Hybrid Magnetic Nanoparticles Research Articles

Chalcone derived bis-organosilane and its magnetic nanoparticles: Unveiling precision in selective Cu(II) ion detection and elucidating biocompatibility

The escalating concern regarding the adverse effects of metal ion toxicity on both human health and environmental ecosystems necessitates the development of efficient detection methodologies. This study presents a focused investigation on the selective and sensitive detection of Cu(II) ions employing hybrid magnetic nanoparticles derived from chalcone-based bis-organosilane. These nanoparticles exhibit a notably low detection limit in the nano-scale range, rendering the sensor highly sensitive to Copper(II) ion detection while maintaining robust anti-interference capabilities, even in the presence of diverse metal ions. Real sample analysis confirms the sensor’s efficacy in detecting Cu(II) ions below WHO-prescribed levels. Computational analyses reveal molecular interactions and biological activities, including potent antibacterial and antioxidant properties, suggesting promising applications. Furthermore, the biological effectiveness of chalcone-derived bis-organosilane is investigated, unveiling notable antibacterial efficacy and also exhibiting potential as a scavenger of free radicals, indicating promising applications in both antibacterial and antioxidant domains.

A statistical model on heat transportation of hybrid magnetic nanoparticles with slip constraints on a heated shrinking sensor device using analysis of variance: Sensitivity analysis

A statistical model finds application across various engineering and scientific contexts, aiding in the analysis and enhancement of heat transfer processes. Its utility extends to supporting scientists and engineers in gaining deeper insights into the impact of diverse factors on heat transfer and optimizing procedures for enhanced efficiency. Notably, the heat transfer efficiency of hybrid nanofluids containing ferromagnetic nanoparticles outperforms that of conventional fluids. In this study, a statistical model is utilized to predict the increased heat transfer rate in a heated shrinking sensor employing hybrid magnetic nanoparticles with slip restrictions. Incorporating radiative heat flux and heat source/sink components contributes novelty to the study. The model is converted into a non-dimensional form using appropriate similarity rules, and the resulting problem is solved computationally using bvp5c, a built-in function in MATLAB. Using advanced mathematical modeling and simulations, this research evaluates system performance in various scenarios and identifies optimal conditions for maximizing heat transfer rates. The study's main outcomes are; that including the thermal radiation and Prandtl number enhances the heat transfer rate, whereas the heat source decreases it. Further, the increased modified Hartmann number and suction parameter raise the shear rate coefficient.

Numerical investigation and thermal transport features of magnetic hybrid nanoparticles flow over a poignant tiny needle subject to Joule heating and slip boundary conditions

The primary purpose of this study is to provide more information on the stable and incompressible stream of a hybrid nanofluid over a poignant tiny needle in two dimensions under slip boundary conditions. In the hybrid nanofluid flow, Al2O3 and Fe3O4 are nanoparticles, water and ethylene glycol (50:50) are considered as the base fluids. Furthermore, the impacts of Joule heating and inclined magnetic fields are considered. The PDE’s governing equations are converted into ODEs by using similarity transformations and solved by a numerical technique based on Runge–Kutta fourth-order method. The results illustrate that the crucial parameters such as the magnetic parameter, Eckert number, nanoparticles of solid volume fractions, inclined angle parameter, and Prandtl numbers significantly affect the momentum and thermal profiles. The heat transfer rate and skin friction factors are used to calculate the numerical values of various parameters, which are displayed in a table. These analyses manifest that raising the magnetic parameter results in a decrease in the hybrid nanofluid velocity under slip and no-slip circumstances. The Nusselt number has also grown as a result of the volumetric fractions of nanoparticles and the intensification of the angle parameter. This analysis might include areas such as microfluidics, biomedical devices, heat exchangers, and other engineering applications where precise control over fluid behavior and temperature distribution is important.

Heating Capacity and Biocompatibility of Hybrid Nanoparticles for Magnetic Hyperthermia Treatment.

Cancer is one of the deadliest diseases worldwide and has been responsible for millions of deaths. However, developing a satisfactory smart multifunctional material combining different strategies to kill cancer cells poses a challenge. This work aims at filling this gap by developing a composite material for cancer treatment through hyperthermia and drug release. With this purpose, magnetic nanoparticles were coated with a polymer matrix consisting of poly (L-co-D,L lactic acid-co-trimethylene carbonate) and a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer. High-resolution transmission electron microscopy and selected area electron diffraction confirmed magnetite to be the only iron oxide in the sample. Cytotoxicity and heat release assays on the hybrid nanoparticles were performed here for the first time. The heat induction results indicate that these new magnetic hybrid nanoparticles are capable of increasing the temperature by more than 5 °C, the minimal temperature rise required for being effectively used in hyperthermia treatments. The biocompatibility assays conducted under different concentrations, in the presence and in the absence of an external alternating current magnetic field, did not reveal any cytotoxicity. Therefore, the overall results indicate that the investigated hybrid nanoparticles have a great potential to be used as carrier systems for cancer treatment by hyperthermia.

Clinical symbiosis of hybrid nanoparticles and induced magnetic field on heat and mass transfer in multiple stenosed artery with erratic thrombosis

This article scrutinizes blood circulation through an artery having magnetized hybrid nanoparticles (silver and gold) with multiple stenoses at the outer walls and erratic thrombus of different radii at the center. In the realm of biomedical innovation, magnetized hybrid nanoparticles emerge as a captivating frontier. These nanoparticles, amalgamating diverse materials, exhibit magnetic properties that engender novel prospects for targeted drug delivery, medical imaging enhancement, and therapeutic interventions. The study was carried out employing modern bio-fluid dynamics (BFD) software. In this iterative procedure, a second-order finite difference approach is used to solve the governing equations with 0.005 tolerance. The experiment is performed on a blood conduit with mild stenosis assumptions, and expressions of temperature, resistance impedance to flow, velocity, wall shear stress, and pressure gradient are generated by employing related boundary conditions. No one has ever attempted to acquire the remedial impact of an induced magnetic field and hybrid nanoparticles on the bloodstream in a tapering artery containing multiple stenoses on the outside walls and multi-thrombus at the center using 3-D bio-fluid simulation. Furthermore, the study's findings are unique, and these computational discoveries were not previously published by any researcher. The findings suggest that hybrid nanoparticles can be used as medication carriers to reduce the impact of thrombosis and stenosis-induced resistance to blood flow or coagulation-related factors.

Hybrid multi-core shell magnetic nanoparticles for wet peroxide oxidation of paracetamol: Application in synthetic and real matrices

Clean water availability is becoming a matter of global concern in the last decades. The responsible entities for wastewater treatment do not have the proper facilities to deal with a wide range of pollutants. Special attention should be given to emerging contaminants, whose presence in water bodies may cause adverse effects on the aquatic ecosystem and human health. Most studies in the literature do not consider the development of their solution in real matrices, which can hinder the applicability of the explored alternative in the real scenario. Therefore, in this work, we demonstrate the applicability of hybrid magnetic nanoparticles for removing paracetamol (PCM) from simulated and real matrices by catalytic wet peroxide oxidation (CWPO). To achieve carbon coating, the nanoparticles were prepared via the traditional route (resorcinol/formaldehyde, CoFe@CRF). A new methodology was also considered for synthesizing thin-layered carbon-coated magnetic nanoparticles (phloroglucinol/glyoxalic acid, CoFe@CPG). TEM images revealed a multi-core shell structure formation, with an average carbon layer size of 7.8 ± 0.5 and 3.2 ± 0.3 nm for resorcinol/formaldehyde and phloroglucinol/glyoxalic acid methodology, respectively. Screening the materials’ activity for PCM oxidation by CWPO revealed that the nanoparticle prepared by phloroglucinol/glyoxalic acid methodology has higher performance for the degradation of PCM, achieving 63.5% mineralization after 24 h of reaction, with similar results for more complex matrices. Iron leaching measured at the end of all reactions has proven that the carbon layer protects the core against leaching.

Magnetically controlled drug delivery and hyperthermia effects of core-shell Cu@Mn3O4 nanoparticles towards cancer cells in vitro

Recent increase in the integration of nanotechnology and nanosciences to the biomedical sector fetches the human wellness through the development of sustainable treatment methodologies for cancerous tumors at all stages of their initiation and progression. This involves the development of multifunctional theranostic probes that effectively support for the early cancer diagnosis, avoiding non-target cell toxicity, controlled and customized anticancer drug release etc. Therefore, to advance the field of nanotechnology-based sustainable cancer treatment, we fabricated and tested the efficacy of anticancer drug-loaded magnetic hybrid nanoparticles (NPs) towards in vitro cell culture systems. The developed conjugate of NPs was incorporated with the functions of both controlled drug delivery and heat-releasing ability using Mn3O4 (manganese oxide) magnetic core with Cu shell encapsulated within trimethyl chitosan (TMC) biopolymer. On characterization, the Cu@Mn3O4-TMC NPs were confirmed to have an approximate size of 130 nm with full agglomeration (as observed by the HRTEM) and crystal size of 92.95 ± 18.38 nm with tetragonal hausmannite phase for Mn3O4 spinel structure (XRD). Also, the UV–Vis and FTIR analysis provided the qualitative and quantitative effects of 5-fluororacil (5-Fu) anticancer drug loading (max 68 %) onto the Cu@Mn3O4-TMC NPs. The DLS analysis indicated for the occurrence of no significant changes to the particle size (around 100 nm) of Cu@Mn3O4-TMC due to the solution dispersion thereby confirming for the aqueous stability of developed NPs. In addition, the magnetization values of Cu@Mn3O4-TMC NPs were measured to be 34 emu/g and a blocking temperature of 42 K. Further tests of magnetic hyperthermia by the Cu@Mn3O4-TMC/5-Fu NPs provided that the heat-releasing capacity (% ΔT at 15 min) increases with that of increased frequency, i.e. 28 % (440 Hz) > 22.6 % (240 Hz) > 18 % (44 Hz), and the highest specific power loss (SPL) value observed to be 488 W/g for water. Moreover, the 5-Fu drug release studies indicate that the release is high at a pH of 5.2 and almost all the loaded drug is getting delivered under the influence of the external magnetic field (430 Hz) due to the influence of both Brownian-rotation and Néel relaxation heat-mediated mechanism. The pharmacokinetic drug release studies have suggested for the occurrence of more than one model, i.e. First-order, Higuchi (diffusion), and Korsemeyer–Peppas (non-Fickian), in addition to hyperthermia. Finally, the in vitro cell culture systems (MCF-7 cancer and MCF-10 non-cancer) helped to differentiate the physiological changes due to the effects of hyperthermia and 5-Fu drug individually and as a combination of both. The observed differences of cell viability losses among both cell types are measured and discussed with the expression of heat shock proteins (HSPs) by the MCF-10 cells as against the MCF-7 cancer cells. We believe that the results generated in this project can be helpful for the designing of new cancer therapeutic models with nominal adverse effects on healthy normal cells and thus paving a way for the treatment of cancer and other deadly diseases in a sustainable manner.

Preparation and in Vitro Evaluation of Tamoxifen-Conjugated, Eco-Friendly, Agar-Based Hybrid Magnetic Nanoparticles for Their Potential Use in Breast Cancer Treatment.

Tamoxifen is the drug of choice as hormonal therapy for hormone receptor-positive breast cancers and can reduce the risk of breast cancer recurrence. However, oral tamoxifen has a low bioavailability due to liver and intestinal metabolic passes. To overcome this problem and utilize the potential of this drug to its maximum, inorganic nanoparticle carriers have been exploited and tested to increase its bioavailability. Biocompatibility and unique magnetic properties make iron oxide nanoparticles an excellent choice as a drug delivery system. In this study, we developed and tested a "green synthesis" approach to synthesize iron nanoparticles from green tea extract and coated them with agar for longer stability (AG-INPs). Later, these hybrid nanoparticles were conjugated with tamoxifen (TMX). By using this approach, we synthesized stable agar-coated tamoxifen-conjugated iron nanoparticles (TMX-AG-INPs) and characterized them with Fourier-transform infrared (FTIR) spectroscopy. The average particle size of AG-INPs was 26.8 nm, while the average particle size of tamoxifen-loaded iron nanoparticles, TMX-AG-INPs, was 32.1 nm, as measured by transmission and scanning electron microscopy. The entrapment efficiency of TMX-AG-INPs obtained by the drug release profile was 88%, with a drug loading capacity of 43.5%. TMX-AG-INPs were significantly (p < 0.001) efficient in killing breast cancer cells when tested in vitro on the established breast cancer cell line MCF-7 by cell viability assay, indicating their potential to control cell proliferation.

Numerical simulation of convection hybrid ferrofluid with magnetic dipole effect on an inclined stretching sheet

Iron oxide nanoparticles possess magnetic characteristics that enable their control and manipulation using external magnetic fields, making them suitable for a wide range of biomedical engineering applications. Consequently, this study investigates the ferrohydrodynamic interaction of hybrid magnetic nanoparticles in an ethylene glycol plus water mixture flowing over an inclined stretching sheet, taking into account the magnetic dipole effect. The governing partial differential equations are transformed into ordinary differential equations by opting the suitable similarity variables. To obtain the numerical results, an unconditionally stable implicit difference method called the Keller box method is employed. The study analyzes the effects of the inclination angle, ferrohydrodynamic interaction, ferroparticle volume fraction, and mixed convection parameter. The results indicate that an increase in the inclination angle and mixed convective parameter enhances the velocity profile and Nusselt number, whereas the ferrohydrodynamic interaction and ferroparticle volume fraction exhibit the opposite trend. Furthermore, the study reveals that under certain conditions, the presence of magnetic oxide and cobalt iron oxide suspended in an ethylene glycol plus water mixture effectively reduces the heat transfer rate.

Dynamic tuning of phase change interfacial thermal energy transport in hybrid nano-enhanced phase change materials by a non-uniform magnetic field

The present study aims to explore the synergistic enhanced phase change heat transfer behavior between magnetic field and hybrid nanoparticles under the consideration of non-Newtonian effects. The visualized experiments are conducted using thermochromic liquid crystal technology to extract the interconnection between dynamic phase change interface evolution and temperature change of hybrid nano-enhanced phase change material (HNEPCM), and thermocouples to measure temperature data inside the latent heat thermal energy storage unit. The magnetic field and hybrid nanoparticles synergistic mechanism is then further revealed based on the analysis of liquid phase fraction, Nusselt number, energy storage and energy storage efficiency. The results show that under magnetic field, the magnetic nanoparticles form a “thermal conductivity layer” at the solid-liquid interface, while the non-magnetic nanoparticles in the liquid phase region drive the phase change heat transfer to proceed. The non-Newtonian effect induced by high concentration of HNEPCM can weaken the convection intensity. The competition between natural convection and magnetic viscous effect under magnetic field is induced at different hybrid ratios of magnetic and non-magnetic nanoparticles. High hybrid ratios (R = 1.0, 1.5 and 2.0) will be more favorable to satisfy the high thermal conductivity requirement in the liquid phase region and the dynamic adjustment condition at the phase change interface. Under a non-uniform magnetic field, 1 wt.% HNEPCM with R = 1.0 is considered as the optimum strategy with better energy storage performance and higher magnetic field effect.

Hybrid Magnetic Lipid-Based Nanoparticles for Cancer Therapy.

Cancer is one of the major public health problems worldwide. Despite the advances in cancer therapy, it remains a challenge due to the low specificity of treatment and the development of multidrug resistance mechanisms. To overcome these drawbacks, several drug delivery nanosystems have been investigated, among them, magnetic nanoparticles (MNP), especially superparamagnetic iron oxide nanoparticles (SPION), which have been applied for treating cancer. MNPs have the ability to be guided to the tumor microenvironment through an external applied magnetic field. Furthermore, in the presence of an alternating magnetic field (AMF) this nanocarrier can transform electromagnetic energy in heat (above 42 °C) through Néel and Brown relaxation, which makes it applicable for hyperthermia treatment. However, the low chemical and physical stability of MNPs makes their coating necessary. Thus, lipid-based nanoparticles, especially liposomes, have been used to encapsulate MNPs to improve their stability and enable their use as a cancer treatment. This review addresses the main features that make MNPs applicable for treating cancer and the most recent research in the nanomedicine field using hybrid magnetic lipid-based nanoparticles for this purpose.

Fe3O4-SiO2 Mesoporous Core/Shell Nanoparticles for Magnetic Field-Induced Ibuprofen-Controlled Release.

Hybrid magnetic nanoparticles made up of an iron oxide, Fe3O4, core and a mesoporous SiO2 shell with high magnetization and a large surface area were proposed as an efficient drug delivery platform. The core/shell structure was synthesized by two seed-mediated growth steps combining solvothermal and sol-gel approaches and using organic molecules as a porous scaffolding template. The system presents a mean particle diameter of 30(5) nm (9 nm magnetic core diameter and 10 nm silica shell thickness) with superparamagnetic behavior, saturation magnetization of 32 emu/g, and a significant AC magnetic-field-induced heating response (SAR = 63 W/gFe3O4, measured at an amplitude of 400 Oe and a frequency of 307 kHz). Using ibuprofen as a model drug, the specific surface area (231 m2/g) of the porous structure exhibits a high molecule loading capacity (10 wt %), and controlled drug release efficiency (67%) can be achieved using the external AC magnetic field for short time periods (5 min), showing faster and higher drug desorption compared to that of similar stimulus-responsive iron oxide-based nanocarriers. In addition, it is demonstrated that the magnetic field-induced drug release shows higher efficiency compared to that of the sustained release at fixed temperatures (47 and 53% for 37 and 42 °C, respectively), considering that the maximum temperature reached during the exposure to the magnetic field is well below (31 °C). Therefore, it can be hypothesized that short periods of exposure to the oscillating field induce much greater heating within the nanoparticles than in the external solution.

Sensitive and quantitative in vivo analysis of PD-L1 using magnetic particle imaging and imaging-guided immunotherapy.

The programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1) expression correlate with the immunotherapeutic response rate. The sensitive and non-invasive imaging of immune checkpoint biomarkers is favorable for the accurate detection and characterization, image-guided immunotherapy in cancer precision medicine. Magnetic particle imaging (MPI), as a novel and emerging imaging modality, possesses the advantages of high sensitivity, no image depth limitation, positive contrast, and absence of radiation. Hence, in this study, we performed the pioneer investigation of monitoring PD-L1 expression using MPI and the MPI-guided immunotherapy. We developed anti-PD-L1 antibody (aPDL1)-conjugated magnetic fluorescent hybrid nanoparticles (MFNPs-aPDL1) and utilized MPI in combination with fluorescence imaging (FMI) to dynamically monitor and quantify PD-L1 expression in various tumors with different PD-L1 expression levels. The ex vivo real-time polymerase chain reaction (qPCR), western blotting, and immunofluorescence staining analysis were further performed to validate the in vivo imaging observation. Moreover, the MPI was further performed for the guidance of immunotherapy. Our data showed that PD-L1 expression can be specifically and sensitively monitored and quantified using MPI and FMI imaging methods, which were validated by ex vivo qPCR and western blotting analysis. In addition, MPI-guided PD-L1 immunotherapy can enhance the effectiveness of cancer immunotherapy. To our best knowledge, this is the pioneer study to utilize MPI in combination with a newly developed MFNPs-aPDL1 imaging probe to dynamically visualize and quantify PD-L1 expression in tumor microenvironment. This imaging strategy may facilitate the clinical optimization of immunotherapy management.

Smart chitosan–folate hybrid magnetic nanoparticles for targeted delivery of doxorubicin to osteosarcoma cells

Chitosan (CS)-based pH-sensitive nanocomposites were fabricated for the targeted delivery of doxorubicin (DOX) to osteosarcoma cells. To prepare the nanocomposite, CS was functionalized with succinic anhydride (SA) (CS-SA). CS-folic acid (FA) conjugates were produced by the conjugation of CS with FA via an amide bond. Next, Fe3O4 magnetic nanoparticles (MNPs) ferrofluid was fabricated, and nanocomposite was produced using MNPs and synthesized CS–SA/CS-FA and CS–SA via an inclusion formation between −COOH groups of CS-SA and hydroxyl groups of Fe3O4. Finally, DOX molecules were loaded onto the nanocomposites. The nanocomposites were characterized through FT-IR, DLS, XRD, VSM, TEM, and UV-Vis spectroscopy analyses. DOX release profile at various pHs indicated an enhanced release of DOX in acidic conditions. The cytotoxicity assay demonstrated that the nanocarriers alone were cytocompatible on cells examined. The MG-63 cells, which partly express the folate receptors (FRs), particularly FR-α, showed meaningfully higher cellular uptake of the DOX-loaded CS-FA/CS-SA@MNPs than the FR-negative lung cancer A549 cells. The DOX-loaded CS-FA/CS-SA-MNPs could induce significant cytotoxicity in the MG-63 cells but not in A549 cells. Based on these findings, the DOX-loaded CS-FA/ CS-SA-MNPs might be considered a smart pH-sensitive nanosystem for the targeted delivery of anticancer agents to osteosarcoma cancer cells.

Solid phase extraction of arsenic on modified MWCNT/Fe3O4 magnetic hybrid nanoparticles from copper ores samples with ETAAS determination

A simple procedure for the synthesis of magnetic hybrid nanoparticles (MHNP) was developed by combining multi-walled carbon nanotubes modified by microwave energy and magnetic iron oxide nanoparticles. MHNP were introduced as sorbents in a magnetic solid phase extraction methodology for the total Arsenic determination in copper ore samples. Arsenic is penalized contaminant element in copper ores. Arsenic was determined by electrothermal atomic absorption spectrometry with a reduced temperature program. Arsenic adsorption corresponded to 96 - 104%, at ug g−1 levels. After a variable screening stage using a Placket-Burman (PBD) experimental design, the developed methodology was optimized using a Box-Behnken experimental design. Based on the optimal working parameters, a detection limit of 30 ng L−1 was reached, with a relative standard deviation of 7.1% and a preconcentration factor (PF) of 50. The Certified Geochem Base Metal Reference Material Product Code GBM900-10 was analyzed for the validation stage.

Dendrimer-based magneto-plasmonic nanosorbents for water quality monitoring using surface-enhanced Raman spectroscopy

In this work, we report the synthesis of magneto-plasmonic dendrimer-based nanosorbents containing Au nanostars and we demonstrate that they can be used as versatile optical sensors for the detection of pesticides in spiked water samples. The magnetic hybrid nanoparticles were obtained by conjugating silica-functionalized G5-NH2 PAMAM dendrimers to silica-coated magnetite cores. The resulting magnetic-PAMAM conjugates were then used to reduce and sequester Au seeds for the subsequent in situ growth of Au nanostars. The dendrimer-based magneto-plasmonic substrates containing the Au anisotropic nanophases were then investigated regarding their ability to monitor water quality through surface-enhanced Raman scattering (SERS) spectroscopy. As a proof-of-concept, the ensuing multifunctional materials were investigated as SERS probing systems to detect dithiocarbamate pesticides (ziram and thiram) dissolved in water samples. It was observed that the magneto-plasmonic hybrid materials enhance the Raman signal of these pesticides under variable operational conditions, suggesting the versatility of these systems for water quality monitoring. Moreover, a detailed analysis of the SERS data was accomplished to predict the adsorption profile of the dithiocarbamate pesticides to the Au surface.

On-Demand Chemomagnetic Modulation of Striatal Neurons Facilitated by Hybrid Magnetic Nanoparticles.

Minimally invasive manipulation of cell signaling is critical in basic neuroscience research and in developing therapies for neurological disorders. Here, we describe a wireless chemomagnetic neuromodulation platform for the on-demand control of primary striatal neurons that relies on nanoscale heating events. Iron oxide magnetic nanoparticles (MNPs) are functionally coated with thermoresponsive poly (oligo (ethylene glycol) methyl ether methacrylate) (POEGMA) brushes loaded with dopamine. Dopamine loaded MNPs-POEGMA are co-cultured with primary striatal neurons. When alternating magnetinec fields (AMF) are applied, MNPs undergo hysteresis power loss and dissipate heat. The local heat produced by MNPs initiates a thermodynamic phase transition on POEGMA brushes resulting in polymer collapse and dopamine release. AMF-triggered dopamine release enhances the response of dopamine ion channels expressed on the cell membranes enhancing the activity of ~50% of striatal neurons subjected to the treatment. Chemomagnetic actuation on dopamine receptors is confirmed by blocking D1 and D2 receptors. The reversible thermodynamic phase transition of POEGMA brushes allow the on-demand release of dopamine in multiple microdoses. AMF-triggered dopamine release from MNPs-POEGMA causes no cell cytotoxicity nor promotes cell ROS production. This research represents a fundamental step forward for the chemomagnetic control of neural activity using hybrid magnetic nanomaterials with tailored physical properties.

Magnetic-hybrid nanoparticles with stretching/shrinking cylinder in a suspension of MoS4 and copper nanoparticles

The main intent of the present study is to explore the varying fluid momentum and thermal energy characteristics of the laminar, steady, incompressible, two-dimensional, non-Newtonian pseudo plastic Williamson hybrid nanofluid over a stretching cylinder with variability in thermal conduction, suction, injection, heat generation and magneto hydrodynamic effects are considered. The mixture of Cu and MoS4 as nanoparticles in water as its base fluid is taken for this investigation as an hybrid nanofluid. The formulated governing PDEs are modified by employing with appropriate dimensionless transformations to get the non-linear ordinary differential equations. In accordance with the help of Runge-Kutta method of order four, shooting technique is implemented by making use of boundary value problem solver, bvp4c, which is accessible as an in-built function in MATLAB software for the numerical solution of the problem. The finding of this study are The values of Cf of the fluid grows with an increasing values of the physical parameters such as M and γ, whereas it is negatively influenced by λ. The values Nu of the Williamson hybrid Nano fluid has an increasing effect for the ascending entries of γ as well as Pr and has a reverse effect for the values of λ, M, β and ε of the fluid flow.

Heat transfer enhancement compared to entropy generation by imposing magnetic field and hybrid nanoparticles in mixed convection of a Bingham plastic fluid in a ventilated enclosure

PurposeThe purpose of this study is to analyze the nonhomogeneous model on the mixed convection of Al2O3–Fe3O4 Bingham plastic hybrid nanofluid in a ventilated enclosure subject to an externally imposed uniform magnetic field. Entropy generation and the pressure drop are determined to analyze the performance of the heat transfer. The significance of Joule heating arising due to the applied magnetic field on the heat transfer of the yield stress fluid is described.Design/methodology/approachThe ventilation in the enclosure of heated walls is created by an opening on one vertical wall through which cold fluid is injected and another opening on the opposite vertical wall through which fluid can flow out.FindingsThis study finds that the inclusion of Fe3O4 nanoparticles with the Al2O3-viscoplastic nanofluid augments the heat transfer. This rate of enhancement in heat transfer is higher than the rate by which the entropy generation is increased as well as the enhancement in the pressure drop. The yield stress has an adverse effect on the heat transfer; however, it favors thermal mixing. The magnetic field, which is acting opposite to the direction of the inlet jet, manifests heat transfer of the viscoplastic hybrid nanofluid. The horizontal jet of cold fluid produces the optimal heat transfer.Originality/valueThe objective of this study is to analyze the impact of the inclined cold jet of viscoplastic electrically conducting hybrid nanofluid on heat transfer from the enclosure in the presence of a uniform magnetic field. The combined effect of hybrid nanoparticles and a magnetic field to enhance heat transfer of a viscoplastic fluid in a ventilated enclosure has not been addressed before.

TiO2-Modified Magnetic Nanoparticles (Fe3O4) with Antibacterial Properties

This paper presents the synthesis and characteristics of Fe3O4/C/TiO2 hybrid magnetic nanomaterials with antibacterial properties. The materials used were obtained using a microwave-assisted two-stage precipitation method. In the first stage, magnetite nanoparticles (Fe3O4) were prepared with the precipitation method, during which an additional glucose layer was placed on them. Next, the surface of Fe3O4 nanoparticles was covered by TiO2. It was observed that the addition of carbon and titanium dioxide caused a decrease in the average size of magnetite crystallites from 15.6 to 9.2 nm. Materials with varying contents of anatase phase were obtained. They were characterized in terms of phase composition, crystallite size, specific surface area, surface charge and the kinds of function groups on the surface. The results show a successful method of synthesizing hybrid magnetic nanoparticles, stable in a solution, with antibacterial properties under direct solar light irradiation. Compared to classical materials based on TiO2 and used for water disinfection, the obtained photocatalytic nanomaterials have magnetic properties. Owing to this fact, they can be easily removed from water once their activity under direct irradiance in a given process has completed.