Nanoparticles Of Different Shapes Research Articles

Green method synthesis of silver nanoparticles from Ficus religiosa plant leaves extract and their evaluation for anti-cancer activity in Human Lung Adenocarcinoma A549 cells

Due to low surface area and minimum possible state of energy, spherical nanoparticles are preferable over nanoparticles of other shapes. Use of nanoparticles in cancer therapy is an emerging field with wide varieties of applications. But, to retain within the cell for optimum anticancer activity, synthesized nanoparticles are required to be in proper shape and size. Plant phytochemicals reduce and cap metal ions to produce nanoparticles of different shapes and sizes. In this study, silver nanoparticles were synthesised using Ficus religiosa plant leaves aqueous extract. Synthesised material was characterised using Scanning electron microscopy (SEM), Energy dispersive X Ray analysis (EDAX), Transmission Electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy techniques. FTIR analysis showed presence of varied phytochemicals. SEM analysis of the sample elucidated morphological characteristics of the material while elemental analysis through EDAX technique reported silver metal ions in synthesised sample. TEM analysis confirmed nanoparticles size ranging from 21-27 nm. Result of the study showed decreased cell viability of A549 cells when treated with the green method to synthesise silver nanoparticles.

A numerical inquiry of the MHD radiative thin film nanofluid flow and heat transfer augmentation for Ni and Ta nanoparticles of different shapes dispersed in C 12 H 26–C 15 H 32 over an unsteady, curved stretching surface

Thin films are a versatile technology used in various industries, including light-emitting diodes, magnetic recording media, electronic device manufacturing, and optical coating. They are crucial for studying quantum phenomena, superlattices, and multiferroic materials. Their small size allows for better thermal transport studies due to the combination of thin film flow and nanoparticles. Therefore, this study aims to investigate thin film flow and heat transfer with the effects of thermal radiations, magnetic field, and velocity slip in association with tantalum ( Ta ) and nickel ( Ni ) nanoparticles that emerged in kerosene oil ( C 12 H 26 − C 15 H 32 ) toward a curved stretching surface. A review of the pertinent literature indicates that no research has previously been done on the present problem of an unsteady thin film flow across a curved stretching surface. The problem under consideration is modeled by choosing the curvilinear coordinate system. The controlling nonlinear system of partial differential equations is transformed into the system of ordinary differential equations by using an appropriate similarity transformation and then solved numerically using the BVP 4 C technique in MATLAB . The impact of significant physical parameters on velocity, temperature, skin friction, and Nusselt numbers are depicted through graphs and radar charts. The investigation highlights the significant influence of magnetohydrodynamics ( MHD ) , thermal radiation, volumetric fraction, and velocity slip on the enhancement of nanofluid temperature. It is also noted that cylindrical-shaped Ta nanoparticles exhibited the maximum velocity, while blade-shaped Ni nanoparticles showed the lowest. Moreover, the maximum and minimum temperatures were observed for blade-shaped Ni nanoparticles and cylindrical Ta nanoparticles, respectively. Additionally, the maximum and minimum values of skin friction are found for cylindrical Ni nanoparticles and blade-shaped Ta nanoparticles, respectively. Similarly, the maximum and minimum Nusselt numbers are recorded for cylindrical Ta nanoparticles and blade-shaped Ni nanoparticles, respectively.

Numerical simulation of unsteady blood based Carreau nanofluid flow in an inclined porous saturated artery having overlapping stenosis with electro-osmosis

The present paper focuses on the computational modeling of the unsteady non-Newtonian electro-magnetohydrodynamic flow of nano-blood through the inclined and tapered saturated porous artery with overlapping stenosis. The Carreau fluid model is adopted to simulate the non-Newtonian behavior of the blood. This study also uses a modified form of Darcy’s law applied to the Carreau model. Blood is doped with a suspension of homogeneous biocompatible nanoparticles of different shapes. In addition, a combination of a magnetic field and an electric field has also been taken into account. The significance of this work rests in the ability to enhance comprehension of the complicated behavior of hemodynamic flow when exposed to external fields and porous media with the addition of nanoparticles, which has substantial implications for the regulation and treatment of cardiovascular diseases. The finite-difference method is used to obtain the solution of the resulting equations. The simulations are applicable to targeted magnetic therapy for stenotic artery disease and the delivery of nanomedicines.

