Dr Mehrnoush Khavarian

Dr Mehrnoush Khavarian

Casual Research Assistant

School of Architecture and Built Environment

Career Summary

Qualifications

  • Doctor of Philosophy, University of Science, Malaysia
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Publications

For publications that are currently unpublished or in-press, details are shown in italics.


Journal article (17 outputs)

Year Citation Altmetrics Link
2018 Kairi MI, Khavarian M, Bakar SA, Vigolo B, Mohamed AR, 'Recent trends in graphene materials synthesized by CVD with various carbon precursors', Journal of Materials Science, 53 851-879 (2018)

© 2017, Springer Science+Business Media, LLC. Graphene is a single layer of carbon atoms arranged in an sp2-hybridized structure with properties far superior compared to other mat... [more]

© 2017, Springer Science+Business Media, LLC. Graphene is a single layer of carbon atoms arranged in an sp2-hybridized structure with properties far superior compared to other materials. Research and development in graphene synthesis have been rapidly growing the past few years, especially using chemical vapor deposition (CVD) over various types of carbon precursor. The nature and the type of carbon precursor is one important parameter of growth by CVD, especially for graphene production, since they can dramatically impact graphene growth yield and rate. However, effects of the used carbon precursor on graphene growth mechanisms are rarely discussed. In the course of large-scale and low-cost graphene preparation, this review on the recent trends regarding the utilization of diverse carbon precursors used to synthesize graphene via the CVD method is of great interest for development of improved or alternative synthesis methods. The details and the mechanisms involved in graphene synthesis using carbon precursors in the form of gaseous, liquids and solids are compared, analyzed and discussed thoroughly. In this review, we present a thorough overview on the impact and mechanisms of carbon precursors in achieving high-quality graphene with competitive edge in the near future.

DOI 10.1007/s10853-017-1694-1
Citations Scopus - 2
Co-authors Mehrnoush Khavarian
2018 Kairi MI, Zuhan MKNM, Khavarian M, Vigolo B, Bakar SA, Mohamed AR, 'Co-synthesis of large-area graphene and syngas via CVD method from greenhouse gases', Materials Letters, 227 132-135 (2018)

© 2018 In this study, we report a novel and efficient way to produce large-area graphene and syngas simultaneously from CH4 and CO2 via CVD. The successful synthesis of syngas was... [more]

© 2018 In this study, we report a novel and efficient way to produce large-area graphene and syngas simultaneously from CH4 and CO2 via CVD. The successful synthesis of syngas was confirmed by online gas chromatography characterization whereas the graphene produced within the same process was verified using Raman spectroscopy, Raman mapping and HRTEM. This work helps to better understand graphene growth from CH4 and CO2 and improve the CVD method by providing a novel pathway for the synthesis of large-area graphene with a valued by-product. With our derived CVD approach, graphene was grown while producing syngas and consuming green-house gases which is of great importance in this current climate change phenomenon.

DOI 10.1016/j.matlet.2018.05.031
Co-authors Mehrnoush Khavarian
2018 Koh MK, Khavarian M, Chai SP, Mohamed AR, 'The morphological impact of siliceous porous carriers on copper-catalysts for selective direct CO

© 2018 Hydrogen Energy Publications LLC A series of copper-catalysts, Cu-ZnO-MnO (CZM), supported on morphologically distinct siliceous porous carriers (SBA-15, MCF, KIT-6) were s... [more]

© 2018 Hydrogen Energy Publications LLC A series of copper-catalysts, Cu-ZnO-MnO (CZM), supported on morphologically distinct siliceous porous carriers (SBA-15, MCF, KIT-6) were synthesized and applied in direct CO2 hydrogenation to methanol. The morphological impact of porous carriers on the formation and growth of copper crystallites and the molecular pore diffusion of the porous catalysts were investigated. Among the synthesized catalysts, KIT-6 supported catalyst (CZM/KIT-6) presented the most superior properties. The morphology of KIT-6 deterred mesopore plugging and favored the formation of small copper crystallites. CZM/KIT-6 also possessed greater resistance to copper crystallite growth and loss of copper surface area during reaction due to the pore-confining effect of the porous carrier and the larger inter-crystallites spacing among copper crystallites. The high effective diffusivity (catalyst pore-geometry dependent coefficient) of CO2 molecules in CZM/KIT-6 could indicate efficient transfer of reactant molecules to active sites and the removal of reaction products. The superior characteristics of CZM/KIT-6 contributed to the high CO2 conversion (8.2%) and high methanol production rate (105.3 mol/kgcat.h) at low reaction temperature (180 °C). The methanol selectivity attained was =99% in all the experiments.

