Elaheh Esmaeili - Academia.edu (original) (raw)

Papers by Elaheh Esmaeili

How to cite this article Rounaghi S. A, Esmaeil E. A Comparative Study of the Synthesis and Therm... more How to cite this article Rounaghi S. A, Esmaeil E. A Comparative Study of the Synthesis and Thermal Stability of Nanostrucrured Al and Al-Mg Powders Fabricated by Mechanical Alloying Technique. Nanostructured Al and Al-Mg (Mg 30 wt. %) powders with the mean crystallite sizes of 42 and 11 nm were prepared through the solid state ball milling technique. The milling process was performed for various times up to 12 h in argon atmosphere and the synthesized powders were in detail characterized by different techniques. The effect of milling time and Mg addition on the size, morphology, chemical composition, phase structure and crystallite size of the powder particles were thoroughly investigated and the results were compared with the non-alloyed Al system. Two distinct particle morphologies comprising lamellar flakes and solid granules were obtained as final milling products in Al and Al-Mg systems, respectively. It was revealed that Mg atoms gradually diffuse into the Al lattice during m...

How to cite this article Esmaeili E., Deymeh F, Rounaghi S. A., Synthesis and characterization of... more How to cite this article Esmaeili E., Deymeh F, Rounaghi S. A., Synthesis and characterization of the electrospun fibers prepared from waste polymeric materials. Int. Abstract Recently, the demands for the production of many different types of plastic wastes are greatly growing that subsequently, lead to the serious challenges in environmental considerations. Since, these materials are rarely resolved by microorganisms, hence, their recycling to the useful materials is crucial. In the present study, we used a solution electrospinning technique to synthesize nano/microfibers. SEM and FTIR analyses were performed for characterization of the prepared samples. The investigations obviously confirmed the formation of nano/microfibers of polyethylene terephthalate (PET), polystyrene (PS) and polycarbonate (PC) from the related waste plastics. To investigate the effect of various operational parameters of electrospinning method, the effect of the used needle diameter and voltage difference ...

international journal of nano dimension, 2015

In the current investigation, Fe3O4 water-based nanofluids were synthesized to examine the effect... more In the current investigation, Fe3O4 water-based nanofluids were synthesized to examine the effect of an alternative 3-D external magnetic field on its thermal behavioral pattern. A solvothermal method was used to prepare the magnetite nanoparticles. To characterize the nanoparticles, the study employed transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer and zeta-potential experiments. Vibrating sample magnetometer evaluations thoroughly confirmed the super-paramagnetic characteristics of the nanoparticles. Therefore, exposition of the resulting nanofluids to an AC external magnetic field led to the formation of aligned dipoles parallel to the applied field. Afterwards, the net magnetization in the absence of the external field was set to zero. Thermal measurements demonstrated an enhancement of convective heat transfer coefficients, particularly in the case of more diluted samples. The highest value of h was ass...

international journal of nano dimension, 2017

Recently, the demands for the production of many different types of plastic wastes are greatly gr... more Recently, the demands for the production of many different types of plastic wastes are greatly growing that subsequently, lead to the serious challenges in environmental considerations. Since, these materials are rarely resolved by microorganisms, hence, their recycling to the useful materials is crucial. In the present study, we used a solution electrospinning technique to synthesize nano/micro fibers. SEM and FTIR analyses were performed for characterization of the prepared samples. The investigations obviously confirmed the formation of nano/microfibers of polyethylene terephthalate (PET), polystyrene (PS) and polycarbonate (PC) from the related waste plastics. To investigate the effect of various operational parameters of electrospinning method, the effect of the used needle diameter and voltage difference was taken into consideration.

