Properties Of Micro Research Articles

A comprehensive study of the antibacterial and shielding properties of micro and nano-EPVC lead-free shields

Lead-composites products are usable materials for the personal protection of the patient from x-ray during radiation operations. Nevertheless, lead has high toxicity and environmental disadvantages. This research aims at the preparation of flexible, lead-free, and antibacterial composites for protection against x-ray radiation. At first, nanoparticles of molybdenum trioxide (MoO3), copper oxide (CuO), and tin (IV) oxide (SnO2) were synthesized with hydrothermal and sol-gel methods. Six types of composites containing the 50% Wt of various mixtures of nano and micro particles of MoO3, CuO, and SnO2 in the emulsion of polyvinylchloride were prepared. Then, the morphological characteristics and size distribution of the samples were determined by the dynamic light scattering (DLS) analysis, and the bond between the matrix and the filler was investigated by Fourier Transform Infrared Spectroscopy (FTIR). Also, the antibacterial effect of the composites and X-ray diffraction (XRD) of nanoparticles were studied. Furthermore, the x-ray attenuation coefficient was measured in 40, 80, and 120 kVp. Indeed, the mass attenuation coefficients and 0.25 mm lead equivalent thickness were calculated for all samples. The results indicated that the nanocomposites show better attenuation than the other composites in all the energies. The composites containing MoO3 and CuO also proved to have better mass attenuation coefficients than the others. Considering the equivalent thickness for 0.25 mm of lead in high and low energy, the composites containing all the three metal oxides can be considered suitable for attenuation. Also, the composites containing CuO can provide antibacterial properties.

Investigations on Mechanical Properties of Micro- and Nano-Particulates (Al2 O3/B4C) Reinforced in Al 7075 Matrix Composite

Investigations on Mechanical Properties of Micro- and Nano-Particulates (Al2 O3/B4C) Reinforced in Al 7075 Matrix Composite

Micro and Nano of ZnO Particles Effect on Some Mechanical and Thermal Properties of Epoxy Resin Composites

Effect of Micro and Nano particle of Zinc Oxide on the mechanical and thermal conductivity properties of an epoxy micro and nanocomposite were studied. Micro and nanocomposites were prepared using Open template method and by different weight ratios of micro and nano of ZnO particles having an average size of (45 µm) and (50 nm), respectively. The mechanical properties of micro and nano-composites were studied using Mechanical measuring devices including tensile strength devices, Shock resistance and Shore hardness Effects of ZnO micro and nanoparticles on the curing behavior of these micro and nanocomposites were investigated utilizing lee disc method. It was found that, ZnO micro and nanoparticles can effectively influence on the mechanical and thermal properties of epoxy coating. In addition, as the results showed an improvement in the mechanical properties of the epoxy compound supported with nanoparticles better than the compound supported with micro-particles, The values of hardness (81,82,82.4, and 83 N/mm2 ) for the microcomposites and (81.2,82.8,83, and 84 N/mm2) for the nanocomposites compared its value (79) for pure epoxy and the impact values (17.5,18.75,21.25, and 26.25kJ/m2) for the microcomposites and (18,21.25,23.75, and 27.5kJ/m2) for the nanocomposites compared its value (16.25) for pure epoxy and for the ratios (0.1,0.3,0.5, and 0.7 wt%) respectively , while the results showed a decrease in the thermal conductivity of the epoxy compound supported by micro and nanoparticles with an increase in the weight ratios. Micro and Nano particle of ZnO

On Micro-generalized Closed Sets and Micro-generalized Continuity in Micro Topological Spaces

The purpose of this paper is to define and study a new class of sets called micro generalized closed sets and define micro generalized continuous function and irresolute micro generalized continuous function in micro topological spaces. Basic properties of micro generalized closed sets and its characterizations are analyzed.

Study on the Thermal and Impact Resistance Properties of Micro PA66/PU Synergistically Reinforced Multi-Layered Biaxial Weft Knitted Fabric Composites

Abstract In this paper, the influence of micro PA66/PU in multi-layered biaxial weft knitted (MBWK) fabric reinforced composites on thermal and impact resistance was studied. The main objective was to investigate the role of micro PA66/PU in terms of improving material performance. The results showed that the addition of micro PA66/PU improved the thermal stability of the MBWK composite. It is observed that the onset degradation temperatures increased by 1.6°C in thermo-gravimetric analysis (TGA) test and the Tg increased by 2.8°C in the dynamic mechanical analysis (DMA) test. Besides, the impact energy absorption of composites increased by 5.3% after the addition of micro PA66/PU. The addition of micro PA66/PU effectively reduced the impact damage area from the failure morphology after impact. In simple words, the addition of micro PA66/PU effectively improves the comprehensive properties of composites.

Investigating The Permeability Prediction Using Geometric Properties of Micro Computed Tomography Images by Linear Regression Models

Challenges on rock absolute permeability prediction from tiny sample when laboratory apparatus is not applicable and without pore network modelling is remarkable. This prediction using the characterization of micro-computed tomography images have been studied in this paper. Twenty series of 2D micro computed tomography rock binary images have been collected, each of them was considered as a 3D binary image. Their geometric measures in 2D and 3D for measuring image properties have been considered using Minkowski functionals and available functions, developing a regression model, absolute permeabilities have been evaluated. Some 2D and 3D geometric properties are considered. The area, the perimeter and the 2D Euler number are 2D binary images properties. The volume, the surface area, the mean breadth also known as integral of the mean curvature, and the 3D Euler Number are 3D binary images properties. Porosity and number of objects also have been considered as parameters of a regression model.To perform linear regression, twenty-four parameters were evaluated and some of them were chosen to be used. An equation is proposed based on the extensive study conducted which can predict rock permeability. This equation has two sets of parameter coefficients, one set predicts high permeability rocks (above two Darcy) and the other for low and medium permeability (less than two Darcy) which can be used for carbonated rock. Average absolute relative error for conducted cases is 0.06.

Enhancing Anticorrosion Properties of Micro–Nano Zinc Vanadate from Atomic Modulation Supplemented by Light Modification

Enhancing Anticorrosion Properties of Micro–Nano Zinc Vanadate from Atomic Modulation Supplemented by Light Modification

Functional Micro-/Nanomaterials for Multiplexed Biodetection.

When analyzing biological phenomena and processes, multiplexed biodetection has many advantages over single-factor biodetection and is highly relevant to both human health issues and advancements in the life sciences. However, many key problems with current multiplexed biodetection strategies remain unresolved. Herein, the main issues are analyzed and summarized: 1)generating sufficient signal to label targets, 2) improving the signal-to-noise ratio to ensure total detection sensitivity, and 3) simplifying the detection process to reduce the time and labor costs of multiple target detection. Then, available solutions made possible by designing and controlling the properties of micro- and nanomaterials are introduced. The aim is to emphasize the role that micro-/nanomaterials can play in the improvement of multiplexed biodetection strategies. Through analyzing existing problems, introducing state-of-the-art developments regarding relevant materials, and discussing future directions of the field, it is hopeful to help promote necessary developments in multiplexed biodetection and associated scientific research.

The effect of thermomechanical process on metallurgical and mechanical properties of 38MnVS6 micro alloyed steel

AbstractThis study aims to have the proper mechanical properties without applying any heat treatment process after hot forging by using 38MnVS6 micro alloyed steel in tow hook manufacturing which is used in automobiles. The effect of forging temperature and cooling rate on metallurgical and mechanical properties of micro alloyed steel is investigated. The samples of micro alloyed steel are forged at 800 °C, 850 °C, 900 °C, 1050 °C and cooled down at the rates of 0.75 °C/s and 1.5 °C/s. The forging temperature and the cooling rate have a significant effect on toughness by the experimental and numerical studies. The amount of ferrite increases with a decreasing forging temperature, and the toughness is improved by increasing the amount of ferrite. Also, by increasing the cooling rate after forging at 1050 °C, the acicular ferrite is observed which has a positive effect on both the toughness and strength of the micro alloyed steel.

High mechanical properties of micro fibrillated cellulose/HDPE composites prepared with two different methods

Compared to materials fabricated by traditional polymer, cellulose was chosen to improve the strength of composites due to its excellent performance in mechanical and thermal expansion properties. However, in the current investigation of manufacturing cellulose nanofibril (CNF)/high-density polyethylene (HDPE) composites, the instinct of CNF tends to aggregate, limiting the content of CNFs in composites (mostly no more than 10 wt%). Herein, we reported two green and continuous manufacturing methods, naming “suspension blending method” and “dry blending method”. Micro fibrillated cellulose (MFC) was selected to enhance the stability of interfaces between HDPE with the synergetic interaction of cationic polyacrylamide, resulting in the flexural strength of ~ 78.87 MPa and the flexural modulus of ~ 3.45 GPa, which are ~ 190.12% and ~ 315.66% higher than pure HDPE respectively. Besides, the thermal expansion coefficient of our samples is ~ 28.9 ppm/k, ~ 80.3% lower than those made by HDPE. The prepared MFC/HDPE composites are expected to pave the way for the development in auto manufacturing and engineering.

Nafion Thin Films: Fabrication of Micro‐ and Nanopatterned Nafion Thin Films with Tunable Mechanical and Electrical Properties Using Thermal Evaporation‐Induced Capillