Concentration Of Nanoparticles Research Articles

Influence of SS316L Nanoparticles on the Sintered Properties of Two-Component Micro-Powder Injection Moulded Bimodal SS316L/Zirconia Bi-Materials

Two-component micro-powder injection moulding (2C-μPIM) is a prospective approach for fabricating bi-material micro-components of stainless steel 316L (SS316L) and 3 mol% yttria-stabilised zirconia (3YSZ) at an appealing cost. However, the fundamental challenge lies in preventing the formation of large-scale cracks at the interface of two different materials during sintering. This study investigated how SS316L nanoparticles in bimodally configured SS316L powder that incorporated both nanoparticles and microparticles influenced the sintering of 2C-μPIM-processed miniature bi-materials made of bimodal SS316L and 3YSZ. In this study, feedstocks were developed by integrating monomodal (micro-sized) SS316L powder, three types of nano/micro-bimodal SS316L powders, and 3YSZ powder individually with palm stearin and low-density polyethylene binders. The results indicated that increasing the SS316L nanoparticle content to 45 vol.% caused a 19.5% increase in the critical powder loading in the bimodal SS316L powder as compared to that in the monomodal SS316L powder. The addition of SS316L nanoparticles increased the relative density and hardness of the sintered bi-materials, with the maximum values obtained being 96.8% and 1156.8 HV, respectively. Field emission scanning electron microscopy investigations revealed that adding 15 vol.% and 30 vol.% SS316L nanoparticle contents reduced interface cracks in bi-materials significantly, while 45 vol.% resulted in a crack-free interface.

Enhancing the Thermophysical Properties of Lubricating Oils of Refrigeration System Using CuO/CeO2 as a Mixture of Nanoparticles

The compressor is the heart of the refrigeration system, extension of its life and preservation of its moving parts such as pistons, rotors, valves, connecting rods and cranks lubrication require improvement. Recently the studies focus on the use nanoparticles with lubricants in refrigeration and air conditioning systems in view of their significant impact on improving the coefficient of performance of these systems as well as thermophysical properties of pure lubricating oils and thus reducing energy consumption. In this study, nanoparticles were synthesized in an easy and cheap way and from materials available in chemistry laboratories as following copper oxide, cerium oxide, mixture 1 consisted of 50% copper oxide with 50% cerium oxide, mixture 2 consisted of 60% copper oxide with 40% cerium oxide, mixture 3 consisted of 70% copper oxide with 30% cerium oxide, mixture 4 consisted of 40% copper oxide with 60% cerium oxide, and mixture 5 consisted of 30% copper oxide with 70% cerium oxide to study their effectiveness on enhancing the thermophysical properties of POE, PAG lubricating oil using mathematical equations available from earlier studies. The results obtained from the mathematical equations showed an increase in the viscosity of POE from 40 mm2/sec to 45 mm2/sec at 0.05 wt.% and reached 108.86 mm2/sec by increasing the concentration of nanoparticles to 0.33wt.%, as well as the improvement of viscosity of PAG from 46 mm2/sec to 52.9 mm2/sec at the concentration of nanoparticles 0.05 wt.%, recording a significant improvement when the concentration of nanoparticles reached 0.33 wt.%, as well as for the rest of the other physical properties. This is consistent with earlier studies that confirmed the improvement of the physical properties of lubricants through mixing them with nanoparticles.

Twisted-tape inserts of rectangular and triangular sections in turbulent flow of CMC/CuO non-Newtonian nanofluid into an oval tube

Purpose This paper aims to study numerically the non-Newtonian solution of carboxymethyl cellulose in water along with copper oxide nanoparticles, which flow turbulently through twisted smooth and finned tubes. Design/methodology/approach The twisted-tape inserts of rectangular and triangular sections are investigated under constant wall heat flux and the nanoparticle concentration varies between 0% and 1.5%. Computational fluid dynamics simulation is first validated by experimental information from two test cases, showing that the numerical results are in good agreement with previous studies. Here, the impact of nanoparticle concentration, tube twist and fins shape on the heat transfer and pressure loss of the system is measured. It is accomplished using longitudinal rectangular and triangular fins in a wide range of prominent parameters. Findings The results show that first, both the Nusselt number and friction factor increase with the rise in the concentration of nanoparticles and twist of the tube. Second, the trend is repeated by adding fins, but it is more intense in the triangular cases. The tube twist increases the Nusselt number up to 9%, 20% and 46% corresponding to smooth tube, rectangular and triangular fins, respectively. The most twisted tube with triangular fins and the highest value of concentration acquires the largest performance evaluation criterion at 1.3, 30% more efficient than the plain tube with 0% nanoparticle concentration. Originality/value This study explores an innovative approach to enhancing heat transfer in a non-Newtonian nanofluid flowing through an oval tube. The use of twisted-tape inserts with rectangular and triangular sections in this specific configuration represents a novel method to improve fluid flow characteristics and heat transfer efficiency. This study stands out for its originality in combining non-Newtonian fluid dynamics, nanofluid properties and geometric considerations to optimize heat transfer performance. The results of this work can be dramatically considered in advanced heat exchange applications.

Apoptotic Impact of Heliox Cold Plasma on a Cervical Cell Line Using Gold Nanoparticle-Doped Graphene Oxide Nanosheets

Background: Invasive cervical cancer is recognized as the second most common malignancy in women after breast cancer. Objectives: This study investigates, for the first time, the effect of gold nanoparticle-doped graphene oxide (GO) nanosheets on the human epithelial carcinoma (HeLa) cell line in the presence of heliox cold plasma. Methods: Graphene oxide nanosheets were synthesized using the Hummer method and then doped with gold nanoparticles. The nanoparticles were characterized by transmission electron microscopy (TEM), and the diffraction peaks of GO and gold nanoparticles were confirmed through X-ray diffraction (XRD) analysis. Additionally, the optical absorbance of the nanoparticles was measured in the range of 200 - 900 nm using UV-Visible spectroscopy. A plasma generator was fabricated to produce cold plasma using helium (He) and oxygen (O₂) gases at a 99:1 ratio. The radicals generated by the cold plasma were analyzed via optical emission spectroscopy (OES). Cell treatment was conducted by applying various concentrations of GO and GO/Au nanoparticles. Cellular phenotype was monitored through optical microscopy, and biocompatible concentrations of both nanoparticles were determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Subsequently, cold plasma at varying distances and durations was applied to the nanoparticle-treated cells. The generated radicals and the expression of apoptotic genes in treated cells were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and real-time PCR, respectively. Results: The width of the bacillus-like gold nanoparticles was 15.13 ± 0.96 nm. The cold plasma generated radicals such as N2I2⁺, N2II1⁻, He•, and O⁻•. XRD analysis confirmed the successful coupling of gold onto the GO nanosheets. The biocompatible concentrations of GO and GO/Au nanoparticles were found to be 30 µg/100 µL and 20 µg/100 µL, respectively, as determined by the MTT assay. Radical formation increased as incubation time was extended from 30 to 60 seconds. Furthermore, real-time PCR analysis demonstrated the highest levels of p53, Bax, and caspase 3/8 expression at a plasma exposure time of 60 seconds in the composite-treated group, while Bcl2 expression was significantly reduced. Conclusions: The findings suggest that the parameters of heliox cold plasma and the concentrations of GO/Au nanoparticles must be optimized to effectively induce apoptosis in cervical cancer cells.

