فهرست مطالب

Journal of Particle Science and Technology
Volume:5 Issue: 2, Summer 2019

  • تاریخ انتشار: 1398/12/20
  • تعداد عناوین: 6
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  • Hamid Moghadam *, Mozhgan Zakeri, Abdolreza Samimi Pages 71-76
    Graphical size distribution is widely used in different fields of science and studies related to powders, droplets, bubbles, and pores. However, in some condition it may also be necessary to express the size distribution quantitatively. In spite of there being several suggested ways to quantify size distribution in the literature, some of these approaches are not applicable for many methods and the rest have other drawbacks. In this study, first, some quantitative size distribution methods (such as the polydispersity index) and their defects are concisely discussed. SPAN seems to be the most generally appropriate method, its parameters are determined from cumulative size distribution data. Nevertheless, some specific results imply that there are still some drawbacks in this method. Next, a new quantitative description of size distribution is presented which is applicable to many different techniques. In this method the characterization value is limited to 0 and 1, where 0 is related to completely polydispersed size distribution and 1 denotes the completely monodispersed size distribution.
    Keywords: quantitative size distribution, SPAN, polydispersity
  • Shohreh Saffarzadeh Matin *, Maryam Khandan, Anvar Shalmashi Pages 77-90

    In the present work, Iranian natural zeolite particles (NZ) as an abundant and low-cost resource were modified by chemical covalent attachments of commercially available stearic acid (SA) with tunable hydrophobic/hydrophilic properties. The versatile, simple, and green technique of mechanogriding was performed for the hydrophobic derivatisation of NZ. The NZ and as-prepared modified particles were thoroughly characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), Barret-Joyner-Halenda (BJH), and static water contact angle (WCA) measurements. TG-DTA results revealed the high thermal stability of the modified sample up to 490°C. The flake-like structures of functionalized NZ were discrete and no longer aggregated due to modification. The absorbing function of the modified NZ was evaluated by its removal of oil from a stable crude oil emulsion in water.

    Keywords: Hydrophobic modification, Mechanogrinding, Solventless modification, Natural Zeolite, Adsorption, Wastewater treatment
  • Hanieh Panahi *, Saeid Asadi Pages 91-99
    A good nano coating depends on the quality of the collision and spreading behavior of the nanoparticles. Unfortunately, in many cases, nanoparticle spreading data has not been recorded. In this paper, we have extended the evaluation model to predict the unavailable or censored maximum spreading diameter of nanoparticle data. Different point and interval methods have been considered for this problem. Choosing Bayesian evaluation, the Markov Chain Monte Carlo (MCMC) has been proposed as an efficient procedure for estimating the predictive inference for future observation. An important implication of the present study is that the censored maximum diameter data can be predicted well using the proposed methods. Results showed the proposed point predictions are close to real data, the predictive intervals contain the real values, and it verifies the applicability of the prediction techniques for real problems.
    Keywords: Censored Data, Classical, Bayesian prediction, Generalized inverted exponential model, Maximum diameter, nanoparticle
  • Ali Farahani, Arsalan Parvareh *, Mostafa Keshavarz Moraveji, Davood Soudbar Pages 101-108
    The effects of adding nanoclay to improve the thermal and mechanical properties of polypropylene (PP) copolymers grade (EPD60R) used in the pipe industry were investigated. To improve the dispersion of the nanoclay in the polymeric matrix, a 30 wt%  of nanoclay master batch was first prepared by mixing PP matrix maleic anhydride PP oligomer (PP-g-MA) and Cloisite® 15A (C15A) nanoclay. The prepared master batch was used to produce nanocomposites with 2 and 5 wt% nanoclay. The nanocomposites were analyzed by XRD (X-ray diffraction), SEM (Scanning electron microscopy), DSC (Differential scanning calorimetry), TGA (Thermogravimetric analysis), and other mechanical tests. The XRD and SEM results indicated the occurrence of an intercalated layer structure in the nanocomposites. Thermal properties of the nanocomposites were investigated using DSC and TGA tests. The crystallinity of the 2 wt% nanoclay was improved by about 59.23% in the nanoclay reinforced samples. As the content of nanoclay increased, the composite exhibited higher thermal degradation temperature. Performing a limiting oxygen index (LOI) test on the samples showed that the addition of nanoclay to the EPD60R matrix increased the flame retardancy by 12.58%. The tensile modulus of the nanocomposites was improved compared to the pure polymer, while the elongation at break and at yield showed a reduction. To investigate the nanocomposite in pipe application, a pipe (external diameter 110.8 and thickness 3.65 mm) was manufactured in a special tube extruder machine with 2 wt% of C15A.  Tests of the tube’s physical and mechanical properties indicated that its ring stiffness increased by 25% compared to the pure PP.
    Keywords: Melt mixing, Nanocomposite, Nanoclay, polypropylene, Ring stiffness
  • Rouzbeh Aghaei Hakkak, Maryam Ranjbar *, Sara Mirzaie Pages 109-116
    Zinc(II) ions play a special role in biological systems. Methionine is a sulphur containing amino acid with IUPAC name 2-amino-4-(methylthio)butanoic acid. In this study, ultrasonic synthesis and characterization of nanostructured Zn(II) methionine (Zn-Meth) in two different solvents were investigated. The reaction of ZnCl2 and methionine ligand under ultrasonic irradiation in both methanol and DMSO leads to the formation of nano-sized Zn(II) methionine complexes. Characterization of the Zn(II) complex was performed using elemental analysis, FT-IR spectroscopy, X-ray powder diffraction (XRD), thermal gravimetry (TGA), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS). The nano Zn-Meth complex, [Zn(CH3SCH2CH2CHNH2COOH)2]n, was then used as a precursor to obtaining the nano ZnO particle. An in-vitro study of the everted gut sac was also done on this complex to measure the uptake amount of zinc. The results showed that the nano-sized Zn-Meth has a higher absorption compared to its commercial and inorganic forms.
    Keywords: Amino acid nanostructures, Zn(II) complex, broiler chicken, ultrasonic synthesis, nano ZnO
  • Arezo Mohammadkhani, Azar Bagheri GH*, Saeed Rayati Pages 117-122

    In this study, we present an approach to synthesize Tl2O3 nanoparticles using a simple co-precipitation method that leads to the formation of X-shaped particles. The sample was characterized by XRD measurements, field emission scanning electron microscopy (FESEM), diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), and ultraviolet-visible (UV-VIS). The absorption spectrum of the sample showed that the optical band gap was 3.5 eV. The prepared photocatalyst was used in the photocatalytic degradation of Cephalexin (CPX) using irradiation, and the optimum parameters that were obtained were 0.2 g.L-1 of the photocatalyst at pH 5.5 and an irradiation time of 15 minutes.

    Keywords: Tl2O3, Cephalexin, Photocatalytic activity, Band gap, Co-precipitation method