Journal of Nanostructures, 2017

Nanostructured Al and Al-Mg (Mg 30 wt. %) powders with the mean crystallite sizes of 42 and 11 nm... more Nanostructured Al and Al-Mg (Mg 30 wt. %) powders with the mean crystallite sizes of 42 and 11 nm were prepared through the solid state ball milling technique. The milling process was performed for various times up to 12 h in argon atmosphere and the synthesized powders were in detail characterized by different techniques. The effect of milling time and Mg addition on the size, morphology, chemical composition, phase structure and crystallite size of the powder particles were thoroughly investigated and the results were compared with the non-alloyed Al system. Two distinct particle morphologies comprising lamellar flakes and solid granules were obtained as final milling products in Al and Al-Mg systems, respectively. It was revealed that Mg atoms gradually diffuse into the Al lattice during milling and form a supersaturated Al-Mg solid solution (α phase). Thermal analyses of the powders revealed that metastable nanostructures formed during the milling transform into the equilibrium ...

In the current study, tin-promoted Pd/MWNTs synthesized via polyol pro-cess were developed. TEM i... more In the current study, tin-promoted Pd/MWNTs synthesized via polyol pro-cess were developed. TEM images evi-dences resulted in the formation of highly-dispersed Pd-Sn nanoparticles. The formation of Pd2Sn structural phase was confirmed by XRD and TPR techniques, composed mainly of inter-metallic species, supported by XPS re-sults. In this research, we applied in-termetallic-containing tin-promoted catalysts for the selective hydrogena-tion reaction of acetylene as the case study. The presence of a discontinuity in the Arrhenius plots could come from the kinetic factor as a result of change in acetylene coverage on Pd metallic ensembles. The intermetallic-containing assembled catalysts led to the good management of catalytic per-formance due to the creation of isolated adsorption sites on the catalyst surface, resulting in the higher ethylene selec-tivity.

Journal of Nanostructures, 2014

In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for ... more In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. TEM images showed a restricted distribution of nanoparticles in the range of 3-5 nm. The results indicated that nanoparticles sizes were resistant to further catalyst deactivation. XRD patterns signified alloying between Pd and Sn which contained a high percentage of ordered intermetallic structures (70.8%), as confirmed by XPS. According to the results, pore blocking and/or fouling was known as the main reasons of the catalyst deactivation. Here, we supposed a novel deactivation mechanism based on which dehydrogenation susceptibility of carbonaceous species (green oil) played a significant role in the formation of the isolated adsorption sites and then, catalyst deactivation.

In this research, SMFs panels were applied for further deposition of CNFs, ZnO and Al2O3 to hydro... more In this research, SMFs panels were applied for further deposition of CNFs, ZnO and Al2O3 to hydrogenate selectively acetylene to ethylene. To understand the role of different structures of the examined supports, the characterization methods of SEM, ASAP, NH3-TPD and N2 adsorption-desorption isotherms were used. Following the characterization of green oil by FTIR, the presence of more unsaturated constituents and then, more branched hydrocarbons formed upon the reaction over alumina-supported catalyst in comparison with the ones supported on CNFs and ZnO was confirmed, which in turn, could block the pores mouths. Besides the limited hydrogen transfer, the lowest pore diameters of Al2O3/SMFs close to the surface, supported by N2 adsorption-desorption isotherms could explain the fast deactivation of this catalyst, compared to the other ones.

Journal of Alloys and Compounds, Dec 1, 2017

Advanced Powder Technology, 2019

Abstract In the present study, aluminum nitride-carbon (AlN-C) nanocomposites are synthesized thr... more Abstract In the present study, aluminum nitride-carbon (AlN-C) nanocomposites are synthesized through a green, facile and inexpensive mechanochemical route. Well-dispersed nanofluids are prepared by milling of nanocomposite in ethylene glycol (EG) without using any surfactants/ dispersants. The resulting nanofluids have an excellent stability with no obvious sedimentation for at least three months. The results confirm the in-situ polymerization of EG on AlN surface and the formation of hyperbranched glycerol upon milling which in turn stabilizes the particles through a steric effect. The working nanofluids with very low loadings of up to 0.22 vol% of powder exhibit an enhanced heat transfer coefficient (h) of about 24% compared to that of the base fluid in a laminar flow regime (Re = 160). Brownian motion and boundary layer thinning are known as the main mechanisms, causing for this enhancement.

