Nanoparticles Of Various Shapes Research Articles

Green synthesis of gold nanoparticles using Pelargonium Graveolens leaf extract: characterization and anti-microbial properties (An in-vitro study)

Background In recent years, there has been a notable increase in the level of attention devoted to exploring capabilities of nanoparticles, specifically gold nanoparticles AuNPs, within context of modern times. AuNPs possess distinct biophysical properties, as a novel avenue as an antibacterial agent targeting Streptococcus Mutans and Candida Albicans. The aim of this study to create a nano-platform that has the potential to be environmentally sustainable, in addition to exhibiting exceptional antimicrobial properties against Streptococcus Mutans as well as Candida Albicans. Methods this study involved utilization of Pelargonium Graveolens leaves extract as a cost effective and environmentally sustainable approach for the green synthesis of AuNPs. Subsequently, physicochemical characteristics were assessed employing a variety of analytical methods, including as transmission electron microscopy, X-ray diffraction, Field Emission Scanning Electron Microscope, Zeta potential, Ultraviolet visible absorption spectroscopy, and Energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The antimicrobial efficacy against Streptococcus Mutans and Candida Albicans was evaluated. Nanoparticles of various shapes, including hexagonal, spherical, semi-spherical, and triangular, were synthesized. These nanoparticles exhibited a mean particle size of 294nm and demonstrated low degree of aggregation. These nanoparticles exhibited long-term stability and were capable of facilely combining with diverse bioactive compounds. Results The study demonstrated that AuNPs which is synthesized by green methods display potent antimicrobial properties. Conclusion Utilization of Pelargonium Graveolens AuNPs may exhibit a promising potential as an antibacterial agent against Streptococcus Mutans and Candida Albicans. Nanoparticles (NPs) have the potential to serve as a novel approach for addressing pathogen infections as well as for biomedical, dental and pharmaceutical purposes in the future.

A novel hybridity model for (Cu-Al2O3-H2O) hybrid nanofluid flow with melting heat transfer, shape factor, and irreversibility analysis: A development on Blasius and Sakiadis problems

The mass-based hybrid nanofluid model is applied for the flow over the flat plate with melting heat transfer phenomenon by considering Blasius and Sakiadis problems. Instead of the volumetric concentration of the first and second nanoparticles, the masses of the base fluid and nanoparticles are taken into account. This model is used for the first time to develop the Blasius and Sakiadis problem along with the irreversibility analysis. The nanoparticles of various shapes are also taken for investigation. Appropriate similarity transformations are applied to turn the partial differential equations into ordinary differential equations. To numerically solve the transformed boundary layer equations, the shooting technique with the Runge Kutta–Felhberg scheme was employed. Copper and alumina nanoparticles of two different sorts have been incorporated into the base fluid. The influence of controlling physical factors on the velocity profile, thermal profile, coefficient of skin friction, and Nusselt number for both the Sakiadis and Blasius flows are graphically investigated. In addition, the fluctuation in the entropy generation as well as Bejan number has been illustrated through graphs. In-depth discussion is given regarding the traits of physical and engineering interest.

Automated selection of nanoparticle models for small-angle X-ray scattering data analysis using machine learning.

Small-angle X-ray scattering (SAXS) is widely used to analyze the shape and size of nanoparticles in solution. A multitude of models, describing the SAXS intensity resulting from nanoparticles of various shapes, have been developed by the scientific community and are used for data analysis. Choosing the optimal model is a crucial step in data analysis, which can be difficult and time-consuming, especially for non-expert users. An algorithm is proposed, based on machine learning, representation learning and SAXS-specific preprocessing methods, which instantly selects the nanoparticle model best suited to describe SAXS data. The different algorithms compared are trained and evaluated on a simulated database. This database includes 75 000 scattering spectra from nine nanoparticle models, and realistically simulates two distinct device configurations. It will be made freely available to serve as a basis of comparison for future work. Deploying a universal solution for automatic nanoparticle model selection is a challenge made more difficult by the diversity of SAXS instruments and their flexible settings. The poor transferability of classification rules learned on one device configuration to another is highlighted. It is shown that training on several device configurations enables the algorithm to be generalized, without degrading performance compared with configuration-specific training. Finally, the classification algorithm is evaluated on a real data set obtained by performing SAXS experiments on nanoparticles for each of the instrumental configurations, which have been characterized by transmission electron microscopy. This data set, although very limited, allows estimation of the transferability of the classification rules learned on simulated data to real data.

