2024-03-28T21:25:10Z
https://jpst.irost.ir/?_action=export&rf=summon&issue=19
Journal of Particle Science and Technology
JPST
2423-4087
2423-4087
2015
1
1
Investigating the effects of chemical modification of clay nanoparticles on thermal degradation and mechanical properties of TPU/nanoclay composites
Mostafa
Gholami
Gity
Mir Mohamad Sadeghi
Thermoplastic polyurethane (TPU)/clay nanocomposites were prepared via a melt-compounding method using ester type TPU and two different modified organoclays (Cloisite 30B and Cloisite 15A) in different contents. The Effects of the chemical structure and content of the nanoclays on the thermal degradation and mechanical properties of TPU were also investigated. The effect of structural modification on dispersion during melt compounding has been studied by XRD and FTIR analysis. Barrier effect formation and thermal stability in both nanocomposites containing different nanoparticle content have been studied. The effect of chemical modification of the nanoparticles on mechanical properties in all contents has been investigated. The XRD results show that better dispersion near the exfoliated structure obtained for cloisite 30B is due to good interaction via hydrogen bonding between the TPU chains and layered silicate. A high content of the nanoparticles leads to disordering of soft and hard segments in the TPU chains, which is confirmed by FTIR. Mechanical properties analysis shows that the TPU/Cloisite 30B nanocomposites have higher modulus and tensile strength as well as elongation at break by the addition of 2% in both cloisite 30B (C30B) and cloisite 15A (C15A) than other contents of nanoclays.
Thermal degradation
Polyurethanes
Nanocomposite
Nanoclay particles
Chemical structure
2015
01
30
1
11
https://jpst.irost.ir/article_64_d2bad5730eabbce6dd03fbc27a30abde.pdf
Journal of Particle Science and Technology
JPST
2423-4087
2423-4087
2015
1
1
Kinetic Modeling of the High Temperature Water Gas Shift Reaction on a Novel Fe-Cr Nanocatalyst by Using Various Kinetic Mechanisms
Seyed Mahdi
Latifi
Mohamad Amin
Ghotbi Ravandi
In this work the kinetic data demanded for kinetic modeling were obtained in temperatures 350, 400, 450 and 500 oC by conducting experimentations on a Fe-Cr nanocatalyst prepared from a novel method and a commercial Fe-Cr-Cu one. The collected data were subjected to kinetic modeling by using two models derived from redox and associative mechanisms as well as an empirical one. The coefficients obtained for H2O reduction to H2 was much higher than those resulted for CO oxidation to CO2. In addition, the rate of H2O adsorption was shown to be greater than that of the CO adsorption on the catalyst surface in various temperatures. The activation energy of the novel catalyst calculated from the empirical model constants was lower than that of the commercial one.
water gas shift reaction
Fe-Cr nanocatalyst
kinetic modeling
associative and redox mechanisms
Activation energy
2015
01
30
13
19
https://jpst.irost.ir/article_65_38e99ea3c4b1a1aef04b86f294e8858d.pdf
Journal of Particle Science and Technology
JPST
2423-4087
2423-4087
2015
1
1
Preparation of Gd2O3 nanoparticles from a new precursor and their catalytic activity for electrochemical reduction of CO2 to CO
Mohammad Taghi
Behnamfar
The mononuclear Gd(III) complex, [Gd(L)3(H2O)5] (where L is alizarin yellow R (NaC13H8N3O5)), has been prepared in H2O under reflux condition. The Gd(III) complex has been characterized by elemental analysis and spectroscopic methods (UV–Vis and FT–IR). The Gd2O3 nanoparticles were prepared by the calcination of the Gd(III) complex in air at different temperatures up to 600 °C for 2 h. The calcination temperature was the key parameter which was changed for more investigation. The products were characterized by various methods such as FT–IR, X-ray diffraction analysis and field-emission scanning electron microscopy (FE–SEM). The electrochemical studies of the Gd(III) complex and Gd2O3 nanoparticles were performed in acetonitrile. The voltammograms in the absence and presence of carbon dioxide indicate that [Gd(L)3(H2O)5] and Gd2O3 nanoparticles can catalyze the electrochemical reduction of CO2 to CO.
Gd(III) complex
Gd2O3 nanoparticles
CO2 reduction
Cyclic voltammetry
alizarin yellow R
2015
01
30
21
30
https://jpst.irost.ir/article_75_9521cdf90efa01eb81f71d0d12b3495f.pdf
Journal of Particle Science and Technology
JPST
2423-4087
2423-4087
2015
1
1
Synthesis, structural characterization and catalytic activity of TiO2/Al2O3 photo-composite
Mohammad
Pakmehr
Abolghasem
Nourmohammadi
Majid
Ghashang
Ali
Saffar Teluri
In recent years, the effects of heterogeneous catalysts for the oxidation of organic and inorganic pollutants in industrial wastewaters are spread. Traditionally, these reactions are usually carried out using suspensions of photo-catalysts such as TiO2. A chemical method including TiCl4, Al(NO3)3, ethanol amine, ethyl acetoacetate and aqueous ammonia were used for the fabrication of TiO2-Al2O3 nano-composite. The as prepared nano-composite was characterized applying the XRD, FE-SEM and TEM techniques. The photocatalytic behavior of TiO2-Al2O3 nano-composite was evaluated in the photo-catalytic degradation of methyl orange under UV irradiation technique. The effect of various parameters including catalyst dosage, dyes concentration, pH and temperature on the degradation of methyl orange was investigated. The degradation rate was efficiently increased as the concentration of catalyst was decreased. The optimum dosage of methyl orange was found to be 10 mgL-1. In addition, we found that pH can significantly enhance the photocatalytic degradation of methyl orange dye.
TiO2-Al2O3 nano-composite
TiO2
Al2O3
Photocatalytic degradation
Methyl orange
2015
01
30
31
38
https://jpst.irost.ir/article_76_afa968ee7827e4aad0afba3da4588a49.pdf
Journal of Particle Science and Technology
JPST
2423-4087
2423-4087
2015
1
1
Effective Parameters on the Phase Morphology and Mechanical Properties of PP/PET/SEBS Ternary Polymer Blends
Omid
Moini Jazani
Mohammad Ali
Khoramabadi
Mohammad Mahdi
Salehi
Hossein
Riazi
Fariba
Soltanokottabi
In this work, ternary polymer blends based on polypropylene (PP)/ polyethylene terephthalate (PET) /poly(styrene-b (ethylene-co-butylene)-b-styrene) (SEBS) triblock copolymer and a reactive maleic anhydride grafted SEBS (SEBS-g-MAH) at various compositions were prepared by co-rotating twin screw extruder. The effects of PET, SEBS and SEBS-g-MAH compatibilizer on morphology of the blends were examined by scanning electron microscopy (SEM). The blends morphology was also estimated by some predicting methods, however, SEM results revealed some contrasts between results of predicting methods and the real morphology. Population of individual and core-shell particles as well as average diameter of the rubber-based cavities is extremely dependent on SEBS, SEBS-g-MA and PET content. Mechanical inspection tests showed that in comparison with the pure PP, addition of SEBS/SEBS-MA causes an increase in the impact strength of the system. Keeping other parameters constant, with increase in SEBS rubbery phase, the core-shell morphology was affected and the impact strength increased consequently. On the other hand, increase in PET content results in modulus increase and the impact strength decrease. Finally, the optimum processing conditions for compounding ternary PP/PET/SEBS blends were achieved.
Ternary Blend
morphology
mechanical properties
PP/PET/SEBS
2015
01
30
39
48
https://jpst.irost.ir/article_77_e6a6c37c498743a23d461c3a8a4318a3.pdf
Journal of Particle Science and Technology
JPST
2423-4087
2423-4087
2015
1
1
Xenon and krypton separation in a chromatographic column packed with granulated nano NaY zeolite
Mohammad
Kazemeini
Amir
Charkhi
Seyyed Javad
Ahmadi
In order to investigate the gas separation ability of a column packed with nanozeolitic material, nano NaY zeolite was synthesized and granulated. These uniform granules packed in a chromatographic column were utilized for separation of Xe and Kr under various operating conditions. With regards to the response peaks obtained from trace injections of Xe and Kr into the column, the first and second normalized moments of peaks were calculated. Moreover, the height equivalent to a theoretical plate (HETP) for the column was determined. The results illustrated that the retention time of Xe was remarkably greater than Kr indicating that, the nano NaY zeolite was a good choice as an adsorbent in Kr and Xe separation process. Moreover, a simple and temperature dependent correlation was derived to predict the HETP for the packed column. Ultimately, the calculated HETP values were in a good agreement with experimental data.
nano NaY zeolite
Xe and Kr
separation
packed column
2015
01
30
49
55
https://jpst.irost.ir/article_78_ac6c5bbd6aca940d7da47f60a8783af9.pdf
Journal of Particle Science and Technology
JPST
2423-4087
2423-4087
2015
1
1
Effect of Radiation Heat Loss and Ventilation on Dust Explosions in Spherical Vessels
Mehdi
Bidabadi
Abazar
Vahdat Azad
The flame propagation through a coal dust-air mixture in a spherical vessel was studied by means of a one-dimensional, Arrhenius-type kinetics and quasi-steady model. The model includes the evaporation of the volatile matter of dust particles into a known gaseous fuel (methane) and the single-stage reaction of the gas-phase combustion. Effect of venting devices as safety idea and the radiation heat loss, as very affecting phenomenon on flame propagation speed, flame temperature and pressure were studied. The radiation heat losses occur between the reaction zone and the surrounding wall. Influence of dust concentration and dust volatility on dust explosion parameters has been analyzed. The pressure-time curves that are generated with this model show a good similarity with those measured in practice. The model can represent a useful framework to be employed in organic dust combustion. This research can be valuable in the development of alternative fuels; and it can be used by the fire safety and control industry.
Dust Explosion
Spherical Flame
Coal Dust
Flame Speed
2015
01
30
57
64
https://jpst.irost.ir/article_79_0efb42d95abff20f848b5de936a099d0.pdf