DOI 10.1016/j.ijhydene.2018.03.202
Co-authors Mehrnoush Khavarian
2018 Sukri MFF, Khavarian M, Mohamed AR, 'Effect of cobalt loading on suppression of carbon formation in carbon dioxide reforming of methane over Co/MgO catalyst', Research on Chemical Intermediates, 44 2585-2605 (2018)

© 2018, Springer Science+Business Media B.V., part of Springer Nature. Carbon dioxide reforming of methane was studied over Co/MgO catalyst which was prepared by using the direct ... [more]

© 2018, Springer Science+Business Media B.V., part of Springer Nature. Carbon dioxide reforming of methane was studied over Co/MgO catalyst which was prepared by using the direct sol¿gel method with different Co loadings. The performance of Co/MgO catalyst was thoroughly investigated over methane (CH4) and carbon dioxide (CO2) conversions, CO and H2selectivity, syngas ratio (H2:CO) and the rate of carbon deposition. The rate of carbon deposition of Co/MgO catalyst decreased with the lower Co content, which resulted in the formation of small metal crystal size and well distribution. The rate of carbon deposition increased from 0.0016 to 0.2227¿gc/gcat¿h as the Co loadings of Co/MgO catalyst also increased from 10 to 25¿mol%. High Co loading formed a weak interaction and larger particles size that promoted the carbon deposition on Co/MgO catalyst during the reaction. The Co/MgO catalyst with 10¿mol% of Co loading posed the small particle sizes, which resulted in high CH4and CO2conversions of 80 and 86%, respectively, along with the lowest rate of carbon deposition after a 50¿h reaction time stream, which was enhanced via strong metal support interaction. Graphical Abstract: [Figure not available: see fulltext.].

DOI 10.1007/s11164-017-3248-1
Co-authors Mehrnoush Khavarian
2018 Hussien AA, Yusop NM, Abdullah MZ, Al-Nimr MA, Khavarian M, 'Study on convective heat transfer and pressure drop of MWCNTs/water nanofluid in mini-tube', Journal of Thermal Analysis and Calorimetry, 1-10 (2018)

© 2018 Akadémiai Kiadó, Budapest, Hungary In recent times, the use of multi-walled carbon nanotubes (MWCNTs)/water nanofluids as a coolant has garnered immense interest due to the... [more]

© 2018 Akadémiai Kiadó, Budapest, Hungary In recent times, the use of multi-walled carbon nanotubes (MWCNTs)/water nanofluids as a coolant has garnered immense interest due to their high thermal conductivity. Thus, this study investigates the effect of different mass fractions ((Formula presented.)) of MWCNTs (0.075, 0.125 and 0.25 mass%) on forced convection heat transfer. Uniform and stable nanofluids were prepared using the two-step method coupled with the addition of water-soluble polymer polyvinyl pyrrolidone (PVP) and using high-power probe sonicator. The test was carried out in a circular mini-tube (Din = 1.1 mm), which was heated uniformly to study the developing and fully developed laminar flow. The Reynolds number (Re) varied from 200 to 500. The heat transfer coefficient was found to be significantly enhanced with increase in mass fraction of MWCNTs in the prepared nanofluid. The maximum enhancement of heat transfer coefficient was 23.9% for the nanofluid prepared with 0.25 mass% of MWCNTs. The experimental result revealed an increase in friction factor using the MWCNTs/water nanofluid. A maximum pressure drop of 9.9% was achieved for the highest mass fraction of MWCNTs.

