Experimental investigation of the effect of pH on the stability and thermal conductivity of metal oxide nanofluids

Document Type : Research Article

Author

Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran

Abstract

The pH level of nanofluids plays an important role in stability and thermal conductivity. However limited studies have been done in this field. In this research, the effect of pH on the stability and thermal conductivity of ZnO-EG nanofluid at concentrations of 0.05 and 0.75% volumetric fraction and MgO-W at concentrations of 0.05 and 0.5% volumetric fraction were investigated. Experimental measurements of the thermal conductivity were performed by a thermal properties analyzer device at a constant temperature of 25 °C. The results showed that the pH strongly affected the stability of nanofluids so that at the pH of the isoelectric point (IEP), complete aggregation and sedimentation were observed. The thermal conductivity of nanofluids has the lowest value at the pH of the isoelectric point, but as the pH moves away from the isoelectric point, the thermal conductivity  increases. The highest enhancement in the thermal conductivity of ZnO-EG nanofluid was 63%, which was obtained at a volume fraction of 0.75% and pH = 12. However, the highest enhancement in the thermal conductivity of MgO-W nanofluid was 49%, which was obtained at a volume fraction of 0.5% and pH = 12. Finally, using the experimental results and with the help of curve fitting, equations with good quality were presented to predict the effective thermal conductivity of metal oxide nanofluids.

