Publications Scientifiques

Permanent URI for this communityhttps://dspace.univ-boumerdes.dz/handle/123456789/10

Browse

Author: search.filters.author.Benmebrouka, Hafsa

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Optimization of carbon nanotubes synthesis via pyrolysis over Ni/Al2O3 using response surface methodology
    (Taylor and Francis Online, 2021) Boufades, Djamila; Hammadou Née Mesdour, Souad; Moussiden, Anissa; Benmebrouka, Hafsa; Medjahdi, Ghouti; Kaddour, Omar
    Owing to the rapid expansion of preparing a low-cost and pure carbon nanotubes (CNTs) from large available raw materials as cheap carbon precursors and catalyst depositions via chemical vapor deposition process, Algerian condensate gas over Ni/Al2O3 was used in this study. Response surface methodology was utilized to assess and optimize the preparation parameters. Synthesis of CNTs was studied as a function of three independent parameters: catalyst/condensate-gas weight ratio (5–10 wt %), synthesis time (30-120 min) and temperature (700–1000 C). Optimum conditions for the CNTS-synthesis were found to be 5%, 112 min and 1000 C, for catalyst/condensate gas mass ratio, synthesis time and temperature, respectively. Under these conditions, Raman spectrum indicates high values of (IG/ID), which means high-quality CNTs. Examination by SEM and HRTEM revealed that the CNTs grown under optimum conditions had diameters of 10nm. The carbon yield predicted at the optimum process conditions was 81.76%. Conclusively, the pure and uniformed CNTs can be produced with high yield by the conversion of available-cheap resources via CVD-method. This method is practical, realistic, feasible in industrial scale and thus can reduces the cost manufacture of CNTs, which may help increase the impact of these remarkable materials in many fields.
  • No Thumbnail Available
    Item
    One-step synthesis and characterization of carbon nanospheres via natural gas condensate pyrolysis
    (Taylor and Francis, 2020) Boufades, Djamila; Hammadou Née Mesdour, Souad; Moussiden, Anissa; Benmebrouka, Hafsa; Hérold, Claire; Kaddour, Omar
    In the current work, carbon nanospheres (CNSs) were prepared via pyrolysis of gas condensate in N2 at 1273 K and atmospheric pressure for 2 h using ferric chloride as a catalyst precursor. X-ray diffraction, energy dispersive X-ray spectrometry (EDX) in scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectrometry (Raman), Fourier transform infrared spectroscopy, and thermal gravimetric analysis (TGA) are employed for the structural and morphological characterization of the nanomaterials formed. The conductivity of these films was measured using the four probe method. As results, SEM-EDX and TEM analysis reveal spherical shaped particles, with diameter varying between 100 and 200 nm and graphene interlayer distance of 0.339 nm. The very low ID/IG ratio obtained reveals a relatively low amount of disorder in the nanostructures and TGA analysis implies that thermal stability was achieved after 470 °C. Our work provides a simple synthetic strategy in one-step sample preparation of CNSs, which can be used for furfur applications such as high-performance supercapacitors or adsorbents
  • No Thumbnail Available
    Item
    Carbone nanospheres synthesis by pyrolysis of crude oil and optimization of parameters growth by response surface methodology (RSM)
    (Applied Chemistry, 2015) Boufades, Djamila; Pemanos Yelda, Bakoz; Mousidene, Anissa; Benmebrouka, Hafsa; Doumandji, Lotfi; Hamada, Boudjema
    Algerian oil as a new source of carbon is used to prepare the carbon nanospheres (CNSs) by pyrolysis method. A mixture of crude oil and FeCl3.6H2O solution as catalyst was injected into the reaction furnace to produce CNSs in an inert atmosphere, followed by multi step purification to remove different impurities. The carbon nanospheres have been characterized by scanning electron microscopy (SEM), energy dispersive X-rays spectroscopy (EDAX), X-ray diffraction(XRD), Raman spectroscopy and FTIRspectrum. The SEM image reveals that these CNSs have smooth surfaces and uniform particles with a diameter lower than 500 nm. the XRD and Raman studies shows that the graphitization degree of CNSs is not high , while the EDAX analysis shows that more than 98 % of the CNSs is carbon, FTIR proved the presence of new functions after samples treatment such as acid function. This study reports the optimization of various process parameters such as, temperature of reaction (860-940°C), process Time (90-150min)and mass ratio catalyst/Crude oil (0.83 10-3-2.4810-3 g/g) for increasing the Yield of CNSs. A MODDE 6.0 experimental design was employed for the optimization of synthesis of crude oil to ensure high production of carbon nanospheres in a low catalyst concentration and high temperature for a short length of time. The analysis of variance showed a high coefficient of determination value (R2 = 0.965) and Maximum CNSs production was predicted and experimentally validated, the optimized process conditions were identified to be reaction temperature of 900°C, duration synthesis of 113min and mass ratio catalyst /crude oil of 0.8 10-3 g/g with a yield of 13.23%