The Art of Nanoparticle Design: Unconventional Morphologies for Advancing Luminescent Technologies.

The advanced design of rare-earth-doped (RE-doped) fluoride nanoparticles has expanded their applications ranging from anticounterfeiting luminescence and contactless temperature measurement to photodynamic therapy. Several recent studies have focused on developing rare morphologies of RE-doped nanoparticles. Distinct physical morphologies of RE-doped fluoride materials set them apart from contemporary nanoparticles. Every unusual structure holds the potential to dramatically improve the physical performance of nanoparticles, resulting in a remarkable revolution and a wide range of applications. This comprehensive review serves as a guide offering insights into various uniquely structured nanoparticles, including hollow, dumbbell-shaped, and peasecod-like forms. It aims to cater to both novices and experts interested in exploring the morphological transformations of nanoparticles. Discovering new energy transfer pathways and enhancing the optical application performance have been long-term challenges for which new solutions can be found in old papers. In the future, nanoparticle morphology design is expected to involve more refined microphysical methods and chemically-induced syntheses. Targeted modification of nanoparticle morphology and the aggregation of nanoparticles of various shapes can provide the advantages of different structures and enhance the universality of nanoparticles.

Study of surface morphology of Ag thin films prepared by sputtering and irradiation with keV Ar ion beam

In this paper, the possibility of preparing silver nanostructures with a high area density of nanoparticles of various shapes by the ion beam sputtering (IBS) method, using a glancing angle deposition (GLAD) configuration, and subsequent irradiation with heavy ions, was tested. In the experiment, keV Ar+ ions were used for both IBS and bombardment. The prepared nanostructures were analyzed by RBS and microscopic methods of SEM and AFM. It turned out that IBS/GLAD makes it possible to create silver nanostructures (networks of individual silver nanoparticles), but only with relatively low areal densities (∼ 70 µm2). The bombardment led to changes in the porosity only after high ion fluences, but also to disruption of the nanostructures. Even so, the IBS method with GLAD configuration has been shown to be a promising way to prepare high-porosity nanostructures. Nevertheless, further experimental efforts will be needed to find the optimal technology.

Synthesis of silver nanoparticles

The article presents information about plant protection products, methods for the synthesis of silver nanoparticles, stabilization of the resulting solutions, and the morphology of the resulting colloidal solution. The chemical synthesis of silver nanoparticles was carried out in the presence of reducing agents and stabilizers. Silver nitrate was used as a source of silver, and glucose, sodium citrate and hydrazine were used as reducing agents; water-soluble polymers were used as stabilizers - polyvinylprolidone, polyvinyl alcohol and polyvinyl acetate. Under optimal conditions, stable silver nanoparticles with different color solutions were obtained. An increase in the color intensity of solutions is associated with the dispersion of silver nanoparticles. The shape and size of silver nanoparticles are directly dependent on the concentration of solutions, the nature of stabilizers, reducing agents and temperature. By controlling the reaction conditions, it is possible to synthesize silver nanoparticles of various shapes and sizes. The relationship between the shapes and sizes of nanoparticles, the concentration of silver salt, temperature and the nature of the stabilizer is indicated. The resulting nanosilver is recommended for use in agriculture.