DOI 10.1007/s10973-018-7234-7
Co-authors Mehrnoush Khavarian
2018 Khairudin NF, Sukri MFF, Khavarian M, Mohamed AR, 'Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane', BEILSTEIN JOURNAL OF NANOTECHNOLOGY, 9 1162-1183 (2018)
DOI 10.3762/bjnano.9.108
Co-authors Mehrnoush Khavarian
2018 Anthonysamy SBI, Afandi SB, Khavarian M, Mohamed ARB, 'A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide', Beilstein Journal of Nanotechnology, 9 740-761 (2018)

© 2018 Anthonysamy et al. Various types of carbon-based and non-carbon-based catalyst supports for nitric oxide (NO) removal through selective catalytic reduction (SCR) with ammon... [more]

© 2018 Anthonysamy et al. Various types of carbon-based and non-carbon-based catalyst supports for nitric oxide (NO) removal through selective catalytic reduction (SCR) with ammonia are examined in this review. A number of carbon-based materials, such as carbon nanotubes (CNTs), activated carbon (AC), and graphene (GR) and non-carbon-based materials, such as Zeolite Socony Mobil-5 (ZSM-5), TiO2, and Al2O3 supported materials, were identified as the most up-to-date and recently used catalysts for the removal of NO gas. The main focus of this review is the study of catalyst preparation methods, as this is highly correlated to the behaviour of NO removal. The general mechanisms involved in the system, the Langmuir-Hinshelwood or Eley-Riedeal mechanism, are also discussed. Characterisation analysis affecting the surface and chemical structure of the catalyst is also detailed in this work. Finally, a few major conclusions are drawn and future directions for work on the advancement of the SCR-NH3 catalyst are suggested.

DOI 10.3762/bjnano.9.68
Co-authors Mehrnoush Khavarian
2017 Nizam MK, Sebastian D, Kairi MI, Khavarian M, Mohamed AR, 'Synthesis of graphene flakes over recovered copper etched in ammonium persulfate solution', Sains Malaysiana, 46 1039-1045 (2017)

The synthesis of high quality graphene via economic way is highly desirable for practical applications. In this study, graphene flake was successfully synthesized on Cu/MgO cataly... [more]

The synthesis of high quality graphene via economic way is highly desirable for practical applications. In this study, graphene flake was successfully synthesized on Cu/MgO catalyst derived from recovered Cu via etching in ammonium persulfate solution. Recovered Cu acted as efficient active metal in Cu/MgO catalyst with good crystal structure and composition according to XRD and XRF results. FESEM, EDX, HRTEM, Raman spectroscopy and SAED analysis were carried out on the synthesized graphene. The formation of single, bilayer and few layer of graphene from Cu/MgO catalyst derived from recovered Cu was feasible.

DOI 10.17576/jsm-2017-4607-05
Citations Scopus - 2
Co-authors Mehrnoush Khavarian
2017 Wong YJ, Koh MK, Khavarian M, Mohamed AR, 'Investigation on cobalt aluminate as an oxygen carrier catalyst for dry reforming of methane', International Journal of Hydrogen Energy, 42 28363-28376 (2017)

© 2017 Hydrogen Energy Publications LLC In this study, the catalytic performance of cobalt aluminate as an oxygen carrier catalyst was investigated in the dry reforming of methane... [more]

© 2017 Hydrogen Energy Publications LLC In this study, the catalytic performance of cobalt aluminate as an oxygen carrier catalyst was investigated in the dry reforming of methane (CH4). The series of cobalt aluminate with different cobalt (Co) content ranged between 18.32% and 45.85% were synthesized by the sol-gel method with aim of inducing the its ability as an oxygen carrier catalyst for dry reforming while suppressing the rate of carbon deposition. The reducibility of the developed catalysts corresponded with the initiation of CH4oxidation at reaction temperatures between 700 °C and 900 °C. Successive oxidation-reduction of CH4and carbon dioxide (CO2) invoked a novel reaction mechanism for the production of syngas through the reduction of the catalyst by CH4and regeneration with CO2. A stability test was conducted on the best performing cobalt aluminate catalyst with 33.33% of Co content. The result showed the sustainability of the catalyst for up to 30 h of continuous reaction with an average yield of hydrogen (H2) and carbon monoxide (CO) at 97.2% and 99.7%, respectively. The amount of CH4converted into deposited carbon was measured at approximately 1.9%. This current research on cobalt aluminate highlights the possibility of producing syngas through simultaneous oxidation-reduction of CH4and CO2.

DOI 10.1016/j.ijhydene.2017.09.151
Citations Scopus - 3
Co-authors Mehrnoush Khavarian
2015 Khavarian M, Chai SP, Mohamed AR, 'The effects of process parameters on carbon dioxide reforming of methane over Co-Mo-MgO/MWCNTs nanocomposite catalysts', Fuel, 158 129-138 (2015)

© 2015 Elsevier Ltd. All rights reserved. The activity of the nanocomposite catalysts comprising of as-synthesized multi-walled carbon nanotubes (MWCNTs) with Co-Mo/MgO was studie... [more]

© 2015 Elsevier Ltd. All rights reserved. The activity of the nanocomposite catalysts comprising of as-synthesized multi-walled carbon nanotubes (MWCNTs) with Co-Mo/MgO was studied on carbon dioxide (CO<inf>2</inf>) reforming of methane (CH<inf>4</inf>) (CRM) under various experimental conditions. The effects of reaction parameters such as hydrogen reduction, reaction temperature, CH<inf>4</inf>/CO<inf>2</inf> gas feed ratio and gas hourly space velocity (GHSV) on the performance of the Co-Mo-MgO/MWCNTs nanocomposite catalysts were thoroughly investigated from a few aspects such as the CO<inf>2</inf> and CH<inf>4</inf> conversions, syngas production and resistance towards carbon formation. After 10 h on the stream, CH<inf>4</inf> and CO<inf>2</inf> conversions of the nanocomposite catalyst decreased by only about 5%; whereas the Co-Mo/MgO catalyst was completely deactivated. Although the catalytic activity and syngas production were not significantly affected after hydrogen reduction, the rate of carbon deposits decreased significantly from 0.084 to 0.074 g<inf>c</inf>/g<inf>cat</inf> h. As the reaction temperature increased, the CH<inf>4</inf> and CO<inf>2</inf> conversions and H<inf>2</inf>/CO syngas ratio increased while the deposited carbons decreased. The catalytic activity and stability decreased with the GHSV due to coke deposition and other interfering side reaction effects. The reaction temperature of 950 °C at CO<inf>2</inf>/CH<inf>4</inf> ratio of unity was found to be the most appropriate process condition to produce a H<inf>2</inf>/CO syngas ratio of 1.1 with CH<inf>4</inf> and CO<inf>2</inf> conversions being 98.6% and 99.1% respectively.

DOI 10.1016/j.fuel.2015.05.021
Citations Scopus - 13
Co-authors Mehrnoush Khavarian
2014 Khavarian M, Chai SP, Mohamed AR, 'Direct use of as-synthesized multi-walled carbon nanotubes for carbon dioxide reforming of methane for producing synthesis gas', Chemical Engineering Journal, 257 200-208 (2014)

In this study, laboratory prepared multi-walled carbon nanotubes (MWCNTs) over Co-Mo/MgO catalysts were used as novel nanocomposite catalysts for carbon dioxide reforming of metha... [more]

In this study, laboratory prepared multi-walled carbon nanotubes (MWCNTs) over Co-Mo/MgO catalysts were used as novel nanocomposite catalysts for carbon dioxide reforming of methane (CRM). The influence of acid treatment process on the catalyst performance was thoroughly investigated. It was determined that Co-Mo/MgO present in the as-synthesized MWCNTs was responsible for high catalytic activity of the reforming reaction. The performance of the nanocomposite catalysts was compared with the conventional Co-Mo/MgO catalysts prepared by sol-gel method, revealing that MWCNTs played a supporting role in preventing catalyst deactivation. The nanocomposite catalysts gave CH4 and CO2 conversions of 97% and 98%, respectively, for the CRM reactions performed at 850°C with a GHSV of 120 L/h gcat and a CH4/CO2 ratio of 1 under atmospheric pressure. Stability tests, carbon deposition and characteristics of the nanocomposite catalysts were investigated up to 100 h of reaction. The proposed reaction mechanism for this catalyst shows that CH4 decomposition and carbon gasification by CO2 were the two important side-reactions. © 2014 Elsevier B.V. All rights reserved.

