 mm diameter fibre in a melt extruder. The entire process of making PVDF fibres from granules and poling them to make piezoelectric fibres was carried out in a continuous process using a customized melt extruder. The prepared piezoelectric fibres were then tested using an impact test rig to show the generation of voltage upon application of an impact load. PVDF granules, unpoled fibres and poled fibres were examined by Fourier transform infrared spectroscopy (FTIR) which showed the presence of beta phase in the poled fibres. The ultimate tensile stress and strain, Young's modulus and microstructures of poled and unpoled fibres were investigated using a scanning electron microscope (SEM).
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    Effect of Addition of Multiwalled Carbon Nanotubes on the Piezoelectric Properties of Polypropylene Filaments
    (Amer Scientific Publishers, 2015) Vatansever Bayramol, Derman; Soin, Navneet; Hadimani, R. L.; Shah, Tahir H.; Siores, Elias
    The effect of addition of multiwalled carbon nanotubes (CNTs) on the piezoelectric properties of polypropylene (PP) monofilaments has been investigated. Various amounts of CNTs (0%, 0.01%, 0.1% and 1% weight ratios) were melt-blended with PP and the resulting nanocomposites were extruded in a continuous process with simultaneous on-line poling to produce monofilaments. Concurrent stretching at a draw ratio of 5:1 and polarisation at applied electric fields of 15 kV of PP/CNT filaments was observed to enhance the piezoelectric properties. The microstructure and crystallinity of the filaments was analysed using scanning electron microscopy (SEM), differential scanning calorimetric (DSC) and Fourier transform infrared spectroscopy (FTIR) techniques. Voltage generation by the CNT-modified PP filaments was determined by the application of predetermined load impact. The results show that the incorporation of CNTs in the PP fibre structure has a considerable impact on the enhancement of piezoelectric properties of the PP filament obtained that the peak voltage generation was almost four fold (from 0.76 V to 2.92 V) when 0.1 wt% of CNTs added into the polymer. This is owing to the fact that carbon nanotubes act as nucleating agent for enhancing the crystallisation during the melt extrusion process.