Convective nanofluid flow subjected to variable porosity, inclined magnetic field, and thermal radiations

Nanofluids pique the attention of researchers and scientists because of their excellent thermal transfer rates. They have numerous technological and industrial implementations in daily life. Nonsimilar analysis in this research is performed to study the consequences of nonuniform porosity of a porous medium on the radiative flow of nanofluid across a vertically positioned stretching surface. Moreover, the effects of viscous dissipation and inclined magnetic field are also taken into account. Single phase nanofluid model with latest thermophysical features of nanofluid are considered to devise the physical problem. Hamilton–Crosser model is used to investigate the various shapes of nanoparticles. Titanium oxide (TiO 2), Zirconium dioxide (ZrO2 ), water and Borosilicate ceramic are regarded as nanoparticles, base fluid, and porous media, respectively. The Brinkman–Forchheimer-extended Darcy model is assumed to represent the flow through porous medium. The governing partial differential equations (PDEs) with accompanying boundary conditions are transformed into the dimensionless system by deploying the appropriate transformations. The local nonsimilarity (LNS) approach with MATLAB bvp4c algorithm is executed to solve the dimensionless nonlinear coupled differential system. Results demonstrate that the augmentation in Hartmann number and porosity parameter diminished the velocity profiles of the considered nanofluids. Moreover, maximum temperature profile is noticed for the lamina shaped nanoparticles. Local Nusselt number for considered cases diminishes against the augmented estimations of Richardson number, radiation parameter and nanoparticles shape factor. A comparative study between the current study and previously published results for a specific case is conducted to validate the results, and good agreement is found between them.

Combinatorial Approach to Find Nanoparticle Assemblies with Maximum Surface-Enhanced Raman Scattering.

Plasmonic nanoparticles exhibit unique properties that distinguish them from other nanomaterials, including vibrant visible colors, the generation of local electric fields, the production of hot charge carriers, and localized heat emission. These properties are particularly enhanced in the narrow nanogaps formed between nanostructures. Therefore, creating nanogaps in a controlled fashion is the key to achieving a fundamental understanding of plasmonic phenomena originating from the nanogaps and developing advanced nanomaterials with enhanced performance for diverse applications. One of the most effective approaches to creating nanogaps is to assemble individual nanoparticles into a clustered structure. In this study, we present a fast, facile, and highly efficient method for preparing core@satellite (CS) nanoassembly structures using gold nanoparticles of various shapes and sizes, including nanospheres, nanocubes (AuNCs), nanorods, and nanotriangular prisms. The sequential assembly of these building blocks on glass substrates allows us to obtain CS nanostructures with a 100% yield within 4 h. Using 9 different building blocks, we successfully produce 16 distinct CS nanoassemblies and systematically investigate the combinations to search for the highest Raman enhancement. We find that the surface-enhanced Raman scattering (SERS) intensity of AuNC@AuNC CS nanoassemblies is 2 orders of magnitude larger than that of other CS nanoassemblies. Theoretical analyses reveal that the intensity and distribution of the electric field induced in the nanogaps by plasmon excitation, as well as the number of molecules in the interfacial region, collectively contribute to the unprecedentedly large SERS enhancement observed for AuNC@AuNC. This study not only presents a novel assembly method that can be extended to produce many other nanoassemblies but also identifies a highly promising SERS material for sensing and diagnostics through a systematic search process.

Heat transfer characteristics of rectangular/triangular/convex-shaped fins filled with hybrid nanoparticles under dry and wet conditions

Numerous researchers have been interested in nanofluids because of their improved thermal characteristics and heat transmission capabilities. Recently, it has been possible to create a novel nanofluid with exceptional thermal properties by combining ternary nanoparticles of various shapes. In this respect, it is believed that the thickness of the fin will change with the length of the fin and that the impacts of thermal radiation, convection on a heat transfer mechanism, and internal heat production in a fin wetted with ternary hybrid nanofluid will depend on the length of the fin. As a result, several fin profiles, including triangular, convex, and rectangular, have been taken into consideration. This study also investigates the comparison of heat and thermal energy fluctuations in both wet and dry conditions. In order to examine the porous nature, Darcy's model is required. With the aid of the Maple computer program, the resultant nonlinear partial differential equation and boundary conditions are non-dimensionalized and numerically resolved using the implicit finite difference approach, the graphic explanation of fin efficiency, and transient thermal response for different values of the essential parameters. The investigation yielded the novel discovery that the effectiveness of the fins is enhanced by the presence of a ternary hybrid nanofluid. Three fins with varied shapes have been compared in both wet and dry circumstances. The study has discovered that triangular fins have a quicker rate of temperature decline, whereas rectangular fins have a greater efficiency. The investigation's results have a significant impact on improving heat transmission in industrial operations.

