Nanofluid

A nanofluid is a fluid containing nanometer-sized particles, called nanoparticles. These fluids are engineered colloidal suspensions of nanoparticles in a base fluid.[1][2] The nanoparticles used in nanofluids are typically made of metals, oxides, carbides, or carbon nanotubes. Common base fluids include water, ethylene glycol[3] and oil.

This article is about fluids containing nanoparticles. For the dynamics of fluids confined in nanoscale structures, see Nanofluidics.

Nanofluids have novel properties that make them potentially useful in many applications in heat transfer,[4] including microelectronics, fuel cells, pharmaceutical processes, and hybrid-powered engines,[5] engine cooling/vehicle thermal management, domestic refrigerator, chiller, heat exchanger, in grinding, machining and in boiler flue gas temperature reduction. They exhibit enhanced thermal conductivity and the convective heat transfer coefficient compared to the base fluid.[6] Knowledge of the rheological behaviour of nanofluids is found to be critical in deciding their suitability for convective heat transfer applications.[7][8] Nanofluids also have special acoustical properties and in ultrasonic fields display additional shear-wave reconversion of an incident compressional wave; the effect becomes more pronounced as concentration increases.[9]

In analysis such as computational fluid dynamics (CFD), nanofluids can be assumed to be single phase fluids;[10] however, almost all new academic papers use a two-phase assumption. Classical theory of single phase fluids can be applied, where physical properties of nanofluid is taken as a function of properties of both constituents and their concentrations.[11] An alternative approach simulates nanofluids using a two-component model.[12]

The spreading of a nanofluid droplet is enhanced by the solid-like ordering structure of nanoparticles assembled near the contact line by diffusion, which gives rise to a structural disjoining pressure in the vicinity of the contact line.[13] However, such enhancement is not observed for small droplets with diameter of nanometer scale, because the wetting time scale is much smaller than the diffusion time scale.[14]

Synthesis

Nanofluids are produced by several techniques:

  1. Direct Evaporation (1 step)
  2. Gas condensation/dispersion (2 step)
  3. Chemical vapour condensation (1 step)
  4. Chemical precipitation (1 step)
  5. Bio-based (2 step)

Several liquids including water, ethylene glycol, and oils have been used as base fluids. Although stabilization can be a challenge, on-going research indicates that it is possible. Nano-materials used so far in nanofluid synthesis include metallic particles, oxide particles, carbon nanotubes, graphene nano-flakes and ceramic particles.[15][16]

A bio-based, environmentally friendly approach for the covalent functionalization of multi-walled carbon nanotubes (MWCNTs) using clove buds was developed.[17][18] There are no any toxic and hazardous acids which are typically used in common carbon nanomaterial functionalization procedures, employed in this synthesis. The MWCNTs are functionalized in one pot using a free radical grafting reaction. The clove-functionalized MWCNTs are then dispersed in distilled water (DI water), producing a highly stable MWCNT aqueous suspension (MWCNTs Nanofluid).

Smart cooling nanofluids

Realizing the modest thermal conductivity enhancement in conventional nanofluids, a team of researchers at Indira Gandhi Centre for Atomic Research Centre, Kalpakkam developed a new class of magnetically polarizable nanofluids where the thermal conductivity enhancement up to 300% of basefluids is demonstrated. Fatty-acid-capped magnetite nanoparticles of different sizes (3-10 nm) have been synthesized for this purpose. It has been shown that both the thermal and rheological properties of such magnetic nanofluids are tunable by varying the magnetic field strength and orientation with respect to the direction of heat flow.[19][20][21] Such response stimuli fluids are reversibly switchable and have applications in miniature devices such as micro- and nano-electromechanical systems.[22][23] In 2013, Azizian et al. considered the effect of an external magnetic field on the convective heat transfer coefficient of water-based magnetite nanofluid experimentally under laminar flow regime. Up to 300% enhancement obtained at Re=745 and magnetic field gradient of 32.5 mT/mm. The effect of the magnetic field on the pressure drop was not as significant.[24]

Response stimuli nanofluids for sensing applications

Researchers have invented a nanofluid-based ultrasensitive optical sensor that changes its colour on exposure to extremely low concentrations of toxic cations.[25] The sensor is useful in detecting minute traces of cations in industrial and environmental samples. Existing techniques for monitoring cations levels in industrial and environmental samples are expensive, complex and time-consuming. The sensor is designed with a magnetic nanofluid that consists of nano-droplets with magnetic grains suspended in water. At a fixed magnetic field, a light source illuminates the nanofluid where the colour of the nanofluid changes depending on the cation concentration. This color change occurs within a second after exposure to cations, much faster than other existing cation sensing methods.