Journal of Alloys and Compounds, 2018

Journal of Alloys and Compounds, 2017

A versatile ball milling process was employed for the synthesis of hexagonal aluminum nitride (h-... more A versatile ball milling process was employed for the synthesis of hexagonal aluminum nitride (h-AlN) through the reaction of metallic aluminum with melamine. A combined experimental and theoretical study was carried out to evaluate the synthesized products. Milling intermediates and products were fully characterized via various techniques including XRD, FTIR, XPS, Raman and TEM. Moreover, a Boltzmann distribution model was proposed to investigate the effect of milling energy and reactant ratios on the thermodynamic stability and the proportion of different milling products. According to the results, the reaction mechanism and milling products were significantly influenced by the reactant ratio. The optimized condition for AlN synthesis was found to be at Al/M molar ratio of 6, where the final products were consisted of nanostructured AlN with average crystallite size of 11 nm and non-crystalline heterogeneous carbon.

Physical chemistry chemical physics : PCCP, Jan 17, 2017

Nowadays, the development of highly efficient routes for the low cost synthesis of nitrides is gr... more Nowadays, the development of highly efficient routes for the low cost synthesis of nitrides is greatly growing. Mechanochemical synthesis is one of those promising techniques which is conventionally employed for the synthesis of nitrides by long term milling of metallic elements under a pressurized N2 or NH3 atmosphere (A. Calka and J. I. Nikolov, Nanostruct. Mater., 1995, 6, 409-412). In the present study, we describe a versatile, room-temperature and low-cost mechanochemical process for the synthesis of nanostructured metal nitrides (MNs), carbonitrides (MCNs) and carbon nitride (CNx). Based on this technique, melamine as a solid nitrogen-containing organic compound (SNCOC) is ball milled with four different metal powders (Al, Ti, Cr and V) to produce nanostructured AlN, TiCxN1-x, CrCxN1-x, and VCxN1-x (x ∼ 0.05). Both theoretical and experimental techniques are implemented to determine the reaction intermediates, products, by-products and finally, the mechanism underling this syn...

Journal of Molecular Liquids, 2017

Abstract In this study, tris(hydroxymethyl)methane ammonium hydrogensulphate [(THA)(HSO4)] was sy... more Abstract In this study, tris(hydroxymethyl)methane ammonium hydrogensulphate [(THA)(HSO4)] was synthesized as the first nanoaliphatic ammonium-based ionic liquid via a simple chemical route in water. The [(THA)(HSO4)] ionic liquid was characterized by various techniques such as XRD, SEM, TEM, AFM, 1H NMR, 13C NMR, FT-IR, MS, TG, DTG and elemental analysis and successfully applied as an eco-friendly and recyclable catalyst for the synthesis of bis(indolyl)methane derivatives at room temperature under solvent-free conditions. Taking the environment and economy into consideration, the work presented here has the merits of environmental friendliness, high yields, simple work-up, easy operation and the avoidance of the organic solvents and inexpensive catalysts. In this work, some bis(indolyl)methane derivatives were synthesized and reported for the first time.

Applied Thermal Engineering, 2017

Advanced Research on Nanotechnology for Civil Engineering Applications

Nanotechnology refers to the understanding and manipulation of materials on the nanoscale (<10... more Nanotechnology refers to the understanding and manipulation of materials on the nanoscale (<100 nm). This can lead to marked changes in material properties and can result in improved performance and new functionality. Nanomaterials with properties such as corrosion resistance, and strength and durability are of particular interests to construction professionals, because, these properties directly affect the selection of construction materials, erection methods, and on-site handling techniques. Applying nanotechnology to construction, in some cases, may result in visionary and paradigm-breaking advances. The incorporation of nanomaterials can improve structural efficiency, durability and strength of cementitious materials and can thereby assist in improving the quality and longevity of structures. This chapter tries to analyze nanotechnology in the context of construction and explores the current scenario of nanotechnology in the construction industry. In order to identify the pot...

Chemical Engineering Communications, 2016

Fe3O4 nanoparticles were prepared through solvo-thermal method for further heat transfer applicat... more Fe3O4 nanoparticles were prepared through solvo-thermal method for further heat transfer applications. TEM, XRD, TGA, and VSM were applied to characterize the obtained nanoparticles. XRD pattern confirmed that nanoparticles were composed of 6-nm crystallites; however, TEM images showed the formation of ca. 75-nm highly dispersed magnetite clusters, made up of about 6-nm nanoparticles. Since, VSM analysis confirmed the superparamagnetic characteristics of Fe3O4 nanoclusters, heat transfer properties of the resulting nanofluids were studied to investigate the influence of the magnetic field on the behavior of the magnetite-based nanofluids. The findings indicated that the convective heat transfer coefficient increased up to 48% and 15%, respectively, for nanofluids containing 0.005 wt% magnetite particles dispersed in water and EG, when the frequency of the alternating magnetic field was changed from 50 Hz to 1 MHz. According to the results, compared to the water-based nanofluids, at higher field amplitudes, the h enhancements of EG-based ones were more pronounced, for instance, at H0 = 36,000 A/m, the h measurements are augmented by about 74% and 109%, respectively, compared to the water and EG as the base fluids. These findings could be explained by the use of specific lost powers of the nanofluids in the exposure of an external alternating magnetic field.

In the present study, PtRuCe/MWNTs nanocatalysts synthesized via polyol process technique are app... more In the present study, PtRuCe/MWNTs nanocatalysts synthesized via polyol process technique are applied as anode electro-catalyst in methanol electro-oxidation reaction (MOR). To characterize the nanocatalysts, TEM, XRD, EDS and XPS are investigated. Cyclic voltammetry and choronoamperometry are used to evaluate the electro-catalytic activity and stability of the catalysts in methanol electro-oxidation, respectively. Further addition of the Ce promoter to MWNTs-supported PtRu nanocatalyst shows the highest activity and the lowest onset potential in MOR at Ce to Pt molar ratio of 0.7. A significant enhancement of the forward anodic peak in cyclic voltammetry experiments is observed for the Ce-promoted PtRu catalyst with cerium to platinum molar ratio of 0.7, i.e. 349 mA/cm 2 .mg Pt , in comparison with 182 mA/cm 2 .mg Pt and 251 mA/cm 2 .mg Pt , respectively, corresponding to Pt/MWNTs and PtRu(1:1)/MWNTs nanocatalysts. Furthermore, the chronoamperommetry results present a remarkable improvement in the final current density of PtRuCe/MWNTs (6.1 mA/cm 2), compared to the un-promoted catalysts, having a decreasing propensity, i.e. PtRu/MWNTs (3.7 mA/cm 2) and Pt/MWNTs (2.05 mA/cm 2 .mgcat). The improved performance of PtRuCe/MWNTs may be attributed to the formation of highly-dispersed Pt nanoparticles on the support, followed by a significant enhancement of bifunctional mechanism, as a result of cerium incorporation.

Nanomaterials, 2021

The current investigation presents a green mechanochemical procedure for the synthesis of a speci... more The current investigation presents a green mechanochemical procedure for the synthesis of a special kind of rubber-compatible organo-montmorillonite (OMMT) for use in the inner liner compound of tires. The compatibility character of the OMMT arises from the mechanochemical reaction of the raw bentonite mineral and gum rosin as some of the organic constituents of the inner liner composition. The monitoring of OMMT synthesis by various characterization techniques reveals that gum rosin gradually intercalates into the montmorillonite (MMT) galleries during milling and increases the interlayer spacing to 41.1 ± 0.5 Å. The findings confirm the simultaneous formation of single- or few-layered OMMT platelets with average sizes from the sub-micron range up to several micrometers during the milling process. The mechanical properties of the OMMT/rubber nanocomposite, such as tensile strength, tear resistance and elongation, present a good enhancement in comparison to the un-modified material....

Journal of the European Ceramic Society, 2009

In this study, MgO nanoparticles were prepared by microwave-induced combustion synthesis of magne... more In this study, MgO nanoparticles were prepared by microwave-induced combustion synthesis of magnesium nitrate (as oxidant and MgO precursor) and polyethylene glycol and sorbitol as fuels. The effects of various parameters including the aging time of the ...

How to cite this article Rounaghi S. A, Esmaeil E. A Comparative Study of the Synthesis and Therm... more How to cite this article Rounaghi S. A, Esmaeil E. A Comparative Study of the Synthesis and Thermal Stability of Nanostrucrured Al and Al-Mg Powders Fabricated by Mechanical Alloying Technique. Nanostructured Al and Al-Mg (Mg 30 wt. %) powders with the mean crystallite sizes of 42 and 11 nm were prepared through the solid state ball milling technique. The milling process was performed for various times up to 12 h in argon atmosphere and the synthesized powders were in detail characterized by different techniques. The effect of milling time and Mg addition on the size, morphology, chemical composition, phase structure and crystallite size of the powder particles were thoroughly investigated and the results were compared with the non-alloyed Al system. Two distinct particle morphologies comprising lamellar flakes and solid granules were obtained as final milling products in Al and Al-Mg systems, respectively. It was revealed that Mg atoms gradually diffuse into the Al lattice during m...

How to cite this article Esmaeili E., Deymeh F, Rounaghi S. A., Synthesis and characterization of... more How to cite this article Esmaeili E., Deymeh F, Rounaghi S. A., Synthesis and characterization of the electrospun fibers prepared from waste polymeric materials. Int. Abstract Recently, the demands for the production of many different types of plastic wastes are greatly growing that subsequently, lead to the serious challenges in environmental considerations. Since, these materials are rarely resolved by microorganisms, hence, their recycling to the useful materials is crucial. In the present study, we used a solution electrospinning technique to synthesize nano/microfibers. SEM and FTIR analyses were performed for characterization of the prepared samples. The investigations obviously confirmed the formation of nano/microfibers of polyethylene terephthalate (PET), polystyrene (PS) and polycarbonate (PC) from the related waste plastics. To investigate the effect of various operational parameters of electrospinning method, the effect of the used needle diameter and voltage difference ...

international journal of nano dimension, 2015

In the current investigation, Fe3O4 water-based nanofluids were synthesized to examine the effect... more In the current investigation, Fe3O4 water-based nanofluids were synthesized to examine the effect of an alternative 3-D external magnetic field on its thermal behavioral pattern. A solvothermal method was used to prepare the magnetite nanoparticles. To characterize the nanoparticles, the study employed transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer and zeta-potential experiments. Vibrating sample magnetometer evaluations thoroughly confirmed the super-paramagnetic characteristics of the nanoparticles. Therefore, exposition of the resulting nanofluids to an AC external magnetic field led to the formation of aligned dipoles parallel to the applied field. Afterwards, the net magnetization in the absence of the external field was set to zero. Thermal measurements demonstrated an enhancement of convective heat transfer coefficients, particularly in the case of more diluted samples. The highest value of h was ass...

international journal of nano dimension, 2017

Recently, the demands for the production of many different types of plastic wastes are greatly gr... more Recently, the demands for the production of many different types of plastic wastes are greatly growing that subsequently, lead to the serious challenges in environmental considerations. Since, these materials are rarely resolved by microorganisms, hence, their recycling to the useful materials is crucial. In the present study, we used a solution electrospinning technique to synthesize nano/micro fibers. SEM and FTIR analyses were performed for characterization of the prepared samples. The investigations obviously confirmed the formation of nano/microfibers of polyethylene terephthalate (PET), polystyrene (PS) and polycarbonate (PC) from the related waste plastics. To investigate the effect of various operational parameters of electrospinning method, the effect of the used needle diameter and voltage difference was taken into consideration.