DOI 10.1016/j.cej.2014.05.079
Citations Scopus - 23
Co-authors Mehrnoush Khavarian
2013 Khavarian M, Chai SP, Mohamed AR, 'Carbon dioxide conversion over carbon-based nanocatalysts', Journal of Nanoscience and Nanotechnology, 13 4825-4837 (2013)

The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is kno... [more]

The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity. Copyright © 2013 American Scientific Publishers All rights reserved.

DOI 10.1166/jnn.2013.7569
Citations Scopus - 14
Co-authors Mehrnoush Khavarian
2013 Khavarian M, Chai SP, Tan SH, Mohamed AR, 'Effects of growth parameters on the morphology of aligned carbon nanotubes synthesized by floating catalyst and the growth model', Fullerenes Nanotubes and Carbon Nanostructures, 21 765-777 (2013)

Aligned carbon nanotubes (CNTs) were grown in a simple designed horizontal quartz tube reactor from chemical vapor deposition (CVD) using ferrocene as floating catalyst (FC). FC-C... [more]

Aligned carbon nanotubes (CNTs) were grown in a simple designed horizontal quartz tube reactor from chemical vapor deposition (CVD) using ferrocene as floating catalyst (FC). FC-CVD process was performed using methane as carbon source under nitrogen flow without introducing hydrogen. Aligned CNTs with an average length of ca. 10 µm were produced at reaction temperatures in a range of 950-1100°C and methane flow rate of 250-450 sccm for 60 minutes. The diameter of CNTs was influenced by the size of iron catalyst particles formed in the reactor. A conceptual model of CNT formation and its growth mechanism were proposed in this study. © 2013 Copyright Taylor and Francis Group, LLC.

DOI 10.1080/1536383X.2012.654544
Citations Scopus - 5
Co-authors Mehrnoush Khavarian
2011 Khavarian M, Chai SP, Huat Tan S, Mohamed AR, 'Effects of temperature on the synthesis of carbon nanotubes by FeCl 3 as a floating catalyst precursor', Fullerenes Nanotubes and Carbon Nanostructures, 19 575-583 (2011)

The influence of temperature on the growth of carbon nanotubes (CNTs) by chemical vapor deposition (CVD) using FeCl3as a floating catalyst (FC) precursor and methane as a carbon s... [more]

The influence of temperature on the growth of carbon nanotubes (CNTs) by chemical vapor deposition (CVD) using FeCl3as a floating catalyst (FC) precursor and methane as a carbon source was studied. FeCl3was found to be an efficient FC precursor for methane CVD into CNTs without the need of introducing hydrogen in feed. The optimum temperature for growing CNTs was 1050°C, giving off 80% yield of CNTs. The electron microscopy analysis shows that the produced CNTs possessed the average diameter of 30 nm and Raman scattering reveals the low ID/IGratio of 0.62, indicating the presence of high graphitized structure. Copyright © Taylor & Francis Group, LLC.

DOI 10.1080/1536383X.2010.504954
Citations Scopus - 3
Co-authors Mehrnoush Khavarian
2011 Khavanan M, Chai SP, Tan SH, Mohamed AR, 'Effect of different parameters on the morphology of carbon nanotubes structures grown by floating catalyst method', Journal of Applied Sciences, 11 2382-2387 (2011)

Carbon nanotubes (CNTs) were synthesized by a Floating Catalyst (FC) chemical vapor deposition (CVD) method in a horizontal reactor. This method led to achieve high yield synthesi... [more]

Carbon nanotubes (CNTs) were synthesized by a Floating Catalyst (FC) chemical vapor deposition (CVD) method in a horizontal reactor. This method led to achieve high yield synthesis of CNTs with controlled structure. Present study showed that iron (III) chloride hexahydrate (FeCl3. 6H20) was an efficient FC precursor for CVD of methane into CNTs. The effects of different process parameters such as reaction temperature and reaction time on the morphology of CNTs had been investigated. The deposited layers containing CNTs and CNFs were analyzed by the Transmission Electron Microscopy (TEM) and the yield of the as-grown nanotubes was investigated by the thermogravimetric analysis (TGA). © 2011 Asian Network for Scientific Information.