Such response stimulus nanofluids are also used to detect and image defects in ferromagnetic components. The photonic eye, as it has been called, is based on a magnetically polarizable nano-emulsion that changes colour when it comes into contact with a defective region in a sample. The device might be used to monitor structures such as rail tracks and pipelines.[26][27]

    Magnetically responsive photonic crystals nanofluids

    Magnetic nanoparticle clusters or magnetic nanobeads with the size 80–150 nanometers form ordered structures along the direction of the external magnetic field with a regular interparticle spacing on the order of hundreds of nanometers resulting in strong diffraction of visible light in suspension.[28][29]

    Nanolubricants

    Another word used to describe nanoparticle based suspensions is Nanolubricants.[30] They are mainly prepared using oils used for engine and machine lubrication. So far several materials including metals, oxides and allotropes of carbon have been used to formulate nanolubricants. The addition of nanomaterials mainly enhances the thermal conductivity and anti-wear property of base oils. Although MoS2, graphene, Cu based fluids have been studied extensively, the fundamental understanding of underlying mechanisms is still needed.

    Molybdenum disulfide (MoS2) and graphene work as third body lubricants, essentially becoming tiny microscopic ball bearings, which reduce the friction between two contacting surfaces.[31][32] This mechanism is beneficial if a sufficient supply of these particles are present at the contact interface. The beneficial effects are diminished as the rubbing mechanism pushes out the third body lubricants. Changing the lubricant, like-wise, will null the effects of the nanolubricants drained with the oil.

    Other nanolubricant approaches, such as Magnesium Silicate Hydroxides (MSH) rely on nanoparticle coatings by synthesizing nanomaterials with adhesive and lubricating functionalities. Research into nanolubricant coatings has been conducted in both the academic and industrial spaces.[33][34] Nanoborate additives as well as mechanical model descriptions of diamond-like carbon (DLC) coating formations have been developed by Ali Erdemir at Argonne National Labs.[35] Companies such as TriboTEX provide consumer formulations of synthesized MSH nanomaterial coatings for vehicle engines and industrial applications.[36][31]

    Nanofluids in petroleum refining process

    Many researches claim that nanoparticles can be used to enhance crude oil recovery.[37] It is evident that development of nanofluids for oil and gas industry has a great practical aspects.

    Applications

    Nanofluids are primarily used for their enhanced thermal properties as coolants in heat transfer equipment such as heat exchangers, electronic cooling system(such as flat plate) and radiators.[38] Heat transfer over flat plate has been analyzed by many researchers.[39] However, they are also useful for their controlled optical properties.[40][41][42][43] Graphene based nanofluid has been found to enhance Polymerase chain reaction[44] efficiency. Nanofluids in solar collectors is another application where nanofluids are employed for their tunable optical properties.[45][46]

    Thermophysical properties of nanofluids

    Nanoparticle migration

    The early studies indicating anomalous increases in nanofluid thermal properties over those of the base fluid, particularly the heat transfer coefficient, have been largely discredited. One of the main conclusions taken from a study involving over thirty labs throughout the world[47] was that "no anomalous enhancement of thermal conductivity was observed in the limited set of nanofluids tested in this exercise". The COST funded research programme, Nanouptake (COST Action CA15119) was founded with the intention "to develop and foster the use of nanofluids as advanced heat transfer/thermal storage materials to increase the efficiency of heat exchange and storage systems". One of the final outcomes, involving an experimental study in five different labs, concluded that "there are no anomalous or unexplainable effects".[48]

    Despite these apparently conclusive experimental investigations theoretical papers continue to follow the claim of anomalous enhancement, see,[49][50][51][52][53][54][55] particularly via Brownian and thermophoretic mechanisms, as suggested by Buongiorno.[2] Brownian diffusion is due to the random drifting of suspended nanoparticles in the base fluid which originates from collisions between the nanoparticles and liquid molecules. Thermophoresis induces nanoparticle migration from warmer to colder regions, again due to collisions with liquid molecules. The mismatch between experimental and theoretical results is explained in Myers et al.[56] In particular it is shown that Brownian motion and thermophoresis effects are too small to have any significant effect: their role is often amplified in theoretical studies due to the use of incorrect parameter values. Experimental validation of the assertions of [56] are provided in Alkasmoul et al.[57] Brownian diffusion as a cause for enhanced heat transfer is dismissed in the discussion of the use of nanofluids in solar collectors.