ТЕРМОДИНАМИЧЕСКИЙ АНАЛИЗ ПРОЦЕССА ФОРМИРОВАНИЯ НАНОСТРУКТУРНОГО ПОЛИКРИСТАЛЛИЧЕСКОГО МАТЕРИАЛА НА ОСНОВЕ НАНОАЛМАЗОВ, МОДИФИЦИРОВАННЫХ НЕАЛМАЗНЫМ УГЛЕРОДОМ (ЧАСТЬ 1)

The influence of the size of carbon particles on the parameters of the graphite–diamond phase transformation is considered. It is shown that the surface energy of carbon nanoparticles of various shapes (spherical, columnar) makes a significant contribution to their total thermodynamic potential, which leads to a shift in the diamond–graphite equilibrium curve to the low pressure region and an expansion of the diamond phase stability region. At the same time, the change in the chemical potential (Gibbs free energy) during the direct (not catalytic) transition of thin-film graphite-like nanostructures into diamond will be higher than for “massive” graphite, which leads to an increase in the pressure of phase transformation into diamond. To reduce the parameters of diamond formation and obtain nanostructured diamond polycrystals, it is proposed to use nanodiamond particles with a nanometer surface layer of non-diamond (graphitelike) carbon as the starting material. In this case, the nanodiamond surface will influence the transition of a nanometer layer of graphite (graphite-like carbon) into diamond under more favorable thermodynamic parameters.

Magneto-thermogravitational convective flow and thermal behavior of hybrid nanoliquid in a novel T-shaped wavy chamber considering various shapes of nanoparticles

Magneto-thermogravitational convective flow and thermal behavior of hybrid nanoliquid in a novel T-shaped wavy chamber considering various shapes of nanoparticles

Enhanced thermal conductivity in Ag-H2O nanofluids by nanoparticles of different shapes: Insights from molecular dynamics simulation

The mechanism of thermal conductivity enhancements and influential factors make a lot of sense in the intensive investigation of nanofluids. While numerous studies have explored the effect of solid–liquid interfacial layers on thermal conductivity improvement in water-based nanofluids with diverse applications, investigations into the intrinsic mechanisms underlying interfacial layers in relation to nanoparticle shape remain limited. The thermal conductivity of water-based Ag-H2O nanofluids was investigated using molecular dynamics simulations of non-equilibrium molecular dynamics (NEMD), with emphasis placed on the shape and volume fraction of nanoparticles. The influence of nanofluid volume fraction on thermal conductivity was revealed through visual analysis of 3D smoothed surface plots, highlighting the positive correlation between thermal properties and increasing volume fraction of nanoparticles. Moreover, the contribution of different shapes of silver nanoparticles to thermal conductivity enhancement demonstrated an increasing trend with the corresponding growth in surface-to-volume ratio (S/V values associated with different particle shapes). For the volume fraction of 1.5%, the minimum thermal conductivity enhancement of 22.75% was observed for the spherical shape, while the maximum thermal conductivity enhancement of 25.51% was achieved with the triple-platelet particles. Importantly, the comprehensive analysis of radial distribution function (RDF) and mean square displacement (MSD) indicated the positive effect of interfacial nanolayers influenced by nanoparticles of various shapes on the thermal conductivity of nanofluids. This study provides valuable insights into the impact of nanoparticle shape on the thermal properties of nanofluids, opening up promising prospects for future molecular dynamics simulations.