DOI 10.3923/jas.2011.2382.2387
Citations Scopus - 6
Co-authors Mehrnoush Khavarian
2010 Khavarian M, Chai SP, Tan SH, Mohamed AR, 'Iron (III) chloride as floating catalyst precursor to produce multi-walled carbon nanotubes from methane', Nano, 5 167-173 (2010)

Multi-walled carbon nanotubes (MWCNTs) were prepared by floating catalyst (FC) method, using methane as a carbon source and iron (III) chloride (FeCl3) as a catalyst precursor, fo... [more]

Multi-walled carbon nanotubes (MWCNTs) were prepared by floating catalyst (FC) method, using methane as a carbon source and iron (III) chloride (FeCl3) as a catalyst precursor, followed by purification with air oxidation and acid treatment. The as-grown and purified MWCNTs were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetry analysis and Raman spectroscopy. The average inner and outer diameters of the MWCNTs were 25 and 39 nm, respectively. The purity and yield of the purified MWCNTs were more than 92% and 71% weight fraction, respectively. © 2010 World Scientific Publishing Company.

DOI 10.1142/S1793292010002074
Citations Scopus - 4
Co-authors Mehrnoush Khavarian
2009 Khavarian M, Chai SP, Tan SH, Mohamed AR, 'Floating catalyst cvd synthesis of carbon nanotubes using iron (III) Chloride: Influences of the growth parameters', Nano, 4 359-366 (2009)

Carbon nanotubes (CNTs) were synthesized by a low-cost floating catalyst (FC) chemical vapor deposition (CVD) method in a horizontal reactor. It was found that iron (III) chloride... [more]

Carbon nanotubes (CNTs) were synthesized by a low-cost floating catalyst (FC) chemical vapor deposition (CVD) method in a horizontal reactor. It was found that iron (III) chloride (FeCl3) is a high efficient FC precursor for methane CVD to grow CNTs. In this study, the effects of reaction temperature and flow ratio of methane to nitrogen (CH4:N2) on the morphology of the CNTs were investigated. The morphological analysis by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that increasing the reaction temperature and flow ratio of CH 4:N2 grew CNTs of larger diameters. Energy dispersive X-ray (EDX) and thermogravimetric analysis (TGA) were employed to study the purity of the produced CNTs. As shown by the TGA, the highest yield of 74.19% was recorded for the CNTs grown at 1000°C and flow ratio CH 4:N2 of 300:200. © 2009 World Scientific Publishing Company.

DOI 10.1142/S1793292009001939
Citations Scopus - 8
Co-authors Mehrnoush Khavarian
Show 14 more journal articles

Conference (3 outputs)

Year Citation Altmetrics Link
2017 Yousefi A, Bunnori NM, Khavarian M, Hassanshahi O, Majid TA, 'Experimental investigation on effect of multi-walled carbon nanotubes concentration on flexural properties and microstructure of cement mortar composite', AIP Conference Proceedings (2017)

© 2017 Author(s). Multi-walled carbon nanotubes (MWCNTs) with extraordinary properties have shown a promising role toward enhancing the flexural performance of cement composites. ... [more]

