Preparation Of Nanofluids Research Articles

Study on the preparation of magnetic Janus nanofluids and oil displacement mechanism

Magnetic nanomaterials, known for their eco-friendliness, low toxicity, strong magnetic response, and reusability, have seen significant advancements in enhancing oil recovery. In this study, the surfactant and magnetic Janus nanoparticles (MJNP) were evaluated and optimized through Fourier transform infrared spectroscopy, ζ potential test, scanning electron microscope, emulsion performance evaluation and other analysis, so as to develop magnetic Janus nanofluids (MJNF). Study the flow behavior and enhanced oil recovery mechanism of this nanofluid in porous media through nuclear magnetic resonance (NMR) and numerical simulation methods. The results showed that when the concentration of surfactant (LAD-30) was 0.08%, the maximum water content of emulsion was 80%, and the viscosity increased by more than 90000%. In addition, when the MJNP concentration is 400 ppm or higher, a stable emulsion is formed at 90 °C. NMR experiment shows that through MJNF oil displacement, the oil recovery of small and medium-sized pores is significantly improved by 25.9% and 18.3%, which indicates that high viscosity emulsion can be formed in situ after MJNF injection, thus achieving consistency control. In addition, the numerical simulation results also found that MJNF injection can improve the oil-water saturation in the pore volume and enhance oil phase flow. The research results provide a new understanding for EOR of emulsion flooding.

Preparation of SiO2 solvent-free nanofluids for modification of commercial corrosion-resistant coatings

Preparation of SiO2 solvent-free nanofluids for modification of commercial corrosion-resistant coatings

Eco-friendly Synthesis of Copper Nanoparticles: An Overview of the Epoch-making Role of Natural Resources, Applications, and Recent Developments

Abstract: Green synthesized metal nanoparticles offer a broad spectrum of applications. They also offer unmatched significance because they are eco-friendly, cost-effective, and less toxic to human beings. Copper nanoparticles, when synthesized using green protocols, exhibit enriched properties and are substantially used in the preparation of nanofluids, medicine, conductive agents, etc. In this review, we have highlighted how the side effects of synthetic compounds have paved the way to look for greener alternatives in the field of nanomedicine. Green fabrication, characterization, and activities of copper nanoparticles using different biological sources have been extensively studied and reported. The biological sources have been broadly classified into two categories, plant-based and microbial-based. Natural resources are a reservoir of flavonoids, polyphenols, saponins, etc. They act as reducing and stabilizing agents for nanoparticles. Bio-synthesized metal nanoparticles have presented themselves as anti-microbial agents, bioreductors, cytotoxic agents, bioremediators, etc. This review has described the effective utilization of natural resources for synthesizing copper nanoparticles. It also emphasizes the recent developments in this field covering the diverse applications of the same.

Tribological performance of ZrO2 nanoparticles as friction and wear reduction additives in aviation lubricant

Abstract High-performance aircraft engines require superior aviation oils to enhance their lubricating performance and prolong service life. Addition of nano-sized ceramic particles has been considered as a useful way to improve the tribological performance of base fluids. Up to now, few previous studies focused on the tribological properties of ZrO2 nanoparticles in aviation oil. The current study dispersed ZrO2 nanoparticles into PAO20 aviation base oil as lubricant additives. A dual-step method comprised of physical blending and ultrasonic dispersing was applied in the preparation of ZrO2 nanofluids. Oleic acid was utilized as surfactant to enhance the stability of ZrO2 nanofluids. Ball-on-plate reciprocating sliding wear tests were conducted to obtain the coefficient of friction and wear volumes. It was found that the PAO20 base oil produced the highest coefficient of friction of 0.278 and wear volumes of 2.305╳10-2 mm3. 5wt% ZrO2 nanofluids with 5wt% oleic acid showed the best lubricating performance. The coefficient of friction was reduced by 31.29%, and wear volume was reduced by 42.95%. In the examination of wear tracks, a physically embedded tribo-layer of ZrO2 nanoparticles and an oleic acid tribo-film with low shearing resistance were formed, which lowered the friction, and protected the mating surfaces against abrasive and adhesive wear. The results obtained in this study have applicable values in the development of high-performance aviation lubricants.

Efficient nanofluids based on Ag nanoparticles and a linear silicone-based fluid for concentrating solar power

Improving the efficiency of renewable energy sources can lead to obtaining electrical energy in an environmentally-friendly way. Therefore, the development of nanofluids for use in parabolic trough collectors in concentrated solar energy (CSP-PTC) is a research line of interest. Thus, in this work, nanofluids based on Ag nanoparticles and a polydimethylsiloxane (PDMS) type fluid used in CSP-PTC technology were prepared. The use of this fluid in this technology and the preparation of nanofluids based on it has not been studied widely, and the evaluation of the use of nanofluids from this type fluid is of great interest. Thus, the physical stability and the properties of interest measured, that are density, surface tension, viscosity, isobaric specific heat and thermal conductivity, were characterized. The nanofluids prepared presented interesting thermal properties. An increase of up to 4.5 % in the isobaric specific heat and up to 24 % in thermal conductivity were observed with respect to the base fluid, without a significant increase in viscosity. Thus, an increase in the heat transfer coefficient of up to 16 % was obtained. These results are really promising for the use of the nanofluids prepared in CSP-PTC technology. Finally, the moderate increase in isobaric specific heat and the significant increase in thermal conductivity is explained by the weak Van der Waals force interaction observed between the Ag surfaces and the PDMS molecules.

Experimental Study on Preparation and Physical Properties of Nanofluids

Experimental Study on Preparation and Physical Properties of Nanofluids

Correction: Magnetic nanofluids preparation and its thermal applications: a recent review

Correction: Magnetic nanofluids preparation and its thermal applications: a recent review

Theoretical and Experimental Study on the Preparation of High-Viscosity Magnetic Nanofluid by Combined Surfactants.

In this study, the mechanism by which combined surfactants affect the dispersion stability of magnetic nanofluids (MNFs) was improved. Two stable lubricating oil-based magnetic nanofluids with high viscosity and one with low viscosity were prepared by chemical coprecipitation. Erucic acid and octanoic acid were used as the combined surfactants to modify the Fe3O4 nanoparticles (MNPs). The size and morphology of the particles were observed using TEM. The rheological properties were tested with a rotational rheometer. The magnetization of the lubricating oil-based magnetic nanofluids was characterized by VSM. The results indicated that the prepared magnetic nanofluids had high viscosity, high magnetism, and good stability. This study provided ideas for the preparation of a high-viscosity magnetic nanofluid. By using combined surfactants, sufficient steric repulsion energy can be provided to counteract the attraction energy of sterically protected nanoparticles, thus achieving a balance of the dispersion stability of MNF.

Magnetic nanofluids preparation and its thermal applications: a recent review

Magnetic nanofluids preparation and its thermal applications: a recent review

A sustainable approach for the preparation and stability of mono and hybrid nanofluids in the milling of Nickel based superalloy

This work is focused on enhancing the sustainability and machinability in finish end-milling of Nimonic 90 superalloy using nanofluid-assisted machining. The research deals with the preparation and analysis of the stability of hybrid nanofluids for the machining of Nimonic 90. The UV–visible absorption of prepared mono and hybrid nanofluids are examined and based on the absorption curves, and 1% of the weight of the nanoparticles is chosen. The samples have been used to estimate the ideal ultrasonication time and its behaviour with various ionic and non-ionic surfactants have been determined. By examining the UV–visible absorption curves, the shelf life of the hybrid nanofluid is obtained, and it is found to be equivalent to that of the freshly prepared nanofluid. When preparing nanofluids based on alumina and hBN, tween 80 and Sodium Dodecyl Sulfate (SDS) has proved to be to be superior surfactants, respectively. Furthermore, toxicity test has revealed that the well-dispersed nanofluid are non-toxic in nature, with hybrid nanofluid exhibiting 84% cell viability. The hybrid nanofluid possesses a zeta potential of −30.8 mV. Additionally, has been observed that all the prepared nanofluids exhibited Newtonian behaviour and that their viscosities are 15%–20% higher than those of the base fluid. During the nanofluid assisted machining with hybrid nanofluid, the machining results of Nimonic 90 superalloy demonstrate the synergistic influence of both nanoparticles. Compared to dry machining, the hybrid nanofluid has a 48.80% reduction in cutting forces, 72.66% reduction in cutting temperature, 63.63% reduction in surface roughness, and 46.03% reduction in flank wear. Additionally, a Pugh matrix assessment score of 9 compared to the score of −5 for dry machining indicates that the usage of hybrid nanofluid as a cutting condition has substantial potential for future sustainable machining methods.

Amplifying thermal performance of solar flat plate collector by Al2O3/ Cu/MWCNT/SiO2 mono and hybrid nanofluid

Flat plate collectors (FPCs) have garnered widespread usage in applications such as water heating, space heating, and various thermal systems, presenting an eco-friendly and sustainable approach to harnessing solar energy. However, the thermal performance of FPCs has been adversely affected by the improper selection of Heat Transfer Fluids (HTFs). The purpose of the work is to explore and demonstrate the potential advancements in solar flat plate collector (FPC) technology through the use of nanofluids to Enhance Energy Conversion, Explore Synergistic Effects, Contribute to Sustainable Energy Solutions and Address Technological Challenges. That is to optimize the thermal performance of FPCs by incorporating standalone and hybrid nanoparticles into the base fluid to augment their thermal properties. This approach explores new possibilities for synergistic effects and enhanced thermal properties, offering a novel contribution to the field of nanofluid research. The standalone and hybrid nanofluids encompass nanoparticles such as Al2O3, Cu, multi-walled carbon nanotubes (MWCNT), and SiO2 at a concentration of 0.5 wt%. In the preparation of hybrid nanofluids, equal volume fractions (25 % each) of Al2O3, Cu, MWCNT, and SiO2 nanoparticles were employed. The investigation includes the evaluation of thermal performance parameters, namely heat gain, heat loss coefficients, and thermal efficiency of FPCs, comparing these values with those of water. Hybrid nanofluids exhibit significantly improved thermal performance compared to both plain water and monodisperse nanofluids. Employing hybrid nanofluids yields results that indicate a peak outlet temperature of approximately 83.2 °C, a higher heat gains of 2385 W, a reduced heat loss coefficient of 25.5 W/m2K, and a peak thermal efficiency of 70.4 %. The use of hybrid nanofluids, as opposed to monodisperse nanofluids, offers superior thermal performance for flat plate collector-based solar heating systems.

Investigation on the synergistic effect and thermal properties of poly-hydroxyethyl methacrylate encapsulated graphene quantum dot-paraffin hybrid nanofluid

In this study, a novel water-based hybrid nanofluid was developed using poly-hydroxyethyl methacrylate-encased graphene quantum dot-paraffin nanocomposite (HEMA GQD-P). Graphene quantum dots (GQD) with an average size of 10 to 15 nm were synthesized by citric acid nucleation and the HEMA GQD-P nanocomposites were synthesized by an emulsion polymerization reaction. The emission spectra of GQD obtained using photo-luminescent spectroscopy confirm the occurrence of quantum confinement effect. The synthesis of HEMA GQD-P was carefully carried out to ensure its optimal properties. The synergistic effect due to high thermal conductivity of GQD and high latent heat capacity of paraffin were recognized in the enhanced properties of nanocomposite and hybrid nanofluid. The latent heat capacity of the synthesized nanocomposite was found to be 21.8 % higher than the pure paraffin. The prepared hybrid nanofluid possesses high dispersion stability at pH 7 and the thermal conductivity of the hybrid nanofluid enhances with an increase in nanoparticle concentration. A maximum thermal conductivity enhancement of 53 % (±2) was obtained for the hybrid nanofluid (0.3 vol%) at 30 °C. The present work reveals that the encapsulation of GQD-paraffin in a poly-hydroxyethyl methacrylate shell creates nanocomposites with high heat transfer properties. The synergistic effect of the HEMA GQD-P enhances their potential in the preparation of hybrid nanofluids with enhanced properties for desired thermal management applications.

Optimizing the thermophysical behavior of a novel ternary hybrid nanofluid for energy applications through experimental research

The continual use of fossil fuel technologies has negatively impacted on the environment and has caused huge health challenges globally. Despite the growth of renewable energy technologies, their efficiency issues have hindered widespread adoption. The use of nanofluids as heat transfer fluids in renewable energy technologies have further improved their overall efficiency, resulting in a more environmentally friendly performance of these systems. For automotive fuel and coolant systems, hybrid nanofluids are gaining appeal due to their remarkable ability to enhance thermal performance and accelerate heat transfer rates. Ternary-hybrid nanofluids, which combines three different types of nanoparticles in a wide range of mixing ratios, are an intriguing but mostly speculative concept. Optimizing the mixing ratio for effective heat transfer characteristics is important for energy applications. A unique Al2O3/ZnO/Fe3O4 ternary nanofluid is synthesized and its density is measured in this investigation. The nanofluid preparation included three different mixing ratios (1:1:1, 2:1:1, and 1:2:1), with the volume fraction between 0.5 % and 1.25 %. This study also includes a discussion of the density prediction analysis. The result shows that at a temperature of 25 °C and a volume fraction of 1.25 %, the maximum density is determined to be 1165 kg/m3. The Random Forest algorithm gives the best prediction accuracy with an R2 value of 0.928.

Darcy–Brinkman model for Boussinesq–Stokes suspension tetra dusty nanofluid flow over stretching/shrinking sheet with suction/injection

This study examines the Darcy–Brinkman model for 2-D magnetohydrodynamic fluid flow across porous stretching/shrinking surfaces. We consider water as a traditional base fluid in which the Al2O3, Silver (Ag), Titanium dioxide (TiO2 ), and Gold (Au) nanoparticles are submerged in preparation of a tetra-dusty nanofluid. The novelty of the present problem is to examine the influence of Boussinesq-Stokes suspension tetra dusty nanofluid flow with the Darcy–Brinkman model. The governing nonlinear partial differential equations are transferred to a set of ordinary differential equations through suitable similarity conversions. The methodology, the governing equations of fluid and dusty phases is transformed into nonlinear ODEs using similarity transformations. The findings demonstrate that the tetra nanofluid phase heat and mass transpiration performance is greater compared to the dusty phase. Developing tetra dusty nanofluid has significantly upsurged the heat transmission for manufacturing with numerous applications in engineering, biological, and physical sciences.

Heat Transfer Application of Nanofluids and Testing of Thermal Conductivity

In response to the growing demand for more efficient heat transfer technologies in various industrial processes, the development of nanofluids has emerged as a promising solution. Traditional heat transfer fluids like mineral oil, ethylene glycol, and water have relatively low thermal conductivities compared to solids, limiting the compactness and efficiency of heat exchangers. Nanofluids, which are created by suspending ultrafine metallic or nonmetallic solid powders in base fluids, exhibit enhanced thermal properties due to the superior thermal conductivities of solid materials. This paper reviews the preparation, thermal conductivity measurement, and influencing factors of nanofluids, with a focus on thermal conductivity as the primary driver for improved heat transfer. The preparation of nanofluids involves either a one-step or two-step method, with the two-step method being more commonly used for oxide nanoparticles (NPs) such as Al2O3, ZnO, MgO, TiO2, and SiO2. The study discusses stabilization techniques like ultrasonication and magnetic force agitation to ensure homogeneous suspension and long-term stability of the nanofluids. The thermal conductivity measurements are conducted using short hot wire (SHW) and transient hot wire (THW) techniques, with considerations of the nonsteady-state nature and potential error sources. The research underscores the importance of rigorous experimental design and accurate data analysis to address the complexities and variability in thermal conductivity measurements, ultimately contributing to the advancement of nanofluid technologies for efficient heat transfer solutions.

Developing a Novel Hybrid Nanofluid Preparation Method Using the Droplet Generation Method: Predicting the Thermal Conductivity, Viscosity, and Magnetic Properties Compared to the Conventional Two-Step Method

Developing a Novel Hybrid Nanofluid Preparation Method Using the Droplet Generation Method: Predicting the Thermal Conductivity, Viscosity, and Magnetic Properties Compared to the Conventional Two-Step Method

Role of aloe vera based nanofluids for cool thermal energy storage system: A comparative study

The present experimental investigation incorporates the preparation of aloe vera gel-based phase change nanofluid (NFPCM) for a cool thermal energy storage (CTES) system. Two sets of NFPCMs were produced by adding graphene nanoplatelets (GNP) in deionized water and aloe vera gel (0.20 wt%, 0.40 wt%, and 0.60 wt%). The zeta potential analysis shows that the NFPCM with aloe vera gel is more stable even after 60 days from the preparation (−44 mV). The thermal conductivity of NFPCMs was analyzed through the transient hot wire method and the enhancement of 42 %, and 37.5 % were measured in the ice phase for NFPCMs with aloe vera gel and DI water (0.60 wt%) respectively at the heat transfer fluid temperature of −15 °C. The NFPCMs with aloe vera gel show that the addition of GNP prepended the peak melting temperature from −16 °C to −10.5 °C, which is due to the quick formation of nuclei as compared to NFPCMs with DI water. Additionally, a slight reduction in the latent heat of only 7 % was observed. The charging characteristics of NFPCMs were studied in a single spherical capsule at −8 °C. The maximum reduction in total charging time of 25 % was recorded for the aloe vera gel-based NFPCM with a maximum concentration of GNP (0.60 wt%). The green synthesis of aloe vera gel-based NFPCM exhibited noteworthy enhancements in thermophysical properties. Additionally, it was observed that the long-term stability of the NFPCM was achieved by excluding surfactants during the preparation process. The incorporation of graphene nanoplatelets (GNP) into aloe vera gel as the foundational phase change material (PCM) facilitates the partial charging of the CTES system with a reduced energy input.