Synergistic influence of external electric field on laser ablation in liquid: correlating nanoparticle synthesis and cavitation bubble dynamics

The present study aims to investigate the changes in the properties of nanoparticles (NPs) and cavitation bubble dynamics by applying an external electric field during laser ablation in liquid (LAL). Investigating electric field assisted laser ablation in liquid (EFLAL) is crucial since phenomena such as plasma charging effect and electrostatic pressure have important role in determining the size, shape, and crystallinity. of the NPs. With this motivation, the present study has been conducted with different electric fields of 0, 100, 500 and 1000 V cm−1 to probe the effect of an external electric field on the dynamics of EFLAL. The charging effect observed on NPs during cavitation bubble dynamics was also investigated at these field intensities. The size of NPs witnesses a reduction from ∼30 nm without electric field to ∼19 nm in presence of electric field. Also, a significant narrowing of the size distribution by over 4 times was observed in the presence of electric field. This clearly demonstrates that EFLAL can be used to obtain NPs with uniform size distribution. Moreover, NPs of different shapes have also been observed by varying the electric field intensities (100 and 1000 V cm−1). The effect of the external electric field on the dynamics of the cavitation bubble produced during EFLAL has been probed using shadowgraphy technique. It has been observed that the bubble size increases with the presence of an electric field. The estimation of the bubble pressure in the presence of an electric field has revealed that the implosion bubble pressure is significantly lower than pressure in the absence of the field. The results obtained for NPs have been correlated to the changes in bubble parameters in this work.

Impact of Plant Extract Phytochemicals on the Synthesis of Silver Nanoparticles.

This work aims to analyze the influence of selected plants on the synthesis of silver nanoparticles (AgNPs). Six plants were chosen for the experiment, from which extracts were prepared: maclura fruit, spruce and ginkgo needles, green algae (Ch. kessleri), and mushrooms, namely Collybia nuda, and Macrolepiota procera. The composition of the extracts and colloids after preparation of the nanoparticles was analyzed using FTIR analysis. The composition of the extracts affected not only the rate of the synthesis but also the shape of the nanoparticles. TEM analysis confirmed the synthesis of mainly spherical nanoparticles (size range: 10-25 nm). However, triangular prisms and polyhedral nanoparticles synthesized by the extracts containing mainly flavonoids, terpenes, and phenols (the main compounds of resins) were also confirmed. EDS analysis was used to analyze the composition of the nanoparticles. It was proven that by choosing the right plant extract and using the appropriate technology with extract treatment, it is possible to prepare nanoparticles of different shapes.

Biological structural study of emerging shaped nanoparticles for the blood flow in diverging tapered stenosed arteries to see their application in drug delivery

The magnetic force effects and differently shaped nano-particles in diverging tapering arteries having stenoses are being studied in current research via blood flow model. There hasn’t been any research done on using metallic nanoparticles of different shapes with water as the base fluid. A radially symmetric but axially non-symmetric stenosis is used to depict the blood flow. Another significant aspect of our research is the study of symmetrical distribution of wall shearing stresses in connection with resistive impedance, as well as the rise of these quantities with the progression of stenosis. Shaping nanoparticles in accordance with the understanding of blood flow in arteries offers numerous possibilities for improving drug delivery, targeted therapies, and diagnostic imaging in the context of cardiovascular and other vascular-related diseases. Exact solutions for different flow quantities namely velocity, temperature, resistance impedance, boundary shear stress, and shearing stress at the stenosis throat, have been assessed. For various parameters of relevance for Cu-water, the graphical results of several types of tapered arteries (i.e. diverging tapering) have been explored.

Synthesis and characterization of zinc oxide nanoparticles

Zinc Oxide (ZnO) nanoparticles were synthesized by hydrothermal method and analyzed for various properties. Analysis of the XRD spectra of the synthesized nanoparticles showed 46 % crystalline zincite and the average grain size was calculated to be around 39.63 nm, studies of the FTIR spectra measured over the range between 4000–500cm−1 proved the presence of Zn Obonding of the synthesized nanoparticles at 734.26 to 1473.71 cm1 .SEMimage of the synthesized nano particles showed the formation of agglomerated nanoparticles of different shapes whose size are within the nanometer range while, cyclic voltamo gram of the immobilized ZnO nanoparticles on GCE also showed significant increase in redox peak current when compared to the bare (unimmobilized) GCE. It can be concluded from the obtained results that ZnO nanoparticles have been successfully produced which can be used to improve the performance of electrochemical sensors. Keywords :- XRD analysis, FTIR studies, SEM image analysis, Cyclic voltammogram

(Invited) Integration of Functional Nanostructures and Nanoparticles into Micro- and Nanoelectronic Components and Systems

In recent decades, there has been a significant evolution of microelectronic and semiconductor technologies towards the nanoscale. Both bottom-up and top-down integration concepts of functional nanostructures and nanoparticles into micro- and nanofabricated electronic components have become critical issues that decisively affect the performance of smart electronic systems in various application areas such as environmental sensing and energy harvesting.Functional nanostructures and nanoparticles of different shapes, sizes, morphologies, and materials are now used in various technical and industrial applications, medicine, pharmacy, biology, electronics, power engineering, ecology, and many other fields. However, the complex engineering challenge here is the integration of functional nanostructures, such as molecular components (e.g., functional self-assembled molecular monolayers or entities of desoxyribonucleic acid, DNA), organic or inorganic nanoparticles (metal, semiconductor, colloidal materials), or similar building blocks into nanolithographically fabricated environments.Manufacturing paradigms for this integration go beyond current CMOS- and MEMS-fabrication schemes. Scale-bridging and hybrid manufacturing schemes that combine established top-down manufacturing techniques for microelectronic devices, including aspects of nanotechnology, with bottom-up nanoassembly of molecules on unstructured and pre-structured substrates are required. Microsystems technology based on the combination of conventional semiconductor processing with biotechnological approaches has thus become an emerging field with manifold applications, especially in the field of sensor technology.This contribution describes two illustrative and innovative research questions in nanopatterning and system integration at the micro-nano-interface to motivate applications with new and unprecedented functionalities. The first research question focuses on network-based biocomputing (NBC) using biological agents driven by biomolecular motor proteins in a lithographically fabricated nanofluidic channel system. This approach opens up opportunities for energy-efficient solutions to complex mathematical problems as they make their way through the NBC network. Methods are required to create switchable and rewritable nano-networks to address different mathematical problems using a single NBC-chip. Therefore, stimuli-responsive materials must be selectively and locally deposited into the nano-network to control the transport of the filaments through the network.The second research question focuses on nanophotonic devices based on DNA origami. The high-precision arrangement of nanoscopic substructures using specific binding sites (capture ends) of the DNA origami enables the precise arrangement of DNA origami functionalized with individualized metal nanoparticles. This arrangement could be used to exploit individual spectral response mediated by plasmonic effects.From a technological perspective, top-down lithographic nanostructuring technologies and bottom-up nanostructuring technologies are the basis for new device concepts. The adaptability of nanostructures to the world of biological molecules and other nanoscopic building blocks such as quantum dots and nanoparticles enables novel, even personalized, devices and engineering solutions.

Analysis of Brownian motion trajectories of non-spherical nanoparticles using deep learning

As nanoparticles are being put to practical use as useful materials in the medical, pharmaceutical, and industrial fields, the importance of technologies that can evaluate not only nanoparticle populations of homogeneous size and density but also those of rich diversity is increasing. Nano-tracking analysis (NTA) has been commercialized and widely used as a method to measure individual nanoparticles in liquids and evaluate their size distribution by analyzing Brownian motion. We have combined deep learning (DL) for NTA to extract more property information and explored a methodology to achieve an evaluation for individual particles to understand their diversity. Practical NTA always assumes spherical shape when quantifying particle size using the Stokes–Einstein equation, but it is not possible to verify whether the measured particles are truly spherical. We developed a DL model that predicts the shape of nanoparticles using time series trajectory data of BM obtained from NTA measurements to address this problem. As a result, we were able to discriminate with ∼80% accuracy between spherical and rod-shaped gold nanoparticles of different shapes, which are evaluated to have nearly equal particle size without any discrimination by conventional NTA. Furthermore, we demonstrated that the mixing ratio of spherical and rod-shaped nanoparticles can be quantitatively estimated from measured data of mixed samples of nanoparticles. This result suggests that it is possible to evaluate particle shape by applying DL analysis to NTA measurements, which was previously considered impossible, and opens the way to further value-added NTA.

Interplay of geometry and shape-engineered-nanoparticles for efficient thermal performance in forced convection-based electronic cooling

Efficient and lightweight heat sinks for microelectronic cooling are pivotal for developing energy-efficient next-generation devices with huge processing power and significant heat dissipation over small scales. Microchannel heat sinks offer a solution not only for cooling electronics but also in applications of energy harvesting, defense, and biomolecular dynamics. An accurate understanding of transport phenomena at these scales can guide us toward minimizing frictional losses and thermal entropy for efficient thermal management. In this study, we numerically investigate the hydrothermal characteristics of a wavy microchannel heat sink integrated with nanofluids containing nanoparticles of different shapes. Our primary objective is to enhance thermal performance by studying the effects of four distinct nanoparticle shapes: spheres, cylinders, platelets, and blades. The nanoparticle concentration is varied within the range of 0.02–0.08, while the Reynolds number is set within the laminar regime (200–800). By decoupling the different contributions to system entropy and exergy, we aim to gain insights into the underlying physics behind thermal performance enhancement using shape-based nanofluids. Our findings reveal a significant increase in convective heat transfer coefficient, up to 50.63%, as well as notable exergy savings of up to 65.56%.

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.

Quantum optimal control theory for a molecule interacting with a plasmonic nanoparticle

In this work, we extend the quantum optimal control theory of molecules subject to laser pulses to the case of molecules close to plasmonic metal nanoparticles. Explicitly including the nanoparticle dielectric response in the system Hamiltonian, the electronic dynamics for the molecule in the presence of the laser pulse is coupled with the polarization dynamics of the nanoparticle itself. A characteristic feature of a plasmonic environment is that it both amplifies the laser pulse field and introduces nonlocal time effects (a behavior of inherent interest for the quantum optimal control theory), impacting on the shape of the optimized light pulse. The optimal control theory is formulated using a genetic algorithm; numerical examples of a target molecule and nanoparticles of different shapes are presented and discussed.

A green synthetic approach for the morphological control of ZnO-Ag using β-cyclodextrin and honey for photocatalytic degradation of bromophenol blue

Green synthetic approaches aid control of physicochemical properties of nanoparticles and decrease the environmental footprint of the nanoparticles. Herein, novel synthesis of ZnO nanoparticles (NPs) using natural surfactants and sequential investigation of their optical, physicochemical and photocatalytic properties are conducted. This work utilizes β-cyclodextrin (βCD) and honey as surfactants during the production process. It is demonstrated that these natural surfactants have the ability to control size, shape, crystalline phase growth and dispersion of NPs (denoted as ZnO-C and ZnO-H). Subsequent coupling of ZnO NPs with Ag to form the binary nanostructures (ZnO-xAg, ZnO-C-xAg and ZnO-H-xAg) further assists controlling their physicochemical properties. With a variation of Ag NPs loading, the 3 wt% Ag loaded nanophotocatalysts were more efficient and their associated properties were revealed by various characterization techniques. Nanoparticles of different shapes were fabricated with a surface area of up to 10 m2.g−1 and crystalline sizes of 9.38 nm. Photoluminescent spectroscopy indicated that Ag nanoparticles enhanced the life span of electron-hole pairs. Thus, photodegradation of bromophenol blue (BPB) indicated enhanced NPs photoactivity upon modification with CD, honey, and Ag NPs. BPB photodegradation was > 99.84% using ZnO-H-3Ag with reaction rates of k0app=518.8×10−2min−1 and up to 75% total organic carbon was removed by ZnO-H-3Ag at a rate of 8.19×10−3min−1.

Synthesis of α-Amino Acids via Electrochemical Fixation of CO2 to Imines Using Different Metal Cathodes

The electrochemical fixation of CO2 by imines has recently attracted an increased interest as sustainable strategy for the synthesis of α-amino acids and a green alternative to the traditional Strecker synthesis, which relies on highly toxic precursors. Despite the industrial prospects of the electrochemical approach, the catalyst material effects on the selectivity of the process are still purely understood, hindering rational catalyst design. Herein, we study the electrochemical fixation of CO2 by N-benzylideneaniline using a wide variety of cathode materials, including 10 polycrystalline metals (Ti, Zn, Au, Pd, Pt, Sn, Ag, Ni, Fe, Cu), glassy carbon, and Pd nanoparticles of different shapes. We found that among all studied bulk metals, Ti and Zn show the best results with above 93% faradaic efficiency of α-amino acid, while other materials show from good to low selectivity (12% for Sn). We also demonstrate that especially high current densities and nearly quantitative faradaic efficiency and selectivity of α-amino acids can be achieved by employing Pd nanoparticles.

Quantitative Analysis of the Shape Effect of Thermoplasmonics in Gold Nanostructures.

The shape effect of thermoplasmonic properties of Au nanostructures remains largely unexplored. Herein, we report a systematic investigation on the photothermal effects of Au nanoparticles (NPs) of different shapes: nanosphere, nanocube, nanorod, nanostar, and nanobipyramid. The Joule (Jo) number (absorption cross section normalized by the particulate volume) is utilized for quantitatively assessing the photothermal properties of these different shaped Au NPs. It is shown that the Jo number of Au NPs greatly varies with the geometric shape and localized surface plasmon resonance (LSPR) wavelength. Specifically, the Jo number decreases with the red-shifting of the LSPR wavelength in these Au NPs, and the Au NPs of sharp structural features such as Au nanorod, nanostar and nanobipyramid have a much larger Jo number, indicative of their exceptional light-to-heat conversion ability. We further demonstrate the close correlation of the Jo number of Au NPs of different shapes with their optical absorption power density.

Unravelling crystal growth of nanoparticles.

Crystal growth from nanoscale constituents is a ubiquitous phenomenon in biology, geology and materials science. Numerous studies have focused on understanding the onset of nucleation and on producing high-quality crystals by empirically sampling constituents with different attributes and varying the growth conditions. However, the kinetics of post-nucleation growth processes, an important determinant of crystal morphology and properties, have remained underexplored due to experimental challenges associated with real-space imaging at the nanoscale. Here we report the imaging of the crystal growth of nanoparticles of different shapes using liquid-phase transmission electron microscopy, resolving both lateral and perpendicular growth of crystal layers by tracking individual nanoparticles. We observe that these nanoscale systems exhibit layer-by-layer growth, typical of atomic crystallization, as well as rough growth prevalent in colloidal systems. Surprisingly, the lateral and perpendicular growth modes can be independently controlled, resulting in two mixed crystallization modes that, until now, have received only scant attention. Combining analytical considerations with molecular dynamics and kinetic Monte Carlo simulations, we develop a comprehensive framework for our observations, which are fundamentally determined by the size and shape of the building blocks. These insights unify the understanding of crystal growth across four orders of magnitude in particle size and suggest novel pathways to crystal engineering.