Keywords

Main Subjects

References

[1]. S.U.S. Choi, Enhancing thermal conductivity of fluids with nanoparticles, in:  Proceedings of the 1995 ASME International Mechanical Engineering Congress and Exposition, New York, USA, 1995, pp. 99-105.
[2]. X.-j. Wang, D.-s. Zhu, S. yang, Investigation of pH and SDBS on enhancement of thermal conductivity in nanofluids, Chem. Phys. Lett., 470(1–3) (2009) 107-111.
[3]. D. Zhu, X. Li, N. Wang, X. Wang, J. Gao, H. Li, Dispersion behavior and thermal conductivity characteristics of Al2O3–H2O nanofluids, Current Applied Physics, 9(1) (2009) 131-139.
[4]. D.M. Sabatini, leading edge nanotechnology research developments, nova science publishers, 2007.
[5]. M. Venkataraman, The effect of colloidal stability on the heat transfer characteristics of nanosilica dispersed fluids, (2005), Electronic Theses and Dissertations. 630. https://stars.library.ucf.edu/etd/630
 [6]. K.V. Wong, M.J. Castillo, Heat Transfer Mechanisms and Clustering in Nanofluids, Advances in Mechanical Engineering,2 (2010) 795478.
[7]. X. Li, D. Zhu, X. Wang, N. Wang, J. Gao, H. Li, Thermal conductivity enhancement dependent pH and chemical surfactant for Cu-H2O nanofluids, Thermochimica Acta, 469(1-2) (2008) 98-103.
[8]. J.A. Eastman, S. Choi, S. Li, W. Yu, L. Thompson, Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles, Appl. Phys. Lett., 78(6) (2001) 718-720.
[9]. Y. Ding, H. Alias, D. Wen, R.A. Williams, Heat transfer of aqueous suspensions of carbon nanotubes (CNT nanofluids), Int. J. Heat Mass Transfer, 49(1) (2006) 240-250.
[10]. C.T. Wamkam, M.K. Opoku, H. Hong, P. Smith, Effects of p H on heat transfer nanofluids containing ZrO 2 and TiO 2 nanoparticles, Journal of Applied Physics, 109(2) (2011) 024305.
[11]. H.A. Mintsa, G. Roy, C.T. Nguyen, D. Doucet, New temperature dependent thermal conductivity data for water-based nanofluids, Int J Therm Sci, 48(2) (2009) 363-371.
[12]. S.M. Abdel-Samad, A.A. Fahmy, A.A. Massoud, A.M. Elbedwehy, Experimental investigation of TiO2-water nanofluids thermal conductivity synthesized by Sol-gel technique, Current Nanoscience, 13(6) (2017) 586-594.
[13]. S. Umar, F. Sulaiman, N. Abdullah, S.N. Mohamad, Investigation of the effect of pH adjustment on the stability of nanofluid, in:  AIP Conference Proceedings, AIP Publishing LLC, 2018, pp. 020031.
[14]. J. Ji, X. Yao, J. Gao, W. Lu, W. Wang, D. Chu, Effect of surfactants and pH values on stability of γ-Al2O3 nanofluids, Chemical Physics Letters, 781 (2021) 138996.
[15]. P.K. Kanti, P. Sharma, K. Sharma, M. Maiya, The effect of pH on stability and thermal performance of graphene oxide and copper oxide hybrid nanofluids for heat transfer applications: Application of novel machine learning technique, Journal of Energy Chemistry, 82 (2023) 359-374.
[16]. H. Zhang, S. Qing, Y. Zhai, X. Zhang, A. Zhang, The changes induced by pH in TiO2/water nanofluids: Stability, thermophysical properties and thermal performance, Powder Technol., 377 (2021) 748-759.
[17]. M.H. Esfe, S. Esfandeh, D. Toghraie, Investigation of different training function efficiency in modeling thermal conductivity of TiO2/Water nanofluid using artificial neural network, Colloids Surf. Physicochem. Eng. Aspects, 653 (2022) 129811.
[18]. A. Mehralizadeh, S.R. Shabanian, G. Bakeri, Experimental and modeling study of heat transfer enhancement of TiO2/SiO2 hybrid nanofluids on modified surfaces in pool boiling process, The European Physical Journal Plus, 135(10) (2020) 796.
[19]. H. Eshgarf, A.A. Nadooshan, A. Raisi, M. Afrand, Experimental examination of the properties of Fe3O4/water nanofluid, and an estimation of a correlation using an artificial neural network, J. Mol. Liq.,  (2023) 121150.
[20]. W. Yu, H. Xie, L. Chen, Y. Li, Investigation of thermal conductivity and viscosity of ethylene glycol based ZnO nanofluid, Thermochim. Acta, 491(1-2) (2009) 92-96.
[21]. V.S. Raykar, A.K. Singh, Thermal and rheological behavior of acetylacetone stabilized ZnO nanofluids, Thermochim. Acta, 502(1-2) (2010) 60-65.
[22]. M. Pastoriza-Gallego, L. Lugo, D. Cabaleiro, J. Legido, M. Piñeiro, Thermophysical profile of ethylene glycol-based ZnO nanofluids, The Journal of Chemical Thermodynamics, 73 (2014) 23-30.
[23]. A. Singh, Synthesis, characterization, electrical and sensing properties of ZnO nanoparticles, Adv. Powder Technol., 21(6) (2010) 609-613.
[24]. M.H. Esfe, M. Afrand, A. Karimipour, W.-M. Yan, N. Sina, An experimental study on thermal conductivity of MgO nanoparticles suspended in a binary mixture of water and ethylene glycol, Int Commun Heat Mass, 67 (2015) 173-175.
[25]. O.A. Alawi, N.A.C. Sidik, H.W. Xian, T.H. Kean, S.N. Kazi, Thermal conductivity and viscosity models of metallic oxides nanofluids, Int. J. Heat Mass Transfer, 116 (2018) 1314-1325.
[26]. J. Jeong, C. Li, Y. Kwon, J. Lee, S.H. Kim, R. Yun, Particle shape effect on the viscosity and thermal conductivity of ZnO nanofluids, International journal of refrigeration, 36(8) (2013) 2233-2241.
[27]. H. Xie, W. Yu, W. Chen, MgO nanofluids: higher thermal conductivity and lower viscosity among ethylene glycol-based nanofluids containing oxide nanoparticles, J. Exp. Nanosci. 5(5) (2010) 463-472.
[28]. G.-J. Lee, C.K. Kim, M.K. Lee, C.K. Rhee, S. Kim, C. Kim, Thermal conductivity enhancement of ZnO nanofluid using a one-step physical method, Thermochim. Acta, 542 (2012) 24-27.
[29]. H. Li, L. Wang, Y. He, Y. Hu, J. Zhu, B. Jiang, Experimental investigation of thermal conductivity and viscosity of ethylene glycol based ZnO nanofluids, Appl. Therm. Eng., 88 (2015) 363-368.
[30]. M. Anish, T. Arunkumar, B. Kanimozhi, J. Jayaprabakar, N. Beemkumar, V. Jayaprakash, Experimental exploration and theoretical certainty of thermal conductivity and viscosity of MgO-therminol 55 nanofluid, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 41(4) (2019) 451-467.
[31]. S.H. Kim, S.R. Choi, D. Kim, Thermal conductivity of metal-oxide nanofluids: particle size dependence and effect of laser irradiation, ASME Journal of Heat and Mass Transfer,129(3) (2007) 298-307.
[32]. T.-P. Teng, Y.-H. Hung, T.-C. Teng, H.-E. Mo, H.-G. Hsu, The effect of alumina/water nanofluid particle size on thermal conductivity, Appl. Therm. Eng., 30 (14-15) (2010) 2213-2218.
[33]. M.O. Fatehah, H.A. Aziz, S. Stoll, Stability of ZnO nanoparticles in solution. Influence of pH, dissolution, aggregation and disaggregation effects, Journal of Colloid Science and Biotechnology, 3(1) (2014) 75-84.
[34]. B. Wang, X. Xiong, H. Ren, Z. Huang, Preparation of MgO nanocrystals and catalytic mechanism on phenol ozonation, Rsc Advances, 7(69) (2017) 43464-43473.
[35]. T. Yousefi, E. Shojaeizadeh, F. Veysi, S. Zinadini, An experimental investigation on the effect of pH variation of MWCNT–H2O nanofluid on the efficiency of a flat-plate solar collector, Solar Energy, 86(2) (2012) 771-779.
[36]. K. Goudarzi, F. Nejati, E. Shojaeizadeh, S.A. Yousef-Abad, Experimental study on the effect of pH variation of nanofluids on the thermal efficiency of a solar collector with helical tube, Exp. Therm Fluid Sci., 60 (2015) 20-27.
[37]. E.J. Wasp, J.P. Kenny, R.L. Gandhi, Solid--liquid flow: slurry pipeline transportation.[Pumps, valves, mechanical equipment, economics], Ser. Bulk Mater. Handl.;(United States), 1(4) (1977).
[38]. S. Mukherjee, P.C. Mishra, P. Chaudhuri, Thermo-economic performance analysis of Al2O3-water nanofluids—an experimental investigation, J. Mol. Liq., 299 (2020) 112200.
[39]. S. Mukherjee, S.R. Panda, P.C. Mishra, P. Chaudhuri, Enhancing thermophysical characteristics and heat transfer potential of TiO2/water nanofluid, Int. J. Thermophys., 41(12) (2020) 1-33.
Amirkabir Journal of Mechanical Engineering
Volume 55, Issue 7
October 2023
Pages 857-874

Files

Share

How to cite

Statistics