Enhancing high-speed CNC milling performance of Ti6Al4V alloy through the application of ZnO-Ag hybrid nanofluids

Abstract This research investigates the performance of high-speed CNC milling operations on Ti6Al4V alloy by employing a novel ZnO-Ag hybrid nanofluid. The study involves the preparation and characterization of nanofluids with varying concentrations of nanoparticles, focusing on thermal conductivity and stability. The machining experiments encompass four critical input parameters: Minimum Quantity Lubrication (MQL) flow rate, cutting speed, nanofluid concentration, and feed rate. Performance evaluation is based on average surface roughness (Ra) and cutting temperature. Key findings include a remarkable 21.05% improvement in thermal conductivity for the ZnO-Ag-based sunflower oil at 0.2% volume concentration compared to 0.05% concentration. The prepared nanofluids exhibit good stability. Moreover, cutting speed and MQL flow rate emerge as significant contributors to Ra, accounting for 35.62% and 34.82%, respectively. Interestingly, MQL flow rate is identified as the most influential factor, surpassing even cutting speed. SEM images for tool wear reveals that the ZnO-Ag based sunflower oil reduced tool wear significantly. In conclusion, the proposed ZnO-Ag-based sunflower oil at 0.2% concentration emerges as the good option for sustainable high-speed machining of Ti6Al4V alloy, showcasing

Darcy–Brinkman Model for Ternary Dusty Nanofluid Flow across Stretching/Shrinking Surface with Suction/Injection

Understanding of dusty fluids for different Brinkman numbers in porous media is limited. This study examines the Darcy–Brinkman model for two-dimensional magneto-hydrodynamic fluid flow across permeable stretching/shrinking surfaces with heat transfer. Water was considered as a conventional base fluid in which the copper (Cu), silver (Ag), and titanium dioxide (TiO2) nanoparticles were submerged in a preparation of a ternary dusty nanofluid. The governing nonlinear partial differential equations are converted to ordinary differential equations through suitable similarity conversions. Under radiation and mass transpiration, analytical solutions for stretching sheets/shrinking sheets are obtained. Several parameters are investigated, including the magnetic field, Darcy–Brinkman model, solution domain, and inverse Darcy number. The outcomes of the present article reveal that increasing the Brinkman number and inverse Darcy number decreases the velocity of the fluid and dusty phase. Increasing the magnetic field decreases the momentum of the boundary layer. Ternary dusty nanofluids have significantly improved the heat transmission process for manufacturing with applications in engineering, and biological and physical sciences. The findings of this study demonstrate that the ternary nanofluid phase’s heat and mass transpiration performance is better than the dusty phase’s performance.

Microfluidic controllable production and morphology-independent phase-change heat transfer of boehmite nanofluids

Enhanced boiling heat transfer through nanofluids represents a significant approach to improving the cooling performance of electronic devices. However, the preparation of nanofluids poses challenges regarding production efficiency, morphology control, and structural stability. In addition, the underlying mechanism of flow boiling heat transfer enhancement of nanofluids, particularly changes in vapor behavior, remains a limited understanding. This study presents a facile and straightforward microfluidic strategy for the controllable synthesis of nanofluids toward efficient heat transfer enhancement. The microfluidic flow synthesis approach effectively enhances mixing efficiency at various flow rates, enabling continuous and high-throughput synthesis of boehmite nanofluids with different morphologies. The synthesized nanofluids exhibit long-term stability (>50 days) at room temperature. Both rod- and sphere-shaped nanofluids under equivalent concentrations can significantly improve critical heat flux (CHF) and maximum heat transfer coefficient (HTC) across various operating parameters, but with similar enhancement characteristics. Analysis of the period of bubble growth and burst, bubble size distributions, number of bubbles, and vapor phase fractions reveals that rod- and sphere-shaped nanofluids could shorten the period, enhance surface wetting, increase nucleation sites, and reduce bubble size efficiently and similarly. Furthermore, the effect of the concentration of nanofluid on phase-change heat transfer performance is systematically explored. 0.01 wt% nanofluid behaves the most remarkable enhancement, CHF and maximum HTC are improved by 24 % and 14.4 %, respectively. These findings not only shed new light on the controllable synthesis of functional nanomaterials but also provide important guidelines for the rational design of nanofluids for efficient two-phase cooling of electronic devices.