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Publications (10 of 19) Show all publications
Saleemi, M., Nikkam, N., Muhammad, M. & Toprak, M. (2015). Aging, Thermal Cycling and Stability Studies for Nanofluids. In: Aging, Thermal Cycling and Stability Studies for Nanofluids: . Paper presented at Materials Research Society (MRS) spring meeting, April 6-10, 2015. .
Open this publication in new window or tab >>Aging, Thermal Cycling and Stability Studies for Nanofluids
2015 (English)In: Aging, Thermal Cycling and Stability Studies for Nanofluids, 2015Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Stability of nanofluids is one of the critical assessments for the efficient systems that the solid content of nanofluid should be stable and well dispersed for longer time. Production of a homogenous dispersion is real technical challenge due to strong van der Waals attraction among the nanoparticles, which preferring the formation of aggregates. Stable nanofluids can be achieved via recommended physical and chemical treatments such as addition of additives and surfactants, surface-active agents to disperse hydrophobic materials, adjusting the pH value to provide electrochemical stability.Detailed investigations were carried out to identify the stability parameters, dispersion methods, application requirements, experimental investigation to determine the stability of nanofluids. Aluminum oxide (Al2O3), titanium oxide (TiO2) and cerium oxide (CeO2) were selected for these studies. Custom designed stability measurement setup was used to record the sedimentation rate. Aging test was performed in the heat transfer coefficient (HTC) setup to determine the erosion and corrosion properties. Thermal cycling was performed up to 80 oC with maximum heating cycles of 500 times. Dynamic light scattering (DLS) used to estimate the aggregate size before and after the thermal cycling and aging test. Results from the time depended DLS measurements, sedimentation rate and aging effects presents that Al2O3 nanofluids have better performance.

Keyword
nanofluid, thermal cycling, stability, nanoparticle
National Category
Engineering and Technology Materials Engineering
Identifiers
urn:nbn:se:kth:diva-166183 (URN)
Conference
Materials Research Society (MRS) spring meeting, April 6-10, 2015
Note

QC 20150601

Available from: 2015-05-04 Created: 2015-05-04 Last updated: 2015-06-01Bibliographically approved
Saleemi, M., Vanapalli, S., Nikkam, N., Toprak, M. S. & Muhammed, M. (2015). Classical Behavior of Alumina (Al2O3) Nanofluids in Antifrogen N with Experimental Evidence. Journal of Nanomaterials, 2015, Article ID 256479.
Open this publication in new window or tab >>Classical Behavior of Alumina (Al2O3) Nanofluids in Antifrogen N with Experimental Evidence
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2015 (English)In: Journal of Nanomaterials, ISSN 1687-4110, E-ISSN 1687-4129, Vol. 2015, 256479Article in journal (Refereed) Published
Abstract [en]

A nanofluid is a suspension containing nanoparticles in conventional heat transfer fluids. This paper reports on an investigation of alumina (Al2O3) nanoparticles in Antifrogen N, also called AFN, which is a popular antifreeze coolant consisting primarily of ethylene glycol and other additives to impede corrosion. The base carrier fluid is 50% by weight of water and 50% by weight of AFN. We systematically measured the nanomaterials and heat transfer data of nanofluids for four different size particles, namely, 20, 40, 150, and 250 nm alumina particles. The pH of all the nanofluids is adjusted to have a stable dispersion. The material characterizations include SEM and DLS particle measurements. We measured thermal conductivity, viscosity, and heat transfer coefficient in developing flow of the nanofluids. We observed that these nanofluids behave as any other classical fluids in thermally developing flow and classical heat transfer correlations can be used to completely describe the characteristics of these nanofluids.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2015
Keyword
Alumina, Aluminum, Coolants, Ethylene, Ethylene glycol, Heat transfer, Heat transfer coefficients, Nanoparticles, Suspensions (fluids), Thermal conductivity, Alumina particles, Classical behavior, Experimental evidence, Heat transfer correlation, Heat transfer data, Material characterizations, Particle measurement, Thermally developing flow, Nanofluidics
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-181253 (URN)10.1155/2015/256479 (DOI)2-s2.0-84945340506 (Scopus ID)
Note