    See also

    [58]

    References
    1. Taylor, R.A.; et al. (2013). "Small particles, big impacts: A review of the diverse applications of nanofluids". Journal of Applied Physics. 113 (1): 011301–011301–19. Bibcode:2013JAP...113a1301T. doi:10.1063/1.4754271.
    2. Buongiorno, J. (March 2006). "Convective Transport in Nanofluids". Journal of Heat Transfer. 128 (3): 240–250. doi:10.1115/1.2150834. Retrieved 27 March 2010.
    3. "Argonne Transportation Technology R&D Center". Retrieved 27 March 2010.
    4. Minkowycz, W., et al., Nanoparticle Heat Transfer and Fluid Flow, CRC Press, Taylor & Francis, 2013
    5. Das, Sarit K.; Stephen U. S. Choi; Wenhua Yu; T. Pradeep (2007). Nanofluids: Science and Technology. Wiley-Interscience. p. 397. Archived from the original on 3 December 2010. Retrieved 27 March 2010.
    6. Kakaç, Sadik; Anchasa Pramuanjaroenkij (2009). "Review of convective heat transfer enhancement with nanofluids". International Journal of Heat and Mass Transfer. 52 (13–14): 3187–3196. doi:10.1016/j.ijheatmasstransfer.2009.02.006.
    7. S. Witharana, H. Chen, Y. Ding; Stability of nanofluids in quiescent and shear flow fields, Nanoscale Research Letters 2011, 6:231 http://www.nanoscalereslett.com/content/6/1/231/
    8. Chen, H.; Witharana, S.; et al. (2009). "Predicting thermal conductivity of liquid suspensions of nanoparticles (nanofluids) based on Rheology". Particuology. 7 (2): 151–157. doi:10.1016/j.partic.2009.01.005.
    9. Forrester, D. M.; et al. (2016). "Experimental verification of nanofluid shear-wave reconversion in ultrasonic fields". Nanoscale. 8 (10): 5497–5506. Bibcode:2016Nanos...8.5497F. doi:10.1039/C5NR07396K. PMID 26763173.
    10. Alizadeh, M. R.; Dehghan, A. A. (2014-02-01). "Conjugate Natural Convection of Nanofluids in an Enclosure with a Volumetric Heat Source". Arabian Journal for Science and Engineering. 39 (2): 1195–1207. doi:10.1007/s13369-013-0658-2. ISSN 2191-4281.
    11. Maiga, Sidi El Becaye; Palm, S.J.; Nguyen, C.T.; Roy, G; Galanis, N (3 June 2005). "Heat transfer enhancement by using nanofluids in forced convection flows". International Journal of Heat and Fluid Flow. 26 (4): 530–546. doi:10.1016/j.ijheatfluidflow.2005.02.004.
    12. Kuznetsov, A.V.; Nield, D.A. (2010). "Natural convective boundary-layer flow of a nanofluid past a vertical plate". International Journal of Thermal Sciences. 49 (2): 243–247. doi:10.1016/j.ijthermalsci.2009.07.015.
    13. Wasan, Darsh T.; Nikolov, Alex D. (May 2003). "Spreading of nanofluids on solids". Nature. 423 (6936): 156–159. Bibcode:2003Natur.423..156W. doi:10.1038/nature01591. PMID 12736681.
    14. Lu, Gui; Hu, Han; Duan, Yuanyuan; Sun, Ying (2013). "Wetting kinetics of water nano-droplet containing non-surfactant nanoparticles: A molecular dynamics study". Appl. Phys. Lett. 103 (25): 253104. Bibcode:2013ApPhL.103y3104L. doi:10.1063/1.4837717.
    15. Kumar Das, Sarit (December 2006). "Heat Transfer in Nanofluids—A Review". Heat Transfer Engineering. 27 (10): 3–19. Bibcode:2006HTrEn..27....3D. doi:10.1080/01457630600904593.
    16. Nor Azwadi, Che Sidik (2014). "A review on preparation methods and challenges of nanofluids". International Communications in Heat and Mass Transfer. 54: 115–125. doi:10.1016/j.icheatmasstransfer.2014.03.002.