Solvent-Dispersible Nanostructured MIMI: An Experimental and Computational Study

A MIMI (metal–insulator-metal–insulator) nanoparticle was conceived and synthesized. It consists of a core of gold nanoparticles of different shapes, covered by a silica shell in turn covered by a layer of gold and finally by another silica shell. This hybrid nano-matryoshka, completely dispersed in water, was characterized by UV–Vis and TEM spectroscopy, comparing the architecture and photophysical properties of each synthetic step. Through a numerical simulation, it was possible to study in depth the absorption and extinction cross sections, determining the role of the various layers. This is an example of architecture used in the construction of metamaterials, the first in the form of a water-dispersed nanoparticles.

Effective role of mineral oil and biological nanomaterial on thermal energy influenced by magnetic dipole and nanoparticle shape

This study of synovial fluid was conducted by considering two different nanofluid models over a two-dimensional stretched surface using nanoparticles of different shapes. We obtained remarkable results regarding the impact of nanoparticles on thermal performance. Through this study, we assessed heat and mass transfer and the involvement of magnetic dipole of chemically reactive species in two-dimensional steady incompressible flow. Heat generation was incorporated in the energy equation and a first-order chemical reaction was involved in the mass transport phenomenon. The concept of boundary layer was adopted to derive the physical problem in Cartesian coordinates, with results in the form of coupled partial differential equations (PDEs). The derived PDEs were highly non-linear, and exact solutions were not possible. Therefore, the PDEs were converted into non-linear ordinary differential equations (ODEs) using appropriate similarity transformation and then solved numerically via the finite element method. The impact of numerous emerging parameters on the solutions are displayed graphically, and the physical significance is discussed. An increment in Sc,Kc, and γ decelerated the solute field, while the concentration gradient increased with enhancement in Sc. Maximum acceleration in velocity for model-I was produced compared to acceleration in the velocity field for model-II.

Polymeric Nanoparticles as a Self‐Adjuvanting Peptide Vaccine Delivery System: The Role of Shape

AbstractAntigens incorporated in subunit vaccines are typically poorly immunogenic, so a strong immunostimulant (adjuvant) and/or delivery system is required to boost immunogenicity. In this work, the various functional polymer nanostructures, that is, rods, worms, spheres, and tadpoles are used to develop potent peptide antigen delivery systems. The antigen PADRE‐J8 (PJ8), derived from Group A Streptococcus (GAS) M‐protein, is either physically mixed or chemically conjugated to polymeric nanoparticles of different shapes. The physical mixture of polymeric nanoparticles and antigen is more effective in inducing antibody production than their chemical conjugates. Moreover, rod‐shaped polymeric nanoparticles in physical mixture with PJ8 elicited higher and more opsonic antibody titers than powerful complete Freund's adjuvant (CFA)‐adjuvanted antigen. Herein, for the first time it is demonstrated that a) the block copolymer, in nanoparticle form, can act as an immune adjuvant, b) nanoparticle shape plays a crucial role in their immunogenicity, and c) antigen conjugation is not required, nor is antigen encapsulation or absorption.

Gold nanorods derivatized with CTAB and hydroquinone or ascorbic acid: spectroscopic investigation of anisotropic nanoparticles of different shapes and sizes.

Gold nanorods stabilized by binary ligand mixtures of cetyltrimethylammonium bromide (CTAB, primary ligand) and ascorbic acid or hydroquinone were investigated by complementary synchrotron radiation-induced spectroscopies and microscopies, with the aim to find evidence of the influence of the secondary ligand molecular and chemical structure on the nanorod shapes and size ratios. Indeed, as it is well known that the CTAB interaction with Ag(i) ions at the NR surface plays a key role in directing the anisotropic growth of nanorods, the possibility to finely control the NR shape and dimension by opportunely selecting the secondary ligands opens new perspectives in the design and synthesis of anisotropic nanoparticles.