QC 20160212

Available from: 2016-02-12 Created: 2016-01-29 Last updated: 2017-11-30Bibliographically approved
Nikkam, N., Ghanbarpour, M., Khodabandeh, R. & Toprak, M. S. (2015). Experimental investigation on fabrication and base liquid effect on thermo-physical characteristics of silver nanofluids. In: Experimental investigation on fabrication and base liquid effect on thermo-physical characteristics of silver nanofluids: . Paper presented at Materials Research Society (MRS) spring meeting, San Francisco, USA, April 6-10, 2015. .
Open this publication in new window or tab >>Experimental investigation on fabrication and base liquid effect on thermo-physical characteristics of silver nanofluids
2015 (English)In: Experimental investigation on fabrication and base liquid effect on thermo-physical characteristics of silver nanofluids, 2015Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Nanofluids (NFs) are solid-liquid composites prepared by stabilizing nanostructured materials in a base liquid, such as water, ethylene glycol (EG) and engine oil. They have exhibited some potential to replace with conventional heat transfer fluids to enhance their thermal characteristics. NF has complex system and its thermo-physical properties including TC and viscosity can be influenced by several factors such as base liquid. The effect of base liquid on thermo-physical properties of NFs is not well studied. In this work this effect has been studied by comparing the TC and viscosity of a commercial silver (Ag) NFs with lab-made water and EG base Ag NFs. For this purpose, at first commercial water based Ag suspension with 1wt% Ag nanoparticles (NPs) was used. The original suspension was centrifuged and the obtained Ag NPs was re-dispersed in EG to prepare EG based Ag NF (1wt%). In order to study the effect of Ag NP concentration on thermo-physical properties, NFs with various concentrations (1, 1.5 and wt%) were fabricated from the original samples containing 1wt% Ag NP. For this end NFs with higher NP concentrations were fabricated by centrifuging and concentrating these samples in base liquids. Therefore, six NFs with different base liquids (water and EG) and various Ag NP concentrations (1, 1.5 and 2wt%) were prepared and studied. The physicochemical properties of Ag NP/NF were characterized by using various techniques and instruments including Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Electron Diffraction (ED), Dynamic Light Scattering (DLS) and Fourier Transform Infrared Spectroscopy (FT-IR). Ag NP displayed an average primary particle size of 40±5 nm from SEM micrographs. The thermo-physical properties of NFs including TC and viscosity of NFs were measured at different temperatures from 20 to 40 oC. The Newtonian behavior was observed for NFs with both water and EG base liquids. Moreover, viscosity of all NFs was increased by increase of Ag NP concentration and decreased by increase in temperature. The TC of NFs was measured and analyzed by Transient Hot Wire (THW) method at the same temperature range. The TC tests showed increase of TC with the increase of Ag NPs concentration as well as increase in temperature. As a result and compared to the water based suspensions, NFs with EG base liquid revealed higher TC enhancement and lesser viscosity increase. EG based NFs seem to be more beneficial for heat transfer applications. Among all NFs, a maximum TC enhancement of ~12.2 % was obtained for EG based NF with 2wt% Ag NP at 40 oC while maximum increase in viscosity of ~ 4 % was observed for the same NF showing the capability of utilizing this NF as heat transfer fluid. Finally and in order to compare the experimental results with the estimated data, proper predictive models/correlations were applied for NFs with both water and EG base liquids and our finding are presented in detail.

