Composite Nanofluids Research Articles

Experimental Investigation of Thermo-Physical Properties of Tri-Hybrid Nanoparticles in Water-Ethylene Glycol Mixture

In recent years, research has focused on enhancing the thermo-physical properties of a single component nanofluid. Therefore, hybrid or composite nanofluids have been developed to improve heat transfer performance. The thermo-physical properties of the Al2O3-TiO2-SiO2 nanoparticles suspended in a base of water (W) and ethylene glycol (EG) at constant volume ratio of 60:40 and different volume concentrations were investigated. The experiment was conducted for the volume concentrations of 0.05, 0.1, 0.2, and 0.3% of Al2O3-TiO2-SiO2 nanofluids at different temperatures of 30, 40, 50, 60, and 70 °C. Thermal conductivity and dynamic viscosity measurements were carried out at temperatures ranging from 30 to 70 °C by using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV III Ultra Rheometer, respectively. The highest thermal conductivity for tri-hybrid nanofluids was obtained at 0.3% volume concentration, and the maximum enhancement was increased up to 9% higher than the base fluid (EG/W). Tri-hybrid nanofluids with a volume concentration of 0.05% gave the lowest effective thermal conductivity of 4.8 % at 70 °C temperature. Meanwhile, the dynamic viscosity of the tri-hybrid nanofluids was influenced by volume concentration and temperature. Furthermore, tri-hybrid nanofluids behaved as a Newtonian fluid for volume concentrations from 0.05 to 3.0%. The properties enhancement ratio (PER) estimated that the tri-hybrid nanofluids will aid in heat transfer for all samples in the present. The new correlations for thermal conductivity and dynamic viscosity of tri-hybrid nanofluids were developed with minimum deviation. As a conclusion, the combination of the enhancement in thermal conductivity and dynamic viscosity for tri-hybrid at 0.3% volume concentration was found the optimum condition with more advantage for heat transfer than other concentrations.

Heat‐transfer and hydrodynamic performance investigation of graphene‐titanium dioxide composite nanofluid in micro‐heat exchangers

AbstractNanofluids have made a breakthrough contribution toward maximizing the efficiency of heat exchangers. Consequently, graphene nanofluids have attracted significant attention, as they yield the best heat‐transfer enhancement among all nanofluids; however, graphene is highly expensive, and further studies on hybrid graphene nanofluids are required to optimize costs. Research has been performed on the performance of pure graphene nanofluids, though little has been conducted on hybrid graphene nanofluids. Therefore, we investigated the hydrodynamic and convective heat‐transfer performance of graphene‐titanium dioxide composite (GTNC) nanofluid in a micro‐heat exchanger, and compared the results with the performance of pure graphene and pure titanium dioxide nanofluids under similar conditions. Herein, we report the synthesis of GTNC using our novel green micro‐synthesis technique and the preparation of graphene, titanium dioxide, and GTNC nanofluids using a two‐step method at three concentrations (0.02~0.08 wt%) using a surfactant. Furthermore, the stability and thermo‐physical properties of nanofluids were investigated, and nanofluids were studied for their effect on the performance of a counter‐current laminar flow micro‐heat exchanger at different flow rates (Re = 750‐1460). Findings show that thermal conductivity enhancement of GTNC nanofluid and pure graphene nanofluid at the highest mass fraction (0.08%) was 25.8% and 31.6%, respectively, while the maximum enhancement of convective heat‐transfer coefficient was 64.6% and 87%, respectively. These results indicate that hybrid GTNC nanofluid showed proximate thermal performance and stability level to graphene nanofluid with 50% less graphene content, which improves the economics of the process.

Influence of Magnetic Field, Thermal Radiation and Brownian Motion on Water-Based Composite Nanofluid Flow Passing Through a Porous Medium

This paper explored the effects of a three-dimensional water composite nanofluid fluid flow between two horizontal parallel platelets in a rotating device. Different criteria contrast the flow properties of the conventional fluid (water), nanofluid cup-water, Al2O3 and composite Nanofluid. Through efficient transformations, nonlinear dimensional equations are translated into dimensional expressions. For the resolution of the dimensionless Ordinary differential equations system, a semi-analytical analytical homotopy technique is used. In order to test flow, heat, and mass transmission, a graphical analysis was performed with various variables. Relevant and Graphic view with skin friction numerical values, Nusselt local count and the Sherwood counters. The magnetic parameter has been shown to speed up. Heat transmission also improves through thermophoresis, magnetic field and thermophoresis, whilst thermophoresis, Schmidt numbers and Brownian motion help to reduce the mass transmission.