Investigation of the efficacy of siRNA-mediated KRAS gene silencing in pancreatic cancer therapy

Aim Pancreatic carcinoma is an aggressive cancer that progresses without many symptoms. The difficulty of early diagnosis and an inadequate response to traditional treatments also cause the survival rate of pancreatic cancer to be low. Current research is focusing on methods of diagnosis and treatment, such as gene therapy, to increase survival rates. Small interfering ribonucleic acid (siRNA) has emerged as a promising advanced therapeutic strategy for cancer treatment. This study sought to silence the KRAS gene in the human pancreatic carcinoma cell line using a complex of small interfering ribonucleic acid (siRNA) and gold nanoparticles (AuNP). Methods In this study, 25 nM siRNA and gold nanoparticles at 0.5 mg/ml, 0.25 mg/ml, and 0.125 mg/ml concentrations were used to silence the KRAS gene in the CAPAN-1 cell line. Real-time PCR analysis, agarose gel electrophoresis, and double staining were carried out, and xCelligence real-time cell analysis (RTCA) was used to measure proliferation. Results The PCR analysis revealed crossing point (CP) values of actin beta (ACTB) ranging from 33.04 to 35.98, which was in the expected range for all samples. The interaction between the gold nanoparticle/siRNA complex in the double staining analysis revealed that the most effective concentration of gold nanoparticle was 0.125 mg/ml. The WST-1 technique showed that siRNA/AuPEI cells in application groups had a viability rate of over 90%, indicating no toxicity or side effects. The xCELLigence RTCA® showed that at hour 72, there was a significant difference in proliferation in the 0.5 mg/mL PEI/AuNP-siRNA, 0.25 mg/mL PEI/AuNP-siRNA, and 0.125 mg/mL PEI/AuNP-siRNA application groups compared to the control and siRNA groups (p < 0.05). By hour 96, all three groups were statistically different from the control and siRNA groups in terms of proliferation (p < 0.05). Conclusions The results of this analysis suggest that the AuPEI/siRNA complex can be effectively used to silence the target gene, but more studies are needed to verify these results.

Analysis of Spontaneous and Dynamic Imbibition Characteristics of Silica-Based Nanofluid in Microscopic Pore Structure of Tight Oil Reservoirs.

Imbibition behavior plays a crucial role in tight oil reservoir development, to increase tight oil production, a novel sodium lauryl ether sulfate (SLES) nanofluid was developed. Spontaneous and dynamic imbibition performance of nanofluid and the relative influencing factors were systematically investigated using the online low-field nuclear magnetic resonance (LF-NMR) technique. The microscopic mobilization characteristics and mechanism of nanofluid-enhanced matrix crude oil recovery in tight oil reservoirs were further explored. The experimental results showed that the proposed SLES nanofluid achieved the highest imbibition efficiency, and appropriate concentrations of nanoparticle and surfactant were helpful in enhancing the imbibition recovery. Excessive concentrations of chemical agents may block the tiny pores. A reasonable injection rate and shut-in time should be determined to fully leverage capillary forces for water phase imbibition and oil phase displacement as well as the displacement effect of the viscous force and increased water wetness of the rock surface provided by the nanofluid. In addition, NMR T2 cutoff was applied to distinguish the imbibition and displacement regions during dynamic imbibition process. The pore sizes corresponding to the T2 cutoff values after nanofluid and deionized (DI) water flooding were 0.6 and 5 μm, indicating that nanofluid considerably increased the movable crude oil in pores of tight oil reservoirs compared with DI water. Furthermore, imbibition behavior was dominant in micropores (<0.1 μm) and mesopores (0.1-1 μm), and displacement principally occurred in microfractures and macropores. Finally, the underlying mechanisms responsible for nanofluid enhanced oil recovery were related to wettability alteration, capillary pressure, and viscous force. This work provides further understanding of spontaneous and dynamic imbibition when employing nanofluid in tight oil reservoirs.

Preparation and characterization of nanocomposites based on natural rubber/chlorobutyl rubber/graphene nanoparticle: Effect of feeding sequences, mixer type and nanoparticle concentration

AbstractBlends of natural rubber (NR)/chlorobutyl rubber (CIIR) (50/50), along with their nanocomposites containing varying amounts of graphene nanoparticles (GNPs) with and without silane, were prepared using different feeding sequences and mixers. The results indicated that when GNP was first mixed with NR before adding CIIR, the highest GNP content was found in NR; the oxygen permeability and diffusion coefficient decreased significantly by 37% and 55%, respectively. Conversely, when graphene was initially added to CIIR, it was distributed in both rubbers and at the interface, enhancing phase interaction and achieving a finer morphology. This sample exhibited the greatest improvement in mechanical properties due to specific localization of GNP and increased crosslink density. Using an internal mixer instead of a two‐roll mill improved graphene dispersion, reduced curing time, and enhanced mechanical properties. Although the presence of silane reduced graphene dispersion, it improved mechanical and barrier properties due to increased crosslink density. Oxygen permeability was reduced by up to 36% at 3 phr of GNP content with silane. This research proves that the mixing order and the type of mixing equipment are crucial in determining the final performance of rubber composites, as they significantly influence the dispersion and localization of fillers.Highlights NR/CIIR/GNP nanocomposites were prepared by different methods and evaluated. Adding NR/GNP to CIIR led to more presence of GNP in NR and lower permeability. By adding CIIR/GNP to NR, GNP were placed more at interface, modulus improved. Mixing in an internal mixer improved GNP dispersion compared to a two‐roll mill. Silane improved mechanical and barrier properties of NR/CIIR/GNP nanocomposite.

Gamma-ray shielding effectiveness, optical, mechanical, dielectric properties of nanofiller-reinforced PVA/PVP polymeric blend nanocomposites

The aqueous solution cast method was used to create the biodegradable polymer nanocomposite (PNC) films from a blend of poly (vinyl alcohol) PVA and poly (vinyl pyrrolidone) PVP (70/30 wt %) and Fe2O3 nanoparticles (NPs). These PNC films were characterized using X-ray diffraction, scanning electron microscopy SEM, Fourier transform infrared spectroscopy FTIR, and ultraviolet-visible spectroscopy. XRD and FTIR results indicate that Fe+ 3 NPs interact with the host polymer. Optical, electrical, mechanical, and radiation shielding measurements were performed on the PNC films. From the optical measurements, the indirect optical band gap drops from 4.86 eV for the pure blend to 4.26 eV at the greatest NPs concentration. Optical limiting characterization shows that the output power of He-Ne and solid-state green laser beams is reduced from 22.98 to 3.6 mW and 6.59 to 1.4 mW, respectively, when the Fe2O3 NPs content in the blend matrix is increased to 6 wt %. The NGCal software was utilized to calculate nuclear radiation shielding properties. The findings demonstrated that when the concentration of Fe2O3 rose, the PNC films half-value layer and mean free path decreased. Mechanical measurements demonstrate that increasing the Fe2O3 content significantly improves nanocomposite films’ yield and tensile strength. Tensile strength is measured at 27.03 MPa for the composite film containing 6 wt % Fe2O3, which is significantly higher than the 8.66 MPa of the pure (PVA-PVP) film. Compared to the other samples under examination, the 6 wt % Fe2O3 sample yielded the best results (based on the analyzed optical, electrical, mechanical, and radiation shielding properties).

Impact of Thermal Energy on Water and Ethylene Glycol (50:50)-Based Rotating Hybrid Nanofluid Past A Riga Surface with Radiation, Homogeneous and Heterogeneous Reactions

Hybrid nanofluid is crucial in improving the efficiency of heat transmission in thermal engineering applications, particularly the cooling of electrical equipment, heat exchangers, fuel cells, printing machines, etc. This study sought to investigate the augmentation of heat and mass transmission by the use of a rotating hybrid nanofluid consisting of a mixture of gold and silver nanoparticles suspended in water and ethylene glycol (50:50) past a heated Riga surface with velocity slip and suction. The energy equation is constructed using nonlinear radiation and heat consumption. The impact of both homogeneous and heterogeneous processes on the hybrid nanofluid is also explored. The governing mathematical model begins with partial differential equations that are converted into ordinary differential equations using a suitable conversion technique. The results of numerical computations are recorded as graphs and tables using the bvp4c scheme in MATLAB. It is noticed that both directional velocities undergo significant negative changes as a result of enhanced values of the rotational parameter. The higher levels of the radiation parameter resulted in significant enhancements in the thermal profile. The falling behavior of the nanoparticle concentration profile is recorded against a greater quantity of both chemical reaction parameters. Based on our analysis, when the Biot number changes from 0.4 to 0.8, the most significant heat transmission gradient occurs.

Numerical investigation for bioconvection flow of radiative viscoelastic nanofluid with triple diffusion and higher-order slip effects in a porous medium

Owing to enhanced thermal features, the study of nanofluids has become motivating research area which include various applications in renewable energy, thermal management devices, heat exchangers, microelectronics cooling, automotive industry etc. Owing such applications in mind, the aim of current investigation is to present a triple diffusion flow of viscoelastic nanofluid in presence of higher order slip effects. The problem investigates the insight of thermo-diffusion phenomenon with visualization of heat transfer, solutal concentration, nanoparticles concentration and bioconvection applications. The radiative impact with nonlinear relations and heat source are incorporated in the heat equation. The numerical simulations of problem have been performed via shooting scheme. Various applications are claimed with variation of flow parameters. It has been observed that the increase of the slip parameter enhances both the temperature nanofluid and concentration profiles. The solutal concentration profile increases due to Dufour Lewis number. Moreover, the change in nano-Lewis number leads to a decrease of concentration profile.

Influence of MWCNT/ZnO hybrid nanofluids’ thermo-physical characteristics for heat transfer applications

Hybrid nanofluids (HNF’s) can perform as promising heat transfer fluids because of their enhanced thermo-physical characteristics. However, there are certain limitations of using them at higher concentrations. Moreover, lot of works on hybrid nanofluids focussed greatly on assessing thermal conductivity and viscosity. But the other parameters like specific heat and density also play an important role in heat transfer applications in addition to the volume concentration. Also, the effect of the combination of different nano particles on heat transfer is also a crucial area. Hence in this work, it is aimed to determine the thermo-physical characteristics of MWCNT/ZnO hybrid nanofluids (70:30) at varied loading and temperatures. Two step strategy was employed to prepare the (HNF’s) at distinct loadings varying in the range of 0.01%–0.05% and at a range of temperatures of 30°C–70°C with base fluid as water. The mixture’s ratios were 30:70 of MWCNT and ZnO, respectively. HNF’s exhibited an improved thermal conductivity in comparison to the original fluid, which was 80% more than the base fluid. With the rise in the temperature, the density, viscosity and specific heat all trended downward. There is an increase in the density and viscosity with the increase in the volume concentration of the hybrid nano particles. This work suggested that the MWCNT and ZnO hybrid nanofluids are better heat transfer fluids for enhancing the heat transfer and can emerge as efficient coolants for the applications of heat transfer.

Thermophysical Properties of Silicon Oxide Nanoparticles in Water and Ethylene Glycol–Water Dispersions

Measurements of transmission as well as thermophysical properties have been carried out for different concentrations of SiO2 nanoparticles (0, 1, 2, 5, 10, and 20 wt.%) in pure water (W) and ethylene glycol–water mixture (EG/W) in a weight ratio of 25/75, from 298 to 323 K at 100 kPa. In particular, the density, specific heat capacity, and thermal diffusivity are measured by a density meter, differential scanning calorimetry, and the laser flash method. In the case of 20 wt.% SiO2, transmission in the visible range is reduced by 9.3%. Simultaneously, the density rises linearly to 12.3% (in W) and 11.3% (in EG/W). The specific heat capacity decreases to 15.9% (in W) and 17.3% (in EG/W), while the thermal diffusivity rises to 16.4% (in W) and 20.4% (in EG/W). While the density measurements are in very good agreement with the literature, the measured values of the specific heat capacity deviate more than 5%, especially for concentrations below 5 wt.% SiO2. Moreover, it is shown that the thermal conductivity increases less for fluids in small gaps compared to other authors, which could be due to the suppression of the Brownian motion. Based on the measurement results, temperature- and concentration-dependent correlations for the investigated thermophysical properties are developed using two adjustable parameters. In general, these correlations show deviations of less than 4% from the experimental results, which will help to fill the gaps in the variation of experimental results due to size, SiO2 nanofluid production, and different measurement devices, and thus optimize solar thermal applications with SiO2 nanofluid.

Computational study with neural networks to double diffusion in Prandtl thermal nanofluid flow adjacent to a stretching surface design with numerical treatment

The study focuses on the implementation of neural networks in analyzing the behavior of Prandtl nanofluid near a extending surface in the existence of dual diffusion. The research investigates the merged consequence of thermal and concentration gradients on the fluid flow and heat transfer characteristics using advanced computational techniques. The investigation delves into the phenomenon of double diffusion in the flow of Prandtl nanofluid near a stretching surface (DD-PNSS), employing the Levenberg-Marquardt scheme with Artificial Neural Networks (LMS-ANNs). The application of similarity variables converts the non-linear partial differential equations into non-linear ordinary differential equations. Through the application of the Lobatto IIIa formula in a three-stage process, various data sets are generated for the LMS-ANNs by varying parameters such as the Prandtl fluid parameter ([Formula: see text]), Prandtl number (Pr), Brownian motion parameter (Nb), thermophoresis parameter (Nt), and Dufour-solutal Lewis number (Ld). The range of parameter α is from 2 to 3.5, parameter β from 0.1 to 0.9, Nb is from 0.1 to 0.4, Nt is from 0.1 to 0.7, Le is from 1 to 3 and Ld is from 0.1 to 0.5. The intrinsic behavior of embedded parameters on dimensionless velocity, temperature, solutal concentration, and nanoparticle concentration profiles is graphically evaluated. The proposed LMS-ANNs model is meticulously tested, validated, and trained using a multi-stage approach, and its performance is compared to established references to ensure its reliability. The effectiveness of the suggested LMS-ANNs model is further affirmed through regression analysis, Mean Squared Error (MSE) evaluation, and histogram studies, showcasing an exceptional accuracy level ranging from 10−08 to 10−10, setting it apart from alternative approaches and reference models.

Antimicrobial and biodegradable hydrogel based on nanocellulose/alginate incorporated with silver nanoparticles as active packaging for poultry products

In this research, active packaging which was made of all-natural component hydrogels from nanocellulose composited with silver nanoparticles at various concentrations (AgH) was studied. The concentration of silver nanoparticles ranged from 0.0078 to 0.0624 phr. AgH was characterized in terms of basic properties, functional properties, and packaging applications. Biocompatibility testing with the Caco-2 cell line showed that higher concentrations of silver (higher than 0.0312 phr) provided a lower cell viability rate (lower than 70% cell viability). Here, 0.0156 phr of silver nanoparticle concentration was the maximum loading that is safe for the target cell (82% cell viability) and was thus selected for use as active packaging. The antimicrobial activity showed that AgH at all concentrations inhibited both Gram bacteria up to 99.99%. Total volatile basic nitrogen compound testing showed that chicken meat preserved by AgH had the lowest values, indicating that AgH can prolong the shelf life in freshness level 1 (15% TVB-N) for 6.2 days compared to 3.9 and 4.1 days of blank and neat cellulose hydrogel. In addition, all AgH were gradually degraded over time and eventually disappeared within 15–30 days in organic soil.

The Role of Heater Size and Location in Modulating Natural Convection Behavior in Cu-Water Nanofluid-Loaded Square Enclosures

Enhancing the energy efficiency of thermal systems reduces their consumption, lowers costs, and reduces undesired environmental impact, thus making these systems more sustainable. The current work introduces a passive method for heat transfer enhancement that is carried out using natural convection by nanofluid. This work introduces a computational study of the process of natural convection within a square cavity containing Cu/H2O nanofluid. The cavity wall on the left side undergoes partial isothermal heating, while the opposing side is fully cooled isothermally, with all other boundaries maintained adiabatic. A mathematical model formulated based on a 2-D model was used to provide the solution for the system of governing equations of mass, momentum, and energy conservation, employing the finite element technique. A commercial CFD package is utilized to perform the computational simulation. The present investigation delves into the impact of the Rayleigh number, nanoparticle concentration, heater length, and heater location on the flow field and heat transfer characteristics. The model outcomes were displayed for a wide range of the pertinent parameters as 103 ≤ Ra ≤ 106, 0.25 ≤ lh ≤ 1.0, 0.125 ≤ hc ≤ 0.875, and 0.02 ≤ ϕ ≤ 0.10. Also, correlation equations relating the average Nusselt number to these crucial parameters are derived. These equations are simple and can be applied in practice easily in many fields, such as electric and electronic equipment cooling and thermal management of heat sources. Also, these equations gather all the parameters that affect the heat transfer process. They are shedding light on the intricate interplay between these parameters in the natural convection heat transfer process.

Study on the performance of nano boron nitride composite phosphate film modified on carbon steel surface

Purpose The purpose of this paper is to study the effect of nano polypyrrole-modified boron nitride on the performance of phosphate film. Design/methodology/approach By adding polypyrrole-modified boron nitride to the phosphate solution, a phosphate film is formed on the metal surface, improving its corrosion resistance. The effect of different concentrations of polypyrrole-modified boron nitride on the corrosion resistance of Q235 carbon steel surface was studied. The corrosion resistance of the phosphate film was evaluated using the copper sulfate drop test. The electrochemical corrosion performance of the phosphate film was assessed using the weak polarization curve method and electrochemical impedance spectroscopy. The surface of the samples was characterized using scanning electron microscopy and X-ray diffraction analysis. Findings The results show that samples containing polypyrrole-modified boron nitride have a denser and more uniform phosphate film. When the concentration of polypyrrole-modified boron nitride is 0.6 g/L, the drop time of copper sulfate on the formed phosphate film can reach 219 s, which is a 189% increase compared to the performance of the sample without the additive. The current density is 1.06 × 10−6 A/cm2 lower than that of the pure phosphate film, indicating the best corrosion resistance. Polypyrrole-modified boron nitride effectively promotes the formation of the phosphate film. Originality/value This study used the modification of phosphate solution using nanoparticles to investigate the influence of different nanoparticle concentrations on the phosphate film. The corrosion resistance of the phosphate film was enhanced, providing a method and theoretical guidance for the improvement of phosphate solution formulation.

Tribological performance of TiO2 nanoparticle-oil-water emulsion in the hot rolling process

This study aims to evaluate the lubrication performance of a nano-TiO2 oil-in-water (O/W) emulsion during the hot rolling process. A series of O/W emulsions with varying concentrations of TiO2 nanoparticles (0.05, 0.1, 0.3, and 0.5 wt.%) were synthesized. Tribological tests were conducted under a load of 70 N for 10 minutes to determine the optimal concentration based on anti-frictional properties. The O/W nano-emulsion optimized with a 0.1 wt.% concentration of TiO2 applied in the hot rolling process of IS 2062 E250 grade steel. This application resulted in a reduction of rolling force (RF) and surface roughness, suggesting its potential as an alternative lubricant. The results indicated superior antifriction performance at a TiO2 concentration of 0.1 wt.%, leading to a 15% reduction in RF. Additionally, the use of the nano-emulsion contributed to a significant reduction in oxide scale formation. Surface roughness measurements of the rolled samples revealed a 19% decrease, with a roughness value of 2.125 µm, compared to samples rolled with a nano-free O/W emulsion. These findings suggest that nano-TiO2 O/W emulsions could serve as an effective alternative to conventional O/W emulsions in future industrial metalworking applications.

Exploring concentration-dependent transport properties on an unsteady Riga plate by incorporating thermal radiation with activation energy and gyrotactic microorganisms

Abstract The aim of this study is to examine the entropy generation (EG) associated with the transfer of mass and heat in a concentration-dependent fluid with thermal radiation and activation energy, specifically in the context of an unsteady Riga Plate with gyrotactic microorganism. It is important to solve the ordinary differential equations generated from the controlling partial differential equations using Lie symmetry scaling to verify their quality and reliability. The system’s anticipated physical behavior is compared to Mathematica’s Runge–Kutta–Fehlberg numerical solution. Source parameters are essential for validation since they offer accurate results. Methodically change these values as a percentage to determine how they affect the unsteady fluid’s density, mass, and heat transfer over the Riga plate. Velocity, temperature, nanoparticle concentration and microorganism concentration profiles decrease with varying values of the unsteadiness parameter. EG increases with increasing values of concentration difference, thermal radiation, and Reynold number parameters. The Nusselt number experiences a 26.11% rise as a result of radiation when the unsteadiness parameter is A = − 0.25 A=-0.25 , in comparison with the scenario without radiation. Mass transfer upsurges with increasing values of the Brownian motion parameter and reduces with increasing values of thermophoresis parameter. To verify our conclusions, we compare calculated data, specifically the skin friction factor, to theoretical predictions. Tabular and graphical data can show how physical limits affect flow characteristics.

PVDF‐based nanocomposite coatings with superhydrophobic and antibacterial properties on stainless steel surfaces

AbstractIn this study, using a spray‐coating technique, stainless steel surfaces were coated with polyvinylidene fluoride (PVDF) and carbon soot nanoparticles. We imparted various surface properties onto the coatings' surfaces by varying the nanoparticle content and the preparation method. The main aim was to develop antibacterial surfaces by inducing superhydrophobic properties in stainless steel surfaces. In a one‐step preparation method, 5% and 10% of nanoparticles were insufficient to achieve superhydrophobicity, whereas 20% significantly increased the water contact angle to 153°. Morphological evaluations revealed the formation of a nano‐scale structure, which also led to a staggering antibacterial rate of 99.5% against Listeria monocytogenes. Using a two‐step preparation, soot nanoparticles were localized at the coating's top layer, which led to superhydrophobicity at a lower nanoparticle content (10%). However, the bacterial adhesion study showed a lower antibacterial rate (~93%). The difference in bacterial adhesion results was explained by various roughness structures according to the atomic force microscopy results. The developed system has a promising potential to be used as self‐cleaning and antibacterial coatings in the medical and food industries.Highlights Stainless steel surfaces were coated with PVDF and carbon soot nanoparticles Imparted various surface properties onto the coatings' surfaces Developed antibacterial surfaces by inducing superhydrophobic properties Using a two‐step, soot nanoparticles were localized at the coating's top layer Bacterial adhesion study showed a lower antibacterial rate (~93%).

Green synthesis of selenium nanoparticles fromCassia javanica flowers extract and their medical and agricultural applications.

Nanostructured materials are advantageous within numerous fields of medicine owing to their intriguing qualities, which include their size, reactive surface, bioactivity, potential for modification, and optical characteristics. Cassia javanica flower extract was used as a chelating agent in an environmentally friendly process to create SeNPs FTIR, XRD, and TEM, SAED were utilized to analyze and characterize the synthesized. The findings showed that the MIC of Se NPs against B. subtilis and S. aureus was 500µg/ml. Conversely, the MIC for P. aeruginosa, E. coli, and C. albicans were 125, 250, and 62.5µg/ml, respectively. Hence, SeNPs considerably reduced the activity; the inhibition peaked at 77.6% at 250µg/ml to reach 49.04% at 7.8µg/ml. Which showed the greatest suppression of MRSA biofilm formation without affecting bacterial growth. SeNPs showed an intriguing antioxidant capacity, achieving an IC50 of 53.34µg/ml. This study looked how soaking seeds before sowing them with Se NPs at 50, 100, and 200 ppm affected the plants' development in different parameters, as well as their yield of Vicia faba L. The growth conditions were effectively increased by soaking application of various quantities of Se NPs. The highest values of dry weight/pod (g), number of seeds/plant, weight of 100 seeds (g), and number of pods/plant were caused by high concentrations of Se NPs, by 28.43, 89.60, 18.20, and 94.11%, respectively.