Keyword
nanofluid, thermal conductivity, silver nanoparticle, viscosity
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-166182 (URN)
Conference
Materials Research Society (MRS) spring meeting, San Francisco, USA, April 6-10, 2015
Note

QC 20150612

Available from: 2015-05-04 Created: 2015-05-04 Last updated: 2017-03-01Bibliographically approved
Nikkam, N. & Toprak, M. S. (2015). Tailoring thermo-physical properties of water/ethylene glycol based nanofluids by composite SiC/SiO2 nanoparticles. In: : . Paper presented at Materials Research Society (MRS) spring meeting, April 9, 2015. .
Open this publication in new window or tab >>Tailoring thermo-physical properties of water/ethylene glycol based nanofluids by composite SiC/SiO2 nanoparticles
2015 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Conventional fluids, such as water (W), ethylene glycol (EG) and mixture of them (W/EG), are usually used as heat transfer fluids. Their poor heat transfer rate is an obstacle for enhancing efficiency of heat exchangers. A novel type of fluids called “nanofluids” (NFs) is recognized for improving the performance of heat transfer fluids. NFs are two phase fluids where solid nanoparticles (NPs) are dispersed in base liquids, which are expected to enhance the heat transfer properties of traditional fluids by improving their thermal conductivity (TC). In the last decade, NFs have achieved considerable attention due to their enhanced thermal conductivity. Mainly two methods are used to fabricate NFs: the two-step method wherein first NPs are synthesized and then dispersed in the conventional heat transfer fluids, while in the one-step method NPs are formed directly inside the base liquid. Due to large scale availability of commercial NPs, two-step method is the most commonly used technique. However, some issues such as presence of impurities or undesired phase on commercial NPs may influence the thermo-physical properties of NFs including TC and viscosity. In fact, making commercial NPs without any impurities is almost impossible and removal of undesired phases from the commercial NPs with no negative impact on NPs composition is also difficult. Hence, to study the real contribution of NPs on thermo-physical properties of NFs we performed a systematic experimental work using commercial SiC NPs with both α- and β crystal structure and silica (SiO2) NPs as secondary phase to make SiC/SiO2 composite material. The reason for selecting SiO2 is due to our recent findings on commercial α- and β SiC NPs where analysis on NPs, particularly β phase, showed silica impurity phase. Presence of this impurity/undesired phase does not reflect the real heat transport property of SiC NPs. Thus we focused on fabrication of SiC/ SiO2 composite material with different structures including core-shell structure (presence of silica phase as shell), functionalization of SiC NPs with SiO2 phase as well as addition of different percentage of SiO2 to SiC NPs as secondary phase. The obtained composite materials were used to fabricate W/EG based NFs with 9wt% NP concentration. Physicochemical properties of NPs/NFs were characterized by using various techniques. The thermo-physical properties of NFs including TC and viscosity were measured and analyzed at 20 oC. Our findings and results obtained from physico-chemical, thermo-physical and heat transport characteristics are presented in detail.

National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-166180 (URN)
Conference
Materials Research Society (MRS) spring meeting, April 9, 2015
Note

QC 20150615

Available from: 2015-05-04 Created: 2015-05-04 Last updated: 2015-06-15Bibliographically approved
Nikkam, N., Ghanbarpour, M., Khodabandeh, R. & Toprak, M. S. (2015). The effect of particle size on thermo-physical properties of ethylene glycol based copper micro- and nanofluids. In: : . Paper presented at Materials Research Society (MRS) spring meeting,San Francisco, USA, April 7, 2015. .
Open this publication in new window or tab >>The effect of particle size on thermo-physical properties of ethylene glycol based copper micro- and nanofluids
2015 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Nanofluids (NFs), suspension of nanoparticles (NPs) in conventional fluids such as water and ethylene glycol (EG) have been found capable of providing enhanced heat transfer compared to pure heat transfer fluids. Among several factors influencing thermo-physical properties of NFs including thermal conductivity (TC) and viscosity, particle size plays an essential role. Due to limited literature data on the impact of particle size on thermo-physical properties of NFs as well as inconsistent results in the literature, there is a serious need to perform a detailed study on the influence of particle size on thermo-physical properties of NFs. For this purpose a study was carried out using copper nanoparticles (Cu NPs) and copper microparticles (Cu MPs) to investigate, experimentally and theoretically, the effect of Cu NPs and MPs on thermo-physical properties of Cu NFs and Cu microfluids (Cu MFs). A series of stable Cu NFs and MFs with various NP/MP concentration (from1 wt% to 3 wt%) were fabricated by dispersing Cu NPs and Cu MPs in EG. The use of additives/surfactants was avoided to study the real impact of Cu NP/MP. The physico-chemical properties of Cu NFs and MFs were analyzed by various techniques and instruments including Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS) and Infrared Spectroscopy (FT-IR). The thermo-physical properties (TC and viscosity) of NFs and MFs were measured at different temperatures between 20 and 40 oC. All Cu NFs and MFs showed higher TC and viscosity compared to the EG base liquid. The viscosity test results showed Newtonian behavior for NFs and MFs. Our study exhibited that NFs with Cu NPs revealed higher TC than those containing Cu MPs at the same particle concentration and temperature. For TC, Maxwell predictive equation and for viscosity of NFs/MFs, Kriger-Dougherty correlation was applied to compare the experimental results with the estimated values. Our findings on the physic-chemical, thermal and thermo-physical properties of the NFs/MFs, containing Cu NPs/MPs are presented in detail.

Keyword
nanofluid, thermal conductivity, copper nanoparticle, viscosity
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-166181 (URN)
Conference
Materials Research Society (MRS) spring meeting,San Francisco, USA, April 7, 2015
Note

QC 20150615

Available from: 2015-05-04 Created: 2015-05-04 Last updated: 2017-03-01Bibliographically approved
Nikkam, N., Saleemi, M., Bitaraf Haghighi, E., Ghanbarpour, M., Toprak, M., Khodabandeh, R., . . . Palm, B. (2013). Design and Fabrication of Efficient Nanofluids Based on SiC Nanoparticles for Heat Exchange Applications. In: : . Paper presented at European Materials Research Conference, EMRS, Strasbourg, France, May 27-31, 2013. .
Open this publication in new window or tab >>Design and Fabrication of Efficient Nanofluids Based on SiC Nanoparticles for Heat Exchange Applications
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2013 (English)Conference paper, Oral presentation only (Other academic)
Keyword
SiC, Nanofluids, Thermal conductivity, Viscosity
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-124187 (URN)
Conference
European Materials Research Conference, EMRS, Strasbourg, France, May 27-31, 2013
Note

QC 20140225

Available from: 2013-06-27 Created: 2013-06-27 Last updated: 2017-03-01Bibliographically approved
Nikkam, N., Saleemi, M., Toprak, M. & Muhammed, M. (2013). Nano-engineered SiC Heat Transfer Fluids for Effective Cooling. In: : . Paper presented at Materials Research Conference, MRS, San Francisco, USA, April 1-5, 2013. .
Open this publication in new window or tab >>Nano-engineered SiC Heat Transfer Fluids for Effective Cooling
2013 (English)Conference paper, Oral presentation only (Refereed)
Keyword
SiC, Nanofluids, Thermal conductivity, Viscosity
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-124195 (URN)
Conference
Materials Research Conference, MRS, San Francisco, USA, April 1-5, 2013
Note

NQC 20140626

Available from: 2013-06-27 Created: 2013-06-27 Last updated: 2014-06-26Bibliographically approved
Nikkam, N., Ghanbarpour, M., Saleemi, M., Toprak, M. S., Muhammed, M. & Khodabandeh, R. (2013). Thermal and rheological properties of micro- and nanofluids of copper in diethylene glycol: as heat exchange liquid. In: Nanoscale Thermoelectric Materials: Thermal and Electrical Transport, and Applications to Solid-state Cooling and Power Generation. Paper presented at 2013 MRS Spring Meeting; San Francisco, CA; United States; 1 April 2013 through 5 April 2013 (pp. 165-170). Cambridge: Cambridge Scholars Publishing.
Open this publication in new window or tab >>Thermal and rheological properties of micro- and nanofluids of copper in diethylene glycol: as heat exchange liquid
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2013 (English)In: Nanoscale Thermoelectric Materials: Thermal and Electrical Transport, and Applications to Solid-state Cooling and Power Generation, Cambridge: Cambridge Scholars Publishing, 2013, , 6 p.165-170 p.Conference paper, Published paper (Refereed)
Abstract [en]

This study reports on the fabrication of nanofluids/microfluids (NFs/MFs) with experimental and theoretical investigation of thermal conductivity (TC) and viscosity of diethylene glycol (DEO) base NFs/MFs containing copper nanoparticles (Cu NPs) and copper microparticles (Cu MPs). For this purpose, Cu NPs (20-40 nm) and Cu MPs (0.5-1.5 urn) were dispersed in DEG with particle loading between 1 wt% and 3 wt%. Ultrasonic agitation was used for dispersion and preparation of stable NFs/MFs, and thus the use of surfactants was avoided. The objectives were investigation of impact of size of Cu particle and concentration on TC and viscosity of NFs/MFs on DEG as the model base liquid. The physicochemical properties of all particles and fluids were characterized by using various techniques including Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS) techniques. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed to study particles' surfaces. NFs and MFs exhibited a higher TC than the base liquid, while NFs outperformed MFs showing a potential for their use in heat exchange applications. The TC and viscosity of NFs and MFs were presented, along with a comparison with values from predictive models. While Maxwell model was good at predicting the TC of MFs, it underestimated the TC of NFs, revealing that the model is not directly applicable to the NF systems.

Place, publisher, year, edition, pages
Cambridge: Cambridge Scholars Publishing, 2013. 6 p.
Series
Materials Research Society Symposium Proceedings, ISSN 0272-9172 ; 1543
Keyword
Copper, Nanofluid, diethylene glycol, Thermal conductivity, Viscosity
National Category
Nano Technology
Research subject
SRA - Energy
Identifiers
urn:nbn:se:kth:diva-124180 (URN)10.1557/opl.2013.675 (DOI)2-s2.0-84893372647 (Scopus ID)9781605115207 (ISBN)
Conference
2013 MRS Spring Meeting; San Francisco, CA; United States; 1 April 2013 through 5 April 2013
Projects
NanoHex
Funder
EU, FP7, Seventh Framework Programme
Note

QC 20140225

Available from: 2013-06-27 Created: 2013-06-27 Last updated: 2017-03-02Bibliographically approved
Nikkam, N. (2013). Thermal and rheological properties of micro- and nanofluids of copper: designed as heat exchange fluid. In: : . Paper presented at MRS, San Francisco, USA, April 1-5, 2013. .
Open this publication in new window or tab >>Thermal and rheological properties of micro- and nanofluids of copper: designed as heat exchange fluid
2013 (English)Conference paper, Poster (with or without abstract) (Other academic)
Keyword
Copper, Nanofluid, Thermal Conductivity, Viscosity
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-124190 (URN)
Conference
MRS, San Francisco, USA, April 1-5, 2013
Note

QC 20140225

Available from: 2013-06-27 Created: 2013-06-27 Last updated: 2014-02-25Bibliographically approved
Nikkam, N., Singh, S. P., Saleemi, M., Toprak, M. & Muhammed, M. (2012). A comparative study of rheological properties and thermal conductivity of silver nanofluids in water and ethylene glycol base fluids. In: : . Paper presented at NANOTR VIII, 8th Nanoscience and Nanotechnology Congress, Ankara, Turkey, 25-29 June 2012. .
Open this publication in new window or tab >>A comparative study of rheological properties and thermal conductivity of silver nanofluids in water and ethylene glycol base fluids
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2012 (English)Conference paper, Oral presentation only (Refereed)
Keyword
silver, Nanofluids, Thermal conductivity, Viscosity
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-124196 (URN)
Conference
NANOTR VIII, 8th Nanoscience and Nanotechnology Congress, Ankara, Turkey, 25-29 June 2012
Note

QC 20131002

Available from: 2013-06-27 Created: 2013-06-27 Last updated: 2013-10-02Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1815-1053

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