    17. Sadri, R (15 October 2017). "A bio-based, facile approach for the preparation of covalently functionalized carbon nanotubes aqueous suspensions and their potential as heat transfer fluids". Journal of Colloid and Interface Science. 504: 115–123. Bibcode:2017JCIS..504..115S. doi:10.1016/j.jcis.2017.03.051. PMID 28531649.
    18. Hosseini, M (February 22, 2017). "Experimental Study on Heat Transfer and Thermo-Physical Properties of Covalently Functionalized Carbon Nanotubes Nanofluids in an Annular Heat Exchanger: A Green and Novel Synthesis". Energy & Fuels. 31 (5): 5635–5644. doi:10.1021/acs.energyfuels.6b02928.
    19. Heysiattalab, S.; Malvandi, A.; Ganji, D. D. (2016-07-01). "Anisotropic behavior of magnetic nanofluids (MNFs) at filmwise condensation over a vertical plate in presence of a uniform variable-directional magnetic field". Journal of Molecular Liquids. 219: 875–882. doi:10.1016/j.molliq.2016.04.004.
    20. Malvandi, Amir (2016-06-01). "Anisotropic behavior of magnetic nanofluids (MNFs) at film boiling over a vertical cylinder in the presence of a uniform variable-directional magnetic field". Powder Technology. 294: 307–314. doi:10.1016/j.powtec.2016.02.037.
    21. Malvandi, Amir (2016-05-15). "Film boiling of magnetic nanofluids (MNFs) over a vertical plate in presence of a uniform variable-directional magnetic field". Journal of Magnetism and Magnetic Materials. 406: 95–102. Bibcode:2016JMMM..406...95M. doi:10.1016/j.jmmm.2016.01.008.
    22. J. Philip, Shima.P.D. & B. Raj (2006). "Nanofluid with tunable thermal properties". Applied Physics Letters. 92 (4): 043108. Bibcode:2008ApPhL..92d3108P. doi:10.1063/1.2838304.
    23. Shima P.D.and J. Philip (2011). "Tuning of Thermal Conductivity and Rheology of Nanofluids using an External Stimulus". J. Phys. Chem. C. 115 (41): 20097–20104. doi:10.1021/jp204827q.
    24. Azizian, R.; Doroodchi, E.; McKrell, T.; Buongiorno, J.; Hu, L.W.; Moghtaderi, B. (2014). "Effect of magnetic field on laminar convective heat transfer of magnetite nanofluids". Int. J. Heat Mass. 68: 94–109. doi:10.1016/j.ijheatmasstransfer.2013.09.011.
    25. Mahendran, V. (2013). "Spectral Response of MagneticNanofluid to Toxic Cations". Appl. Phys. Lett. 102 (16): 163109. Bibcode:2013ApPhL.102p3109M. doi:10.1063/1.4802899.
    26. Mahendran, V. (2012). "Nanofluid based opticalsensor for rapid visual inspection of defects in ferromagnetic materials". Appl. Phys. Lett. 100 (7): 073104. Bibcode:2012ApPhL.100g3104M. doi:10.1063/1.3684969.
    27. "Nanofluid sensor images defects". nanotechweb.org. Retrieved 8 June 2015.
    28. He, Le; Wang, Mingsheng; Ge, Jianping; Yin, Yadong (18 September 2012). "Magnetic Assembly Route to Colloidal Responsive Photonic Nanostructures". Accounts of Chemical Research. 45 (9): 1431–1440. doi:10.1021/ar200276t. PMID 22578015.
    29. http://nanos-sci.com/technology.html Properties and use of magnetic nanoparticle clusters (magnetic nanobeads)
    30. Rasheed, A.K.; Khalid, M.; Javeed, A.; Rashmi, W.; Gupta, T.C.S.M.; Chan, A. (November 2016). "Heat transfer and tribological performance of graphene nanolubricant in an internal combustion engine". Tribology International. 103: 504–515. doi:10.1016/j.triboint.2016.08.007.
    31. Anis M, AlTaher G, Sarhan W, Elsemary M. Nanovate : Commercializing Disruptive Nanotechnologies.