Journal of Nanostructures, 2017

Nanostructured Al and Al-Mg (Mg 30 wt. %) powders with the mean crystallite sizes of 42 and 11 nm... more Nanostructured Al and Al-Mg (Mg 30 wt. %) powders with the mean crystallite sizes of 42 and 11 nm were prepared through the solid state ball milling technique. The milling process was performed for various times up to 12 h in argon atmosphere and the synthesized powders were in detail characterized by different techniques. The effect of milling time and Mg addition on the size, morphology, chemical composition, phase structure and crystallite size of the powder particles were thoroughly investigated and the results were compared with the non-alloyed Al system. Two distinct particle morphologies comprising lamellar flakes and solid granules were obtained as final milling products in Al and Al-Mg systems, respectively. It was revealed that Mg atoms gradually diffuse into the Al lattice during milling and form a supersaturated Al-Mg solid solution (α phase). Thermal analyses of the powders revealed that metastable nanostructures formed during the milling transform into the equilibrium ...

In the current study, tin-promoted Pd/MWNTs synthesized via polyol pro-cess were developed. TEM i... more In the current study, tin-promoted Pd/MWNTs synthesized via polyol pro-cess were developed. TEM images evi-dences resulted in the formation of highly-dispersed Pd-Sn nanoparticles. The formation of Pd2Sn structural phase was confirmed by XRD and TPR techniques, composed mainly of inter-metallic species, supported by XPS re-sults. In this research, we applied in-termetallic-containing tin-promoted catalysts for the selective hydrogena-tion reaction of acetylene as the case study. The presence of a discontinuity in the Arrhenius plots could come from the kinetic factor as a result of change in acetylene coverage on Pd metallic ensembles. The intermetallic-containing assembled catalysts led to the good management of catalytic per-formance due to the creation of isolated adsorption sites on the catalyst surface, resulting in the higher ethylene selec-tivity.

Journal of Nanostructures, 2014

In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for ... more In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. TEM images showed a restricted distribution of nanoparticles in the range of 3-5 nm. The results indicated that nanoparticles sizes were resistant to further catalyst deactivation. XRD patterns signified alloying between Pd and Sn which contained a high percentage of ordered intermetallic structures (70.8%), as confirmed by XPS. According to the results, pore blocking and/or fouling was known as the main reasons of the catalyst deactivation. Here, we supposed a novel deactivation mechanism based on which dehydrogenation susceptibility of carbonaceous species (green oil) played a significant role in the formation of the isolated adsorption sites and then, catalyst deactivation.

In this research, SMFs panels were applied for further deposition of CNFs, ZnO and Al2O3 to hydro... more In this research, SMFs panels were applied for further deposition of CNFs, ZnO and Al2O3 to hydrogenate selectively acetylene to ethylene. To understand the role of different structures of the examined supports, the characterization methods of SEM, ASAP, NH3-TPD and N2 adsorption-desorption isotherms were used. Following the characterization of green oil by FTIR, the presence of more unsaturated constituents and then, more branched hydrocarbons formed upon the reaction over alumina-supported catalyst in comparison with the ones supported on CNFs and ZnO was confirmed, which in turn, could block the pores mouths. Besides the limited hydrogen transfer, the lowest pore diameters of Al2O3/SMFs close to the surface, supported by N2 adsorption-desorption isotherms could explain the fast deactivation of this catalyst, compared to the other ones.

Journal of Alloys and Compounds, Dec 1, 2017

Advanced Powder Technology, 2019

Abstract In the present study, aluminum nitride-carbon (AlN-C) nanocomposites are synthesized thr... more Abstract In the present study, aluminum nitride-carbon (AlN-C) nanocomposites are synthesized through a green, facile and inexpensive mechanochemical route. Well-dispersed nanofluids are prepared by milling of nanocomposite in ethylene glycol (EG) without using any surfactants/ dispersants. The resulting nanofluids have an excellent stability with no obvious sedimentation for at least three months. The results confirm the in-situ polymerization of EG on AlN surface and the formation of hyperbranched glycerol upon milling which in turn stabilizes the particles through a steric effect. The working nanofluids with very low loadings of up to 0.22 vol% of powder exhibit an enhanced heat transfer coefficient (h) of about 24% compared to that of the base fluid in a laminar flow regime (Re = 160). Brownian motion and boundary layer thinning are known as the main mechanisms, causing for this enhancement.