Ultrasonic assisted new Al2O3@TiO2-ZnO/DW ternary composites nanofluids for enhanced energy transportation in a closed horizontal circular flow passage

Experiments were conducted to study the turbulent heat transfer growth of single pot sonochemically assisted new Al2O3@TiO2-ZnO/DW based ternary composite nanofluids in a closed circular heat exchanger under constant heat flux boundary conditions. The two-step facile nanofluid preparation approach was used to prepare the new ternary hybrid nanofluids. The UV–Vis and FESEM analysis were performed to confirm the absorbance and uniform dispersion of all nanoparticles. Under uniform heat flux conditions, Al2O3@TiO2-ZnO/DW based ternary composite nanofluids at 0.1, 0.075, 0.05, and 0.025 wt% reveals positive growth in heat transfer coefficient (h) and Nusselt numbers (Nu) with an increase in Reynolds (Re) number from 5849 to 24,544 without using any surfactant. The maximum increase in effective thermal conductivity was recorded up to 1.14 W/m.K for Al2O3@TiO2-ZnO/DW ternary composite nanofluids with 0.1 wt% at 45 °C, which increases by 69% compared to the base fluid. The overall average and local heat transfer/Nusselt numbers were noticed to improve with an increase in wt% of all metal oxide nanoparticles and Reynolds numbers (Re) under constant heat flux conditions in the circular heat exchanger. The highest heat transfer coefficient was recorded for Al2O3@TiO2-ZnO/DW ternary composite nanofluids at 0.1 wt% up to 3200 W/m2K for the highest Reynold (Re) numbers, which increases by 79% compared to the base fluid (DW). At 0.075 wt% the heat transfer enhancement was 2272 W/m2K, similarly, at 0.05 wt% the heat transfer was 2150 W/m2K while at 0.025 wt% the enhancement was 1950 W/m2K which is more than base fluid (DW). This enhancement is credited to the composite of nanoparticles with different shapes and particle sizes. The experimental results showed that the metal oxide-based new ternary composites nanofluids enhanced the thermophysical and heat transfer properties, hence, it is a suitable choice for enhanced energy transportation.

Solar vapor generation using bubbly flow nanofluids with collaborative light-harvesting nanoparticles

Nanotechnology can produce metallic particles of nanometer sizes with unique optical and thermal properties. Utilizing the nanofluid in solar systems has distinct advantages over conventional fluids in light harvesting, thermal generation and heat transport. However, the plasmonic effect only induces strong light absorption around its nature resonance peak, which is not desirable for broadband solar absorption. Herein, we propose a composite nanofluid composed of three different kinds of particles with distinguish absorbance peaks for collaborative light absorption over the entire solar spectrum. Dynamic bubbles are further introduced into the nanofluid to promote the solar vapor generation. With light absorption spanning from ultraviolet, visible to near-infrared wavelengths, these particle-bubble couplings induce multiple scattering events, increasing photon absorption and light flux within local domain, leading to intensive heating that activates phase-change evaporation in the close proximity. The bubbly flow nanofluid exhibits the best photothermal efficiency of 91.2% than that of the other counterparts, enabling fast vapor diffusion with an upward bubble-bursting flow, and therefore achieving a decent steam generation efficiency of 40.8% under one-sun irradiation. Our findings not only suggest a new way to improve solar vapor generation in laden-particle solution, but also shed lights on the development of novel solar thermal systems.

Effect of squid fin bionic surface and magnetic nanofluids on CPU cooling performance under magnetic field

AbstractIn order to improve the low cooling efficiency of electronic component, a squid fin bionic surface and composite magnetic nanofluids were developed and applied in CPU cooling. Effects of squid fin bionic surface and composite nanofluids Fe3O4‐CNTs (FCNT)/water nanofluids on CPU cooling performance under magnetic field were systematically studied. The impacts of nanofluids mass fraction, wave frequency of squid fin bionic surface, magnetic induction intensity, and Reynolds number on the flow and heat exchange characteristics of magnetic nanofluids were considered. The experimental results demonstrated that the cooling capacity of magnetic nanofluids increases with the increasing wave frequency, magnetic induction intensity, and nanofluids mass fraction. Lastly, the whole experimental system was evaluated by a comprehensive performance index, and it was found that the comprehensive performance is better with higher wave frequency and stronger magnetic field.

Natural convection of composite nanofluids based on a two-phase lattice Boltzmann model

A two-phase lattice Boltzmann method (LBM) is used to study the natural convection heat exchange characteristics of Al2O3–H2O nanofluids and (Al2O3/Cu)–H2O composite nanofluids in a rectangular cavity in this paper. It can be found that the two-phase LBM is suitable for the study on natural convection heat exchange characteristics of nanofluids, and its correctness is verified. Firstly, the effects of temperature differences (∆T = 1 K and ∆T = 11 K), nanofluids volume fractions (φ = 0.01, 0.03 and 0.05) and kinds of fluid (water, Al2O3–H2O nanofluids and Al2O3/Cu–H2O nanofluids) on the free convection are researched. Then, temperature and streamline distributions of Al2O3/Cu–H2O nanofluids are investigated, respectively. Lastly, local Nusselt number and average Nusselt number distributions of different nanofluids along with Y direction are investigated. It can be found that Al2O3/Cu–H2O nanofluids show a larger enhancement than Al2O3–H2O nanofluids and water. Al2O3/Cu–H2O and Al2O3–H2O nanofluids can strengthen the heat transfer performance by 9.9% and 5% at the extreme compared with deionized water, respectively. Besides, the maximum enhancement ratio of Al2O3/Cu–H2O and Al2O3–H2O nanofluids is 9.8% and 4.5% at small temperature difference (ΔT = 1 K), respectively, which is greater than that (1.6% and 0.36%) at big temperature difference (ΔT = 11 K).

One-pot sonochemical synthesis route for the synthesis of ZnO@TiO2/DW hybrid/composite nanofluid for enhancement of heat transfer in a square heat exchanger

The thermophysical properties of ZnO@TiO2/DW composite nanofluids with (0.1, 0.075, 0.05 and 0.025)mass% concentrations have been experimentally studied. The equal and homogenous dispersion of both ZnO and TiO2 nanoparticles with 50:50 ratio each in distilled water (DW) was attained by the sonochemical method. The efforts are directed to examine the effective thermal conductivity of the different mass% concentrations of ZnO@TiO2/DW composite nanofluid for a selected range of temperatures at 20 to 45 °C. The maximum improvement in thermal conductivity for ZnO@TiO2/DW composite nanofluid was noticed for 0.1 mass% concentration, and the maximum enhancement was spotted 47% higher than the base fluid (DW). The heat transfer properties of ZnO@TiO2/DW composite nanofluids with (0.1, 0.075, 0.05 and 0.025) mass% concentrations and base fluid (DW) in a square heat exchanger were also investigated. Average and local heat transfer values and growth in Nusselt values were conquered for different velocities and corresponding to specific Reynolds numbers range from 4550 to 20,360. The maximum improvement increases about 57% in average heat transfer (h) and Nusselt numbers correspondingly, while local heat transfer for 0.1 mass% is about 500 to 1750 W m−2 K, for 0.075 mass% is 500 to 1500 W m−2 K, for 0.05 mass% is 500 to 1370 and for 0.025 mass% is 500 to 1150 of the composite nanofluid which is greater than base fluid (DW). The ZnO and TiO2 mixture gives the best combination to enhance the overall heat transfer coefficient (h).

Thermal instability in a horizontal composite nano-liquid layer

The instability in a composite nanofluid layer has been examined when the layer is heated from below. Two different types of suspended nano-particles are considered in the same base fluid. The study is performed within the scheme of linear stability approach and the normal mode procedure is applied to investigate stability criterion. The critical value of the Rayleigh number for the commencement of instability is achieved numerically and the effect of a range of physical variables on the stability criterion is studied. We also derive the conditions for the non-occurrence of over-stability. The most stable case is found when both types of nano-particles are in the same proportion.

Experimental investigation of convective heat transfer growth on ZnO@TiO2/DW binary composites/hybrid nanofluids in a circular heat exchanger

The thermophysical properties of freely suspended ZnO and TiO2 nanoparticles in a base fluid (DW) with different mass% concentrations of ZnO@TiO2/DW binary composite nanofluids (0.1, 0.075, 0.05 and 0.025 mass%) are deliberated. ZnO have been synthesized by using a facile single-pot sonochemical method and mixed with TiO2 under high probe sonication to prepare binary composite nanofluid. The experiment of effective thermal conductivity was executed in the temperature range of 20–45 °C. The positive improvement in thermal conductivity value for ZnO@TiO2/DW binary composite nanofluids was recorded for 0.1 mass%, and the highest improvement was measured up to 36%, greater than the base fluids (DW). The convective heat transfer properties of the ZnO@TiO2/DW binary composite nanofluids with different concentrations and base fluid (DW) were also examined by using complete experimental test rig with a circular heat exchanger based on a constant heat flux boundary conditions. All the concentrations were examined to check the local and average improvement in heat transfer with Reynolds range from 5849 to 24,544. The increase in nanoparticles mass% in base fluid causes to raise the heat transfer coefficient (h) which is due to the composite nanoparticles. Finally, the maximum 600–1950 W m−2 K−1 enhancement was found in convective heat transfer with an increase in 0.1 mass% of composite nanoparticles, which is 69% greater than base fluid, while all other concentrations also shows positive enhancement as compared to base fluid (600–1870, 600–1700 and 600–1500) W m−2 K−1 correspondingly.

Electrical Conductivity Measurement of Transparent Conductive Films Based on Carbon Nanoparticles

Transparent conductive films are fundamental materials, currently used in several fields. Recently, due to their unique multifunctional properties, composite materials have started to be used in place of fluorine tin oxide and indium tin oxide in transparent conductive electrodes. However, the production of composite materials is still complicated and involves toxic chemicals. Through a simple and environmentally-friendly method, we synthesized new composite materials—conductive, transparent, and flexible films—that can be applied to the production of modern optoelectronic devices. An even dispersion of the nanoparticles was achieved by ultrasound excitation. Moreover, a series of morphological and structural investigations were conducted on the films by scanning and transmission electron microscopy, electrical conductivity, Raman spectroscopy, X-ray diffraction and testing their sheet resistance. The results indicated that the tested composite materials were ideal for film coating. The nanofluids containing multi-walled carbon nanotubes presented the highest electrical conductivity; nevertheless, all the composite nanofluids tended to have relatively high electrical conductivities. The flexible films with composite structures presented lower sheet resistances than those with single structures. Finally, the hybrid materials showed a higher transmittance.

Enhancement of photothermal conversion performance using nanofluids based on bimetallic Ag-Au alloys in nitrogen-doped graphitic polyhedrons

The working fluids with higher solar thermal conversion performance within broadband spectrum ranges are of great concern for direct absorption solar collectors (DASCs). Both metal nanoparticles with localized surface plasmon resonance (LSPR) effects and carbon nanomaterials have unique spectral absorption behaviors and have shown better photothermal performance in DASCs. In this paper, we attempted to prepare composite nanofluids including plasmonic bimetallic alloy and carbon nanomaterials to realize enhanced solar absorption and photothermal conversion performance. By taking ZIF-8-derived nitrogen-doped graphitic polyhedrons (ZNGs) as carrier, plasmonic bimetallic Ag-Au alloy nanoparticles were loaded on them by an impregnation-reduction method successfully. Ag-Au/ZNGs ethylene glycol nanofluids showed significant broadband absorption in the visible and near-infrared spectrum range at a lower concentration. Comparing to ethylene glycol, the photothermal conversion effeiency of all ZNGs nanofluids increased remarkablely. Plasmonic bimetallic Ag-Au alloy nanoparticles further improved the photothermal conversion efficiency, which was up to 74.35% for Ag-Au ZNGs nanofluids compared with 72.41%, 70.35% for Au/ZNGs, Ag/ZNGs respectively. This work presents a new way to enhance solar energy absorption and improve solar thermal conversion efficiency of nanofluids for DASCs.

Analysis of water-based composite MHD fluid flow using HAM

ABSTRACT In this study, heat and mass transfer of three-dimensional water-based composite MHD nanofluid flow through two horizontal parallel plates in a rotating system is scrutinised. Flow features of conventional fluid (water), water-based nanofluids containing CuO and Al2O3 as nanoparticles, and composite nanofluid are compared. Mathematical modelling of the problem results in a system of differential equations, which is solved using HAM. The physics of the problem is enlightened by discussing the effects of Reynolds number, Schmidt number, Radiation parameter, Magnetic parameter, Thermophoretic parameter, Brownian parameter, Permeability parameter, Rotation parameter and Prandtl number on heat and mass transfer. The maximum magnitude of the velocity is 0.14.

Protective coating of paper works: ZnO/cellulose nanocrystal composites and analytical characterization

Abstract Coating of ZnO-cellulose composites on paper surface has potential technological applications. With this motivation, a simple approach of synthesizing ZnO nanoparticles in cellulose nanocrystals (CNC) by in-situ solution casting is reported in this work. The surface morphology of ZnO nanoparticles combined with cellulose fibers and the distribution of these ZnO-cellulose composites on the paper surface were characterized by scanning electron microscopy. The results showed that ZnO nanoparticles are easily and uniformly dispersed in the CNC. The ZnO-cellulose composite nanofluids were prepared by dispersing the composites in isopropanol as a base fluid. To determine the protective potential of these coatings, the chemical and mechanical properties of coated papers after dry heat and UV accelerated aging were measured. Also, a good color stability of the paper coated by the nanocomposites was observed through colorimetric measurements. The paper coated with ZnO-cellulose composites was found to possess antibacterial and antifungal activity against five common fungi (Aspergillus niger, Aspergillus Versicolor, Rhizopus nigricans, Saccharomycetes, Mucor) observed in the archive or museum and two bacteria (Staphylococcus aureus and Escherichia coli) in common life.

Highly thermoconductive fluid with aqueous compatible graphene

Heat transfer of nanofluids is a complex phenomenon, where many factors like viscosity, surface charge, composition, and fluid stability of the dispersed nanoplatelets will affect the final thermal performance. Various layered nanoplatelets have been applied to fabricate composite nanofluids for applications on thermal management systems. Up to date, heat transfer fluids with high thermal and electrical properties have not yet been synthesized. In this study, functionalized graphene nanoplatelets (FGNs) with 1-5 atomic-thick were synthesized via a green steam exfoliated technique. Such the FGNs can generate the highly stable aqueous suspensions with high shelf life. The FGNs-water nanofluid exhibits an unprecedented thermal conductivity of 2.52 W mK−1 at 20 vol% loading of nanoplatelets, suggesting it has superb potential application on various thermal fields.

Research and development on composite nanofluids as next-generation heat transfer medium

Nanocomposite is a nanotechnology-based multiphase, high-performance composite material having combination of properties, which has been emerged as one of the promising research and development activities. Recently, nanocomposites have shown significant application opportunities for several sectors of biotechnology, engineering, and medical sciences, and its dispersed fluids (composite nanofluids) have gained huge interest and demand in wide area of engineering applications, particularly for heat transfer intensification. The main aim of the present review is to summarize the recent advances in nanocomposite-dispersed nanofluids. The synthesized methods, characterization, and applications of nanocomposites as well as the preparation, stability analysis, thermophysical, optical and electrical properties, heat transfer and pressure drop characteristics and applications of nanocomposite-dispersed nanofluids are well-grouped and discussed. Present review reveals that the nanocomposite with proper combination of nanomaterials yields superior performance characteristics compared to the individual alone for application in nanofluids, although many related aspects are still unexplored. Hence, the challenges and opportunities for future research are also identified, which will be useful for the newcomers and manufacturers in this field.

Investigation on stability of tri-hybrid nanofluids in water-ethylene glycol mixture

Nanofluid is a suspension of liquid containing metal or non-metallic nanoparticles of typical size (1-100 nm) dispersed into the base liquid. Hybrid or composite nanofluids is considered an extension of research work for single nanofluids, which can be carried out through a combination of two or more different nanoparticles - either in mixed or dispersed composites in liquids. The objective of this study is to investigate the stability of tri-hybrid nanofluids suspended in Water-Ethylene Glycol (EG) mixture. The tri-hybrid nanofluids were prepared at a volume concentration of 0.05 to 0.3% using the two-step method. Three types of nanoparticles used namely Al2O3, TiO2 and SiO2, and dispersed in a base fluid of water/EG. The investigation on the stability of the hybrid nanofluids in the present study is conducted through UV-Vis, zeta-potential, sedimentation and micrograph observation. The findings from the investigations on the visual stability of sedimentation show that the differences in concentration (0.05, 0.1, 0.2, 0.3%) have been low in day 14. It was found that 10 h sonication time is the most suitable period for sonication to obtain a stable suspension. Comparison of data concentration ratio to sedimentation for single, hybrid and tri-hybrid nanofluids presents tri-hybrid nanofluids remains stable with a concentration ratio of 80%. Zeta potential evaluation conducted for the tri-hybrid nanofluids obtained the value of 25.1 mV in the classification of good stability. It can be concluded that the tri-hybrid nanofluids were successfully prepared and achieved good stability.

Preparation of ZnO-MWCNTS nanocomposite: structural features and applications for enhanced oil recovery

Since last few decades, the importance of tertiary oil recovery is increasing day by day. Quest for novel hydrophobic materials compatible to oil for enhanced recovery using electromagnetic is the major focus in this field. In the present study, we present ZnO-MWCNT nanocomposite prepared using sol-gel technique for the application of enhanced oil recovery. XRD analysis shows that average particle size in the range of 30-39 nm. Morphology analysis showed that ZnO are coated on the surface of the MWCNT. Vibrational analysis indicated that ZnO-MWCNT nanocomposite exhibited E2 (high) mode of ZnO and G (sp2 carbon) bands of MWCNTs and intense sharp peak of Zn-O stretching bond. A 11.11% of oil recovery was observed using ZnO-MWCNT composite nanofluid. This recovery further enhanced to 16.10% under the effect of electromagnetic field. Therefore, this novel material can be used to enhance oil recovery with application of EM waves. [Received: September 7, 2017; Accepted: March 28, 2018]

Enhanced mechanical and thermal performances of epoxy resin by oriented solvent-free graphene/carbon nanotube/Fe3O4 composite nanofluid

In this work, we report a simple strategy for improving the mechanical and thermal performances of epoxy resin using a novel magnetic composite nanofluid as filler. The magnetic nanofluid, composed of multicomponent core of graphene oxide (GO)/carbon nanotube (MWCNTs)/Fe3O4 (GMF) and shell of polyether, is fabricated via a combination of ultrasonic assisted chemical coprecipitation process and post-modification. Subsequently, epoxy/GMF composite is prepared under magnetic field, in which the GMF nanoparticles are well dispersed in the epoxy resin matrix without obviously agglomeration and exhibit a directional arrangement along magnetic field. i.e., the GO sheets are induced to align parallel to the magnetic field direction, and the MWCNTs are uniformly dispersed on graphene sheets with the orientation along magnetic field, Fe3O4 nanoparticles are further encapsulated on GO/MWCNTs composites to form GMF core. The orientation degree of GMF is enhanced with an increase in the magnetic field strength. The results indicate that the Tg of composite material increases by 17 °C with increasing of GMF content. Moreover, the impact and bending performances of epoxy resin are apparently enhanced by 136.5% and 30.9% with the 1.5 wt% of oriented GMF nanofluid at 0.6 T. In addition, the epoxy/GMF composite exhibits an anisotropy in the thermal conductivity.

Up to date review on the synthesis and thermophysical properties of hybrid nanofluids

Abstract Research studies about nanofluids are on the rise owing to the mounting interest and demand for nanofluids as heat transfer fluids in a wide variety of applications in the recent years. This can be noticed from the number of papers published and in particular by journal special issues. To establish the field further, the purpose of this paper is threefold. First, it offers a literature review on hybrid or composite nanofluids, which are prepared either by dispersing different nanoparticles as individual constituents or by dispersing nanocomposite particles in the base fluid, taking 160 papers published from before 1995 to 2017 into account. Second, it offers a contemporary investigation on preparation and thermophysical properties of hybrid nanofluids. Lastly, this review outlines the applications and challenges associated with hybrid nanofluid; which should stimulate further research. This review also discusses several factors affecting the thermophysical properties; including types of nanoparticles, solid volume fraction, different base fluid, stability, temperature, particle size, shape, pH, sonication, and surfactants. There are many contradictory results found in the literature on the influence of effective parameters on thermophysical properties. It has been observed that the thermophysical properties are affected by the mentioned parameters. This review also reveals that proper characterization of hybrid nanofluids results in more efficient heat transfer fluids compared to single nanoparticle based nanofluid. However, more intense research is needed towards the selection of proper hybrid nanoparticles, their preparation, characterization and long-term stability to exploit their full potential as well as to overcome the barriers in applying these new fluids in industrial scale applications. Both practitioners in companies and academics might find this review useful, as it outlines significant lines of research in the field.