    32. Fox-Rabinovich GS, Totten GE. Self-Organization during Friction : Advanced Surface-Engineered Materials and Systems Design. CRC/Taylor & Francis; 2007.
    33. Rudenko P (Washington SU, Chang Q, Erdemir A (Argonne NL. Effect of Magnesium Hydrosillicate on Rolling Element Bearings. In: STLE 2014 Annual Meeting. ; 2014.
    34. Chang Q, Rudenko P (Washington SU, Miller D, et al. Diamond like Nanocomposite Boundary Films from Synthetic Magnesium Silicon Hydroxide (MSH) Additives.; 2014.
    35. Erdemir A, Ramirez G, Eryilmaz OL, et al. Carbon-based tribofilms from lubricating oils. Nature. 2016;536(7614):67-71. doi:10.1038/nature18948.
    36. TriboTEX. http://tribotex.com/. Accessed September 30, 2017.
    37. Suleimanov, B.A.; Ismailov, F.S.; Veliyev, E.F. (2011-08-01). "Nanofluid for enhanced oil recovery". Journal of Petroleum Science and Engineering. 78 (2): 431–437. doi:10.1016/j.petrol.2011.06.014. ISSN 0920-4105.
    38. "Advances in Mechanical Engineering". hindawi.com. Retrieved 8 June 2015.
    39. http://nanofluid.ir Archived 2013-11-11 at the Wayback Machine
    40. Phelan, Patrick; Otanicar, Todd; Taylor, Robert; Tyagi, Himanshu (2013-05-17). "Trends and Opportunities in Direct-Absorption Solar Thermal Collectors". Journal of Thermal Science and Engineering Applications. 5 (2): 021003. doi:10.1115/1.4023930. ISSN 1948-5085.
    41. Hewakuruppu, Yasitha L.; Dombrovsky, Leonid A.; Chen, Chuyang; Timchenko, Victoria; Jiang, Xuchuan; Baek, Sung; Taylor, Robert A. (2013-08-20). "Plasmonic "pump–probe" method to study semi-transparent nanofluids". Applied Optics. 52 (24): 6041–50. Bibcode:2013ApOpt..52.6041H. doi:10.1364/ao.52.006041. PMID 24085009.
    42. Lv, Wei; Phelan, Patrick E.; Swaminathan, Rajasekaran; Otanicar, Todd P.; Taylor, Robert A. (2012-11-21). "Multifunctional Core-Shell Nanoparticle Suspensions for Efficient Absorption". Journal of Solar Energy Engineering. 135 (2): 021004. doi:10.1115/1.4007845. ISSN 0199-6231.
    43. Otanicar, Todd P.; Phelan, Patrick E.; Taylor, Robert A.; Tyagi, Himanshu (2011-03-22). "Spatially Varying Extinction Coefficient for Direct Absorption Solar Thermal Collector Optimization". Journal of Solar Energy Engineering. 133 (2): 024501. doi:10.1115/1.4003679. ISSN 0199-6231.
    44. "Enhancing the efficiency of polymerase chain reaction using graphene nanoflakes - Abstract - Nanotechnology - IOPscience". iop.org. Retrieved 8 June 2015.
    45. Taylor, Robert A (2011). "Nanofluid optical property characterization: towards efficient direct absorption solar collectors". Nanoscale Research Letters. 6 (1): 225. Bibcode:2011NRL.....6..225T. doi:10.1186/1556-276X-6-225. PMC 3211283. PMID 21711750.
    46. Taylor, Robert A (October 2012). "Nanofluid-based optical filter optimization for PV/T systems". Light: Science & Applications. 1 (10): e34. Bibcode:2012LSA.....1E..34T. doi:10.1038/lsa.2012.34.
    47. Buongiorno, Jacopo; Venerus, David C.; Prabhat, Naveen; McKrell, Thomas; Townsend, Jessica; Christianson, Rebecca; Tolmachev, Yuriy V.; Keblinski, Pawel; Hu, Lin-wen; Alvarado, Jorge L.; Bang, In Cheol (2009-11-01). "A benchmark study on the thermal conductivity of nanofluids". Journal of Applied Physics. 106 (9): 094312–094312–14. Bibcode:2009JAP...106i4312B. doi:10.1063/1.3245330. hdl:1721.1/66196. ISSN 0021-8979.