Journal of Alloys and Compounds, 2018

Journal of Alloys and Compounds, 2017

A versatile ball milling process was employed for the synthesis of hexagonal aluminum nitride (h-... more A versatile ball milling process was employed for the synthesis of hexagonal aluminum nitride (h-AlN) through the reaction of metallic aluminum with melamine. A combined experimental and theoretical study was carried out to evaluate the synthesized products. Milling intermediates and products were fully characterized via various techniques including XRD, FTIR, XPS, Raman and TEM. Moreover, a Boltzmann distribution model was proposed to investigate the effect of milling energy and reactant ratios on the thermodynamic stability and the proportion of different milling products. According to the results, the reaction mechanism and milling products were significantly influenced by the reactant ratio. The optimized condition for AlN synthesis was found to be at Al/M molar ratio of 6, where the final products were consisted of nanostructured AlN with average crystallite size of 11 nm and non-crystalline heterogeneous carbon.

Physical chemistry chemical physics : PCCP, Jan 17, 2017

Nowadays, the development of highly efficient routes for the low cost synthesis of nitrides is gr... more Nowadays, the development of highly efficient routes for the low cost synthesis of nitrides is greatly growing. Mechanochemical synthesis is one of those promising techniques which is conventionally employed for the synthesis of nitrides by long term milling of metallic elements under a pressurized N2 or NH3 atmosphere (A. Calka and J. I. Nikolov, Nanostruct. Mater., 1995, 6, 409-412). In the present study, we describe a versatile, room-temperature and low-cost mechanochemical process for the synthesis of nanostructured metal nitrides (MNs), carbonitrides (MCNs) and carbon nitride (CNx). Based on this technique, melamine as a solid nitrogen-containing organic compound (SNCOC) is ball milled with four different metal powders (Al, Ti, Cr and V) to produce nanostructured AlN, TiCxN1-x, CrCxN1-x, and VCxN1-x (x ∼ 0.05). Both theoretical and experimental techniques are implemented to determine the reaction intermediates, products, by-products and finally, the mechanism underling this syn...

Journal of Molecular Liquids, 2017

Abstract In this study, tris(hydroxymethyl)methane ammonium hydrogensulphate [(THA)(HSO4)] was sy... more Abstract In this study, tris(hydroxymethyl)methane ammonium hydrogensulphate [(THA)(HSO4)] was synthesized as the first nanoaliphatic ammonium-based ionic liquid via a simple chemical route in water. The [(THA)(HSO4)] ionic liquid was characterized by various techniques such as XRD, SEM, TEM, AFM, 1H NMR, 13C NMR, FT-IR, MS, TG, DTG and elemental analysis and successfully applied as an eco-friendly and recyclable catalyst for the synthesis of bis(indolyl)methane derivatives at room temperature under solvent-free conditions. Taking the environment and economy into consideration, the work presented here has the merits of environmental friendliness, high yields, simple work-up, easy operation and the avoidance of the organic solvents and inexpensive catalysts. In this work, some bis(indolyl)methane derivatives were synthesized and reported for the first time.

Applied Thermal Engineering, 2017

Advanced Research on Nanotechnology for Civil Engineering Applications

Nanotechnology refers to the understanding and manipulation of materials on the nanoscale (<10... more Nanotechnology refers to the understanding and manipulation of materials on the nanoscale (<100 nm). This can lead to marked changes in material properties and can result in improved performance and new functionality. Nanomaterials with properties such as corrosion resistance, and strength and durability are of particular interests to construction professionals, because, these properties directly affect the selection of construction materials, erection methods, and on-site handling techniques. Applying nanotechnology to construction, in some cases, may result in visionary and paradigm-breaking advances. The incorporation of nanomaterials can improve structural efficiency, durability and strength of cementitious materials and can thereby assist in improving the quality and longevity of structures. This chapter tries to analyze nanotechnology in the context of construction and explores the current scenario of nanotechnology in the construction industry. In order to identify the pot...

