Exploring Hydrothermal Synthesis of Nanofluids and Thermal Applications

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Nanofabrication and Nanomanufacturing".

Deadline for manuscript submissions: closed (31 August 2022) | Viewed by 17886

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Guest Editor
Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
Interests: thermal sciences and heat transfer with a focus on electronics cooling; condensation; nanofluids; heat transfer devices; thermal management
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Special Issue Information

Dear Colleagues,

We invite you to submit your latest work in our Special Issue on “Exploring Hydrothermal Synthesis of Nanofluids and Thermal Applications”.

With the advances in the nanofluid science, there are ample opportunities for the adoption of nanofluids in various engineering horizons such as thermal management, lubrication, energy harvesting, energy efficiency, etc. One of the major challenges for the adoption of nanofluids is the stability of such kinds of fluids, especially at higher temperatures. Different approaches have been proposed and adopted by researchers for various applications and temperature ranges to prepare stable nanofluids. In this Special Issue, we look into the preparation of nanofluids via hydrothermal synthesis which, due to the flexibility of wide temperature ranges, is attracting a great deal of attention around the globe. Additionally, this Special Issue will invite works performed on the important applications of nanofluids in various engineering sectors to facilitate future developments.

It is vital that recent developments on the hydrothermal synthesis of nanofluids should be given due credit for future opportunities and developments.

Dr. Hafiz Muhammad Ali
Guest Editor

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Keywords

  • hydrothermal synthesis
  • nanofluids
  • nanoparticles
  • thermal applications
  • heat transfer
  • nanofluid preparation
  • stability of nanofluids

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Published Papers (9 papers)

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Research

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18 pages, 3891 KiB  
Article
Thermal and Tribological Properties Enhancement of PVE Lubricant Modified with SiO2 and TiO2 Nanoparticles Additive
by Mohd Farid Ismail, Wan Hamzah Azmi, Rizalman Mamat and Hafiz Muhammad Ali
Nanomaterials 2023, 13(1), 42; https://doi.org/10.3390/nano13010042 - 22 Dec 2022
Cited by 14 | Viewed by 2272
Abstract
The addition of nanoparticles may have a positive or negative impact on the thermal and tribological properties of base lubricant. The objective of this paper is to investigate the effect of nanoparticle dispersion in lubricant base in relation to its application in refrigeration [...] Read more.
The addition of nanoparticles may have a positive or negative impact on the thermal and tribological properties of base lubricant. The objective of this paper is to investigate the effect of nanoparticle dispersion in lubricant base in relation to its application in refrigeration system compressors. An investigation of tribological and thermal properties of nanolubricants for rolling piston rotary systems was carried out through four-ball tribology tests and thermal conductivity measurements. Nanolubricants dispersed with SiO2 and TiO2 nanoparticles were tested at various concentrations and temperatures. The changes in thermal conductivity and coefficient of friction (COF) were analyzed while wear weight loss was also calculated from wear scar size. A regression model of thermal conductivity enhancement was proposed for both types of nanoparticles. Zeta potential results show that nanolubricants have excellent stability. The thermal conductivity increases by the increment of nanoparticle concentration but decreases by temperature. The R-square for the regression model is more than 0.9952 with an average deviation not more than 0.29%. The COF for SiO2/PVE nanolubricant at 0.003 vol.% reduced 15% from the baseline. The COF for nanolubricants exceeds the result for base lubricants when the concentration is more than the threshold value. The optimum concentration of SiO2 and TiO2 nanoparticles improved the thermal and tribological properties of PVE lubricant and may offer an advantage when applied to refrigeration systems. Full article
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16 pages, 1103 KiB  
Article
Computational Analysis for Bioconvection of Microorganisms in Prandtl Nanofluid Darcy–Forchheimer Flow across an Inclined Sheet
by Jianfeng Wang, Zead Mustafa, Imran Siddique, Muhammad Ajmal, Mohammed M. M. Jaradat, Saif Ur Rehman, Bagh Ali and Hafiz Muhammad Ali
Nanomaterials 2022, 12(11), 1791; https://doi.org/10.3390/nano12111791 - 24 May 2022
Cited by 19 | Viewed by 2325
Abstract
The two-dimensional boundary layer flow of a Prandtl nanofluid was explored in the presence of an aligned magnetic field over an inclined stretching/shrinking sheet in a non-Darcy permeable medium. To transform the PDEs of the leading equations into ODEs, a coupled boundary value [...] Read more.
The two-dimensional boundary layer flow of a Prandtl nanofluid was explored in the presence of an aligned magnetic field over an inclined stretching/shrinking sheet in a non-Darcy permeable medium. To transform the PDEs of the leading equations into ODEs, a coupled boundary value problem was formed and suitable similarity functions were used. To obtain numerical answers, an efficient code for the Runge–Kutta technique with a shooting tool was constructed with a MATLAB script. This procedure is widely used for the solution of such problems as it is efficient and cost-effective with a fifth-order accuracy. The significance of immersed parameters on the velocity, temperature, concentration, and bioconvection is shown through figures. Furthermore, the physical parameters of the skin friction coefficient and the Nusselt numbers are demonstrated in tables. The declining behavior of the flow velocity against the porosity parameter Kp and the local inertia co-efficient Fr is shown, and the both parameters of the Darcy resistance and Darcy–Forchheimer resistance are responsible for slowing the fluid speed. The increasing values of the Schmidt number Sc decrease the concentration of the nano entities. Full article
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19 pages, 9134 KiB  
Article
Natural Convection Water/Glycerin–CNT Fractionalized Nanofluid Flow in a Channel with Isothermal and Ramped Conditions
by Kashif Sadiq, Imran Siddique, Jan Awrejcewicz and Maksymilian Bednarek
Nanomaterials 2022, 12(8), 1255; https://doi.org/10.3390/nano12081255 - 7 Apr 2022
Cited by 8 | Viewed by 1662
Abstract
This article investigates heat and mass transport enrichment in natural convection fractionalized nanofluid flow inside a channel with isothermal and ramped wall conditions under the effects of chemical reactions, radiation, heat absorption, and the Soret effect. To obtain the fractional model, the Caputo [...] Read more.
This article investigates heat and mass transport enrichment in natural convection fractionalized nanofluid flow inside a channel with isothermal and ramped wall conditions under the effects of chemical reactions, radiation, heat absorption, and the Soret effect. To obtain the fractional model, the Caputo time-fractional derivative definition is used, and analytical results are obtained by the Laplace transform. In two base fluids, water and glycerin, the impacts of two nanoparticles, single-wall carbon nanotubes (SWCNTs) and multiple-wall carbon nanotubes (MWCNTs), are investigated. The comparison of six distinct fluids, including water, water–SWCNT, water–MWCNT, glycerin, glycerin–SWCNT and glycerin–WMCNT, is explored graphically. Physical parameters’ effects on isothermal and ramped conditions are graphically depicted and explained in depth. For isothermal wall conditions, the variation in concentration, temperature and velocity is exponential, while for ramped wall conditions, the variation is steady. Finally, the results of skin frictions, Nusselt numbers and Sherwood numbers and for both ramped wall and isothermal wall conditions are evaluated in tabular form for various values of volume fraction. Moreover, it is observed that the temperature, velocity, Nusselt numbers and skin frictions increase by increasing the volume fraction of CNTs. Full article
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19 pages, 6818 KiB  
Article
Heat Transfer Enhancement in Parabolic through Solar Receiver: A Three-Dimensional Numerical Investigation
by Tayeb Fahim, Samir Laouedj, Aissa Abderrahmane, Sorour Alotaibi, Obai Younis and Hafiz Muhammad Ali
Nanomaterials 2022, 12(3), 419; https://doi.org/10.3390/nano12030419 - 27 Jan 2022
Cited by 25 | Viewed by 4322
Abstract
Parabolic trough collectors (PTC) are one of the most established solar concentrating systems which have been used in a wide variety of applications. Enhancing their performance is critical to establish them as a viable technology. Internal obstacles are an intriguing way for improving [...] Read more.
Parabolic trough collectors (PTC) are one of the most established solar concentrating systems which have been used in a wide variety of applications. Enhancing their performance is critical to establish them as a viable technology. Internal obstacles are an intriguing way for improving the collector’s performance. However, the usage of obstacles results in increasing pressure loss. The purpose of this research is to numerically explore the impact of introducing obstacles to the receiver tube of a parabolic trough collector on heat transmission in PTCs and its overall thermal performance. The first part analyzed the effects of geometrical parameters, orientation angle (α = 45°, 90° or 135°), and spacing of obstacles (P/D = 1, 2, or 3) on the fluid motion, heat transfer, and performance. Then, a non-uniform heat flow was applied to the absorber’s outer surface. The effects of nanoparticles type, temperature profile, and heat transfer performance of three different nanofluids (Cu/thermal oil, Al2O3/thermal oil, andTiO2/thermal oil) were studied in the second part. The simulation results show that, the friction factor increased when P/D decreases, and that the absorber tube with obstacles discs (α = 90°) and P/D = 2 achieved the best thermal performance. Additionally, increasing the concentration of solid nanoparticles in thermal oil improves heat transmission, and the Cu nanofluid has the greatest Nusselt number. Full article
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18 pages, 2843 KiB  
Article
Numerical Study on Generalized Heat and Mass in Casson Fluid with Hybrid Nanostructures
by Muhammad A. Sadiq and Haitham M. S. Bahaidarah
Nanomaterials 2021, 11(10), 2675; https://doi.org/10.3390/nano11102675 - 11 Oct 2021
Cited by 4 | Viewed by 1598
Abstract
The rheological model for yield stress exhibiting fluid and the basic laws for fluid flow and transport of heat and mass are used for the formulation of problems associated with the enhancement of heat and mass due to dispersion of nanoparticles in Casson. [...] Read more.
The rheological model for yield stress exhibiting fluid and the basic laws for fluid flow and transport of heat and mass are used for the formulation of problems associated with the enhancement of heat and mass due to dispersion of nanoparticles in Casson. The heat and mass transfer obey non-Fourier’s laws and the generalized Fick’s law, respectively. Model problems are incorporated by thermal relaxation times for heat and mass. Transfer of heat energy and relaxation time are inversely proportional, and the same is the case for mass transport and concentration relaxation time. A porous medium force is responsible for controlling the momentum thickness. The yield stress parameter and diffusion of momentum in Casson fluid are noticed to be inversely proportional with each other. The concentration gradient enhances the energy transfer, and temperature gradient causes an enhancement diffusion of solute in Casson fluid. FEM provides convergent solutions. The relaxation time phenomenon is responsible for the restoration of thermal and solutal changes. Due to that, the thermal and solutal equilibrium states can be restored. The phenomenon of yield stress is responsible for controlling the momentum boundary layer thickness. A porous medium exerts a retarding force on the flow, and therefore, a deceleration in flow is observed. The thermal efficiency of MoS2SiO2Casson fluid is greater than the thermal efficiency of SiO2Casson fluid. Full article
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27 pages, 11236 KiB  
Article
Pool Boiling Amelioration by Aqueous Dispersion of Silica Nanoparticles
by Sayantan Mukherjee, Naser Ali, Nawaf F. Aljuwayhel, Purna C. Mishra, Swarnendu Sen and Paritosh Chaudhuri
Nanomaterials 2021, 11(8), 2138; https://doi.org/10.3390/nano11082138 - 22 Aug 2021
Cited by 11 | Viewed by 2698
Abstract
Non-metallic oxide nanofluids have recently attracted interest in pool boiling heat transfer (PBHT) studies. Research work on carbon and silica-based nanofluids is now being reported frequently by scholars. The majority of these research studies showed improvement in PBHT performance. The present study reports [...] Read more.
Non-metallic oxide nanofluids have recently attracted interest in pool boiling heat transfer (PBHT) studies. Research work on carbon and silica-based nanofluids is now being reported frequently by scholars. The majority of these research studies showed improvement in PBHT performance. The present study reports an investigation on the PBHT characteristics and performance of water-based silica nanofluids in the nucleate boiling region. Sonication-aided stable silica nanofluids with 0.0001, 0.001, 0.01, and 0.1 particle concentrations were prepared. The stability of nanofluids was detected and confirmed via visible light absorbance and zeta potential analyses. The PBHT performance of nanofluids was examined in a customized boiling pool with a flat heating surface. The boiling characteristics, pool boiling heat transfer coefficient (PBHTC), and critical heat flux (CHF) were analyzed. The effects of surface wettability, contact angle, and surface roughness on heat transfer performance were investigated. Bubble diameter and bubble departure frequency were estimated using experimental results. PBHTC and CHF of water have shown an increase due to the nanoparticle inclusion, where they have reached a maximum improvement of ≈1.33 times over that of the base fluid. The surface wettability of nanofluids was also enhanced due to a decrease in boiling surface contact angle from 74.1° to 48.5°. The roughness of the boiling surface was reduced up to 1.5 times compared to the base fluid, which was due to the nanoparticle deposition on the boiling surface. Such deposition reduces the active nucleation sites and increases the thermal resistance between the boiling surface and bulk fluid layer. The presence of the dispersed nanoparticles caused a lower bubble departure frequency by 2.17% and an increase in bubble diameter by 4.48%, which vigorously affects the pool boiling performance. Full article
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15 pages, 2916 KiB  
Article
Solution Processed Zn1−xySmxCuyO Nanorod Arrays for Dye Sensitized Solar Cells
by Muhammad Saleem, Ali Algahtani, Saif Ur Rehman, Muhammad Sufyan Javed, Kashif Irshad, Hafiz Muhammad Ali, Muhammad Zeeshan Malik, Amjad Ali, Vineet Tirth and Saiful Islam
Nanomaterials 2021, 11(7), 1710; https://doi.org/10.3390/nano11071710 - 29 Jun 2021
Cited by 20 | Viewed by 2568
Abstract
Cu- and Sm-doped ZnO nanorod arrays were grown with 1 wt% of Sm and different weight percents (0.0, 0.5, 1.0 and 1.5 wt%) of Cu by two-step hydrothermal method. The influence of Cu concentration and precursor of Sm on the structural, optical and [...] Read more.
Cu- and Sm-doped ZnO nanorod arrays were grown with 1 wt% of Sm and different weight percents (0.0, 0.5, 1.0 and 1.5 wt%) of Cu by two-step hydrothermal method. The influence of Cu concentration and precursor of Sm on the structural, optical and photovoltaic properties of ZnO nanorod arrays was investigated. An X-ray diffraction study showed that the nanorod arrays grown along the (002) plane, i.e., c-axis, had hexagonal wurtzite crystal structure. The lattice strain is present in all samples and shows an increasing trend with Cu/Sm concentration. Field emission scanning electron microscopy was used to investigate the morphology and the nanorod arrays grown vertically on the FTO substrates. The diameter of nanorod arrays ranged from 68 nm to 137 nm and was found highly dependent on Cu concentration and Sm precursor while the density of nanorod arrays almost remains the same. The grown nanorod arrays served as photoelectrodes for fabricating dye-sensitized solar cells (DSSCs). The overall light to electricity conversion efficiency ranged from 1.74% (sample S1, doped with 1 wt% of Sm and 0.0 wt% of Cu) to more than 4.14% (sample S4, doped with 1 wt% of Sm and 1.5 wt% of Cu), which is 60% higher than former sample S1. The increment in DSSCs efficiency is attributed either because of the doping of Sm3+ ions which increase the absorption region of light spectrum by up/down conversion or the doping of Cu ions which decrease the recombination and backward transfer of photo-generated electrons and increase the electron transport mobility. This work indicates that the coupled use of Cu and Sm in ZnO nanorod array films have the potential to enhance the performance of dye-sensitized solar cells. Full article
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14 pages, 3332 KiB  
Article
Characteristics and Photovoltaic Applications of Au-Doped ZnO–Sm Nanoparticle Films
by Muhammad Saleem, Kashif Irshad, Saif Ur Rehman, M. Sufyan Javed, Mohd Abul Hasan, Hafiz Muhammad Ali, Amjad Ali, Muhammad Zeeshan Malik and Saiful Islam
Nanomaterials 2021, 11(3), 702; https://doi.org/10.3390/nano11030702 - 11 Mar 2021
Cited by 23 | Viewed by 3367
Abstract
Au-doped ZnO–samarium nitrate (Sm) nanoparticles with fixed concentrations of Sm (1 wt %) and various concentrations of Au (0.0, 0.5, 1.0 and 1.5 wt %) were prepared and used as photoelectrodes to enhance the photovoltaic efficiency of dye-sensitized solar cells (DSSCs). The cell [...] Read more.
Au-doped ZnO–samarium nitrate (Sm) nanoparticles with fixed concentrations of Sm (1 wt %) and various concentrations of Au (0.0, 0.5, 1.0 and 1.5 wt %) were prepared and used as photoelectrodes to enhance the photovoltaic efficiency of dye-sensitized solar cells (DSSCs). The cell fabricated with 1.5 wt % of Au-doped ZnO–Sm nanoparticles film achieved an optimal efficiency of 4.35%, which is about 76% higher than that of 0.0 wt % of Au-doped ZnO–Sm-based cell (2.47%). This increase might be due to the formation of a blocking layer at the ZnO–Sm/Au interface, which inhibits the recombination of electrons. This increase may also be attributed to the addition of rare-earth ions in ZnO to enhance the non-absorbable wavelength region of light via up/down-conversion of near-infrared and ultraviolet radiations to visible emission and reduce the recombination loss of electron in the cell. The efficiency of cells may be increased by the blocking layer and up/down-conversion process and thus promote the overall performance of the cells. This work indicates that Au-doped ZnO–Sm nanoparticle films have the potential to increase the performance of DSSCs. Full article
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Review

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30 pages, 6489 KiB  
Review
Comparative Overview of the Performance of Cementitious and Non-Cementitious Nanomaterials in Mortar at Normal and Elevated Temperatures
by M. Arsalan Khan, M. Khalid Imam, Kashif Irshad, Hafiz Muhammad Ali, Mohd Abul Hasan and Saiful Islam
Nanomaterials 2021, 11(4), 911; https://doi.org/10.3390/nano11040911 - 2 Apr 2021
Cited by 20 | Viewed by 4535
Abstract
Nanotechnology has emerged as a field with promising applications in building materials. Nanotechnology-based mortars are examples of such building materials that have widespread applications in the construction industry. The main nanomaterials used in mortars include nano-silica, nano-magnesium oxide, nano-alumina, nano-titanium oxide, nano-zinc oxide, [...] Read more.
Nanotechnology has emerged as a field with promising applications in building materials. Nanotechnology-based mortars are examples of such building materials that have widespread applications in the construction industry. The main nanomaterials used in mortars include nano-silica, nano-magnesium oxide, nano-alumina, nano-titanium oxide, nano-zinc oxide, nano-clay, and nano-carbon. This review paper presents a summary of the properties and effects of these nanomaterials on cement mortar in terms of its fresh-state and hard-state properties. The fresh-state properties include the setting time, consistency, and workability, while the hard-state properties include mechanical properties such as compressive, flexural, tensile strengths, as well as the elasticity modulus, in addition to durability properties such as water absorption, shrinkage strain, strength loss due to freeze–thaw cycles, and chloride penetration, among others. Different nanomaterials cause different physical and chemical alterations within the microstructures of cement mortar. Therefore, the microstructural characterization and densification of mortar are discussed in detail at varying temperatures. In general, the involvement of nanomaterials in cement mortar influences the fresh-state properties, enhances the mechanical properties, and impacts the durability properties, while reducing the porosity present in the mortar matrix. Cementitious nanomaterials can create a pathway for the easy injection of binding materials into the internal microstructures of a hydration gel to impact the hydration process at different rates, whereas their non-cementitious counterparts can act as fillers. Furthermore, the research gaps and future outlook regarding the application of nanomaterials in mortar are discussed. Full article
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