    48. Buschmann, M. H.; Azizian, R.; Kempe, T.; Juliá, J. E.; Martínez-Cuenca, R.; Sundén, B.; Wu, Z.; Seppälä, A.; Ala-Nissila, T. (2018-07-01). "Correct interpretation of nanofluid convective heat transfer". International Journal of Thermal Sciences. 129: 504–531. doi:10.1016/j.ijthermalsci.2017.11.003. ISSN 1290-0729.
    49. Bahiraei, Mehdi (2015-09-01). "Effect of particle migration on flow and heat transfer characteristics of magnetic nanoparticle suspensions". Journal of Molecular Liquids. 209: 531–538. doi:10.1016/j.molliq.2015.06.030.
    50. Malvandi, A.; Ghasemi, Amirmahdi; Ganji, D. D. (2016-11-01). "Thermal performance analysis of hydromagnetic Al2O3-water nanofluid flows inside a concentric microannulus considering nanoparticle migration and asymmetric heating". International Journal of Thermal Sciences. 109: 10–22. doi:10.1016/j.ijthermalsci.2016.05.023.
    51. Bahiraei, Mehdi (2015-05-01). "Studying nanoparticle distribution in nanofluids considering the effective factors on particle migration and determination of phenomenological constants by Eulerian–Lagrangian simulation". Advanced Powder Technology. Special issue of the 7th World Congress on Particle Technology. 26 (3): 802–810. doi:10.1016/j.apt.2015.02.005.
    52. Pakravan, Hossein Ali; Yaghoubi, Mahmood (2013-06-01). "Analysis of nanoparticles migration on natural convective heat transfer of nanofluids". International Journal of Thermal Sciences. 68: 79–93. doi:10.1016/j.ijthermalsci.2012.12.012.
    53. Malvandi, A.; Moshizi, S. A.; Ganji, D. D. (2016-01-01). "Two-component heterogeneous mixed convection of alumina/water nanofluid in microchannels with heat source/sink". Advanced Powder Technology. 27 (1): 245–254. doi:10.1016/j.apt.2015.12.009.
    54. Malvandi, A.; Ganji, D. D. (2014-10-01). "Brownian motion and thermophoresis effects on slip flow of alumina/water nanofluid inside a circular microchannel in the presence of a magnetic field". International Journal of Thermal Sciences. 84: 196–206. doi:10.1016/j.ijthermalsci.2014.05.013.
    55. Bahiraei, Mehdi; Abdi, Farshad (2016-10-15). "Development of a model for entropy generation of water-TiO2 nanofluid flow considering nanoparticle migration within a minichannel". Chemometrics and Intelligent Laboratory Systems. 157: 16–28. doi:10.1016/j.chemolab.2016.06.012.
    56. Myers, Tim G.; Ribera, Helena; Cregan, Vincent (2017-08-01). "Does mathematics contribute to the nanofluid debate?". International Journal of Heat and Mass Transfer. 111: 279–288. arXiv:1902.09346. doi:10.1016/j.ijheatmasstransfer.2017.03.118. ISSN 0017-9310.
    57. Alkasmoul, Fahad S.; Al-Asadi, M. T.; Myers, T. G.; Thompson, H. M.; Wilson, M. C. T. (2018-11-01). "A practical evaluation of the performance of Al2O3-water, TiO2-water and CuO-water nanofluids for convective cooling" (PDF). International Journal of Heat and Mass Transfer. 126: 639–651. doi:10.1016/j.ijheatmasstransfer.2018.05.072. ISSN 0017-9310.
    58. Khashi’ie, N.S., Md Arifin, N., Nazar, R., Hafidzuddin, E.H., Wahi, N. and Pop, I., 2019. A Stability Analysis for Magnetohydrodynamics Stagnation Point Flow with Zero Nanoparticles Flux Condition and Anisotropic Slip. Energies, 12(7), p.1268. https://doi.org/10.3390/en12071268.

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