© 2017 Author(s). Multi-walled carbon nanotubes (MWCNTs) with extraordinary properties have shown a promising role toward enhancing the flexural performance of cement composites. This paper investigates the effect of concentrations of MWCNTs on major flexural properties of cement mortar composites, including flexural strength, strain capacity, modulus of toughness, and modulus of elasticity. For this purpose, cement mortar reinforced with various concentrations of MWCNTs (0.02, 0.05, and 0.1 wt.% by weight of cement). Dispersion of MWCNTs was carried out using ultrasonic energy and concrete superplasticizer as surfactant agent. Prismatic beams of sizes 100 mm×100 mm×500 mm were fabricated and four-point bending tests were performed on the beam specimens at the age of 28 days. The results from bending tests indicated substantial improvements in the flexural strength, strain capacity and modulus of toughness of MWCNT-cement mortar, while the modules of elasticity remained constant. It was observed that specimens reinforced with 0.05 wt.% of MWCNTs exhibited higher flexural properties enhancement. Besides, it was noticed that with the increase of MWCNTs content, the flexural properties of MWCNT-cement mortar increased. The microstructure observation of MWCNT-cement mortar demonstrated well dispersion of nanotubes with concentration of 0.05 wt.% but large agglomerates and bundles of MWCNTs depicted within the sample with higher loading of MWCNTs (0.1 wt.%). It was concluded that the properties enhancement of MWCNT-cement composites highly depends on the concentration of MWCNTs and the level of dispersion of nanotubes in the cement matrix.

DOI 10.1063/1.5005663
Co-authors Mehrnoush Khavarian
2017 Khavarian M, Mohamed AR, 'Biogas reforming over multi walled carbon nanotubes with Co-Mo/MgO nanoparticles', AIP Conference Proceedings (2017)

© 2017 Author(s). The utilization of biogas for the production of valuable chemicals is among the very important processes in the energy research field. The most suitable process ... [more]

© 2017 Author(s). The utilization of biogas for the production of valuable chemicals is among the very important processes in the energy research field. The most suitable process for biogas reforming is dry reforming of methane. An obvious drawback is the variable composition of biogas rather than the stoichiometrically equimolar quantities of methane and carbon dioxide. Moreover, activating the methane and carbon dioxide molecules in the reforming reaction provides many challenges in exploring new concepts and opportunities for development of unique catalysts. In the present work, the catalytic activity behavior of Co-Mo-MgO/multi-walled carbon nanotubes (MWCNTs) nanocomposite in dry reforming was investigated with different CO2/CH4feed ratio to evaluate the performance of this catalyst for biogas reforming reaction. It was found that conversions of methane and carbon dioxide were greatly influenced by the feed gas ratio. The CH4and CO2conversions are 83 % and 87 % at the reaction temperature of 825 °C, GHSV of 175 L/h.gcat and CO2/CH4feed ratio of unity. The minimum carbon deposition rate is observed at the CO2/CH4feed ratio of 0.6 which is 0.080 gc/gcat-h.

DOI 10.1063/1.5010473
Co-authors Mehrnoush Khavarian
2013 Khavarian M, Mohamed AR, 'Effects of reaction temperature on CO

The utilization of greenhouse gases, such as carbon dioxide (CO2) and methane (CH4), is among the most important challenges in the energy research field. The catalytic activity be... [more]

The utilization of greenhouse gases, such as carbon dioxide (CO2) and methane (CH4), is among the most important challenges in the energy research field. The catalytic activity behavior of CO2 reforming of CH4 (CRM) over synthesized multi-walled carbon nanotubes (MWCNTs) with Co-Mo and MgO nanoparticles was investigated. Based on conversion of reactants and production of syngas, the synthesized Co-Mo-MgO/MWCNTs were found to be a suitable catalyst for the CRM reaction. The CH4 and CO2 conversions were greatly influenced by the reaction temperature in the range of 750-1000 °C. The catalyst exhibited high activity and stability during 10 h reaction time with 82.68% conversion of CH4 at 950 °C respectively, without significant deactivation. The reaction rate of CH4 and CO2 over carbon nanotubes was affected significantly by the reaction temperature. The syngas ratio was close to unity and no carbon deposition over the catalyst was observed after the termination of the reaction. © (2013) Trans Tech Publications, Switzerland.

DOI 10.4028/www.scientific.net/MSF.756.182
Citations Scopus - 2
Co-authors Mehrnoush Khavarian
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Dr Mehrnoush Khavarian

Position

Casual Research Assistant
School of Architecture and Built Environment
Faculty of Engineering and Built Environment

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