Chemical Engineering Communications, 2016

Fe3O4 nanoparticles were prepared through solvo-thermal method for further heat transfer applicat... more Fe3O4 nanoparticles were prepared through solvo-thermal method for further heat transfer applications. TEM, XRD, TGA, and VSM were applied to characterize the obtained nanoparticles. XRD pattern confirmed that nanoparticles were composed of 6-nm crystallites; however, TEM images showed the formation of ca. 75-nm highly dispersed magnetite clusters, made up of about 6-nm nanoparticles. Since, VSM analysis confirmed the superparamagnetic characteristics of Fe3O4 nanoclusters, heat transfer properties of the resulting nanofluids were studied to investigate the influence of the magnetic field on the behavior of the magnetite-based nanofluids. The findings indicated that the convective heat transfer coefficient increased up to 48% and 15%, respectively, for nanofluids containing 0.005 wt% magnetite particles dispersed in water and EG, when the frequency of the alternating magnetic field was changed from 50 Hz to 1 MHz. According to the results, compared to the water-based nanofluids, at higher field amplitudes, the h enhancements of EG-based ones were more pronounced, for instance, at H0 = 36,000 A/m, the h measurements are augmented by about 74% and 109%, respectively, compared to the water and EG as the base fluids. These findings could be explained by the use of specific lost powers of the nanofluids in the exposure of an external alternating magnetic field.

In the present study, PtRuCe/MWNTs nanocatalysts synthesized via polyol process technique are app... more In the present study, PtRuCe/MWNTs nanocatalysts synthesized via polyol process technique are applied as anode electro-catalyst in methanol electro-oxidation reaction (MOR). To characterize the nanocatalysts, TEM, XRD, EDS and XPS are investigated. Cyclic voltammetry and choronoamperometry are used to evaluate the electro-catalytic activity and stability of the catalysts in methanol electro-oxidation, respectively. Further addition of the Ce promoter to MWNTs-supported PtRu nanocatalyst shows the highest activity and the lowest onset potential in MOR at Ce to Pt molar ratio of 0.7. A significant enhancement of the forward anodic peak in cyclic voltammetry experiments is observed for the Ce-promoted PtRu catalyst with cerium to platinum molar ratio of 0.7, i.e. 349 mA/cm 2 .mg Pt , in comparison with 182 mA/cm 2 .mg Pt and 251 mA/cm 2 .mg Pt , respectively, corresponding to Pt/MWNTs and PtRu(1:1)/MWNTs nanocatalysts. Furthermore, the chronoamperommetry results present a remarkable improvement in the final current density of PtRuCe/MWNTs (6.1 mA/cm 2), compared to the un-promoted catalysts, having a decreasing propensity, i.e. PtRu/MWNTs (3.7 mA/cm 2) and Pt/MWNTs (2.05 mA/cm 2 .mgcat). The improved performance of PtRuCe/MWNTs may be attributed to the formation of highly-dispersed Pt nanoparticles on the support, followed by a significant enhancement of bifunctional mechanism, as a result of cerium incorporation.

Nanomaterials, 2021

The current investigation presents a green mechanochemical procedure for the synthesis of a speci... more The current investigation presents a green mechanochemical procedure for the synthesis of a special kind of rubber-compatible organo-montmorillonite (OMMT) for use in the inner liner compound of tires. The compatibility character of the OMMT arises from the mechanochemical reaction of the raw bentonite mineral and gum rosin as some of the organic constituents of the inner liner composition. The monitoring of OMMT synthesis by various characterization techniques reveals that gum rosin gradually intercalates into the montmorillonite (MMT) galleries during milling and increases the interlayer spacing to 41.1 ± 0.5 Å. The findings confirm the simultaneous formation of single- or few-layered OMMT platelets with average sizes from the sub-micron range up to several micrometers during the milling process. The mechanical properties of the OMMT/rubber nanocomposite, such as tensile strength, tear resistance and elongation, present a good enhancement in comparison to the un-modified material....

Journal of the European Ceramic Society, 2009

In this study, MgO nanoparticles were prepared by microwave-induced combustion synthesis of magne... more In this study, MgO nanoparticles were prepared by microwave-induced combustion synthesis of magnesium nitrate (as oxidant and MgO precursor) and polyethylene glycol and sorbitol as fuels. The effects of various parameters including the aging time of the ...