Heat and mass transfer with entropy optimization in hybrid nanofluid using heat source and velocity slip: a Hamilton–Crosser approach

The modeling and analysis of hybrid nanofluid has much importance in industrial sector where entropy optimization is the key factor in different processes. This mechanism is also used in medical industry, where it can be used for separation of blood cells (red and white blood cells, platelets and plasma) by centrifuge process, treating cancers, and drug transport. In light of this importance, current study is focused on mathematical modeling and analysis of blood based hybrid nanofluid between rotating disks with various shapes of nanoparticles. The shape factors are taken into account with Hamilton–Crosser model as spherical, brick, cylinder and platelet in the current scenario, with special reference to entropy optimization. In order to solve modeled nonlinear and non-dimensional system, optimal homotopy analysis approach is utilized through Wolfram MATHEMATICA 11.3 software. Error estimation and convergence analysis confirms that obtained semi-analytical solutions are valid and reliable. Velocity, temperature and concentration profiles are analyzed against important fluid parameters. Fluid velocity decreased in all directions when unsteady parameter mathbb {B} and Darcy number Da increased while the slip parameters zeta _{1} and zeta _{2} decreased the nanofluid velocity. It is observed that in case of brick shaped nanoparticles, fluid temperature is enhanced as compared to other shape factors in the study. Minimal entropy generation is captured in case of spherical nanoparticles, while highest heat transfer is observed in platelet shaped nanoparticles. Furthermore, numerical optimization of entropy is performed against different values of hbar and volume fractions varphi _{Rd} and varphi _{Al}. Minimized entropy is recovered to be zero when hbar =-0.6, varphi _{Rd}=2% and varphi _{Al}=1%.

Langmuir-Blodgett-Mediated Formation of Antibacterial Microneedles for Long-Term Transdermal Drug Delivery.

Microneedles (MNs) have become versatile platforms for minimally invasive transdermal drug delivery devices. However, there are concerns about MN-induced skin infections with long-term transdermal administration. Using the Langmuir-Blodgett (LB) technique, a simple method for depositing antibacterial nanoparticles of various shapes, sizes, and compositions onto MNs is developed. This strategy has merits over conventional dip coating techniques, including controlled coating layers, uniform and high coverage, and a straightforward fabrication process. This provides MNs with a fast-acting and long-lasting antibacterial effect. Thisstudy demonstrates that antibacterial MNs achieve superior bacterial elimination in vitro and in vivo without sacrificing payload capacity, drug release, or mechanical strength. It isbelieved that such a functional nanoparticle coating technique offers a platform for the expansion of MNs function, especially in long-term transdermal drug delivery fields.

Heat Transfer Characteristics on MHD Oscillatory Radiative Nanofluid with H2O/C2H6O2 (Basefluid): A Comparative Study of Different Nanoparticles of Various Shapes

Heat Transfer Characteristics on MHD Oscillatory Radiative Nanofluid with H2O/C2H6O2 (Basefluid): A Comparative Study of Different Nanoparticles of Various Shapes

Synthesis and Characterization of Iron Oxide Nanoparticles by Murraya Koenigii leaves

Nanotechnology becomes the most interesting area for researchers from last two decades. There are several methods to synthesis nanoparticles but the use of green method for synthesis reduces or eliminates the generation of hazardous byproducts. Green synthesis method is environment friendly alternative to conventional synthesis techniques. Green chemistry is about reducing risk, energy, environmental impact, hazard, cost, materials and waste. The green method or biological method involves the use of microorganisms, plants etc. for synthesis of nanoparticles. In our present research work we use Murraya koenigii leaves powder extract as reducing and capping agent. Plant sources containing the phytoconstituents viz., Tannins, Alkaloids, Polyphenols, Flavonoids, Citric acid etc. Metallic and metal oxides nanoparticles of various shapes, sizes, contents and physicochemical properties can be synthesized using green synthesis method. The synthesized Iron oxide Nanoparticles were characterized be different analytical techniques. The surface morphology revealed by SEM, elemental composition by EDX, Different functional groups revealed by FTIR spectroscopy and particle size measured by particle size analyzer.

Entropy generation analysis of hybrid nanofluid through flexible tube with convective conditions

Entropy generation analyses of hybrid nanofluids via compliant wall tubes are performed with peristalsis effects in this study. Thermophysical properties of nanofluid are incorporated in mathematical formulations for various shapes of nanoparticles. Convective conditions on the boundary are considered. Momentum and energy equations are modeled and simplified under the lubrication approach. Solutions are calculated numerically using MATHEMATICA. The impact of various related parameters on flow quantities is observed via graphs. The study reveals greater entropy generation for blade-shaped nanoparticles.

Chiral Plasmonic Response of 2D Ti3C2Tx Flakes: Realization and Applications

AbstractThe circularly polarized light sensitive materials response can be reached at plasmon wavelengths through the coupling of intrinsically non‐chiral plasmonic nanostructure with chiral organic molecules. As a plasmonic background, the different types of metal nanoparticles of various shapes and sizes are successfully tested and an apparent circular dichroism (CD) signal is measured in both, nanoparticles suspensions and after nanoparticle immobilization in substrate. In this work, the creation of plasmon‐active 2D flakes of MXenes (Ti3C2Tx) is proposed, with the apparent CD response at plasmon wavelength, through the coupling of intrinsically non‐chiral flakes with helically shaped helicene enantiomers. This work provides the first demonstration of chiral and plasmon‐active 2D material, which shows the absorption sensitive to light intrinsic circular polarization even in plasmon wavelengths range. The appearance of the induced CD signal is additionally confirmed by several theoretical calculations. After the experimental and theoretical confirmation of the optical chirality at plasmon wavelengths, the flakes are utilized for the polarization sensitive conversion of light to heat, as well as for polarization dependent triggering of plasmon‐assisted chemical transformation.

Nanogeochemistry of karst-type bauxite from Jingxi, Guangxi, China: Revealing a new occurrence of Al, Si, Ti, Fe, and C by nanoparticles in karst-type bauxite deposit

Karst-type bauxite deposits are an essential source of bauxite. Due to their massive reserves, they have aroused the world's attention. However, there is still controversy about migrating critical elements (such as Si and Al) in bauxite. Various significant nano-mineral particles are discovered in the Jingxi bauxite deposit using transmission electron microscopy (TEM), revealing karst-type bauxite deposits' intricate metallogenic process. These nano-mineral particles provide insight into the occurrence state of ore-forming materials and the element's migration mechanisms using the microscopic nano-geosciences approach. The Jingxi deposit's bauxite samples were discovered to contain many nanoparticles of various shapes and sizes (30–50 nm and over 500 nm), including columnar, granular, and layered forms. These nanoparticles were identified through morphological, chemical, and lattice spacing analyses as scaly diaspore aggregates, columnar rutile particles, layered assemblages of graphite, and kidney-shaped goethite particles. The aluminium silicate mineral (Al, Si, and O) nanoparticles showed in-depth information about the origin of bauxite deposits’ raw materials and endowed a nanometer basis for studying the difficult-to-migrate elements: Al and Si. These nanoparticles confirm an alkaline and reductive metallogenic environment and present nanogeoscience confirmation that igneous rocks are one source of ore-forming components for bauxite.

Basics of the LSPR Sensors for Soft Matter at Interfaces

An important class of localized surface plasmon resonance (LSPR)–based sensors implies the fabrication of an array of plasmonic metal nanoparticles on the support in combination with a thin protective dielectric layer. If needed, this layer can be covered, e.g., by a suitable thin biological layer, e.g., a lipid bilayer with receptors. The attachment of analyte (e.g., protein molecules or vesicles) to such interfaces is tracked via its indirect optical effect on the LSPR-related peak extinction wavelength. Such sensors have been commercialized and are now used to study biological soft matter. The length scale of the local field able in probing analyte around plasmonic nanoparticles is in this case on the order of 20 nm. Conceptually, these LSPR sensors are similar to the SPR sensors which were developed much earlier. Herein, the similarities and differences in the formalisms used to interpret SPR and LSPR measurements are discussed in detail. In particular, the exponential and power-law attenuation functions employed in these formalisms to describe the drop of the field are compared from various perspectives. The applicability of the power-law attenuation function in the context of LSPR is illustrated by using a generic model describing spherically shaped plasmonic metal nanoparticles. This model is also employed to illustrate the sensitivity of LSPR sensors with respect to various quantities. Among more specific results, the available expressions for the signal reduction factor for analyte nanoparticles of various shapes are collected and complemented by new ones. In addition, the equation describing the LSPR signal related to analyte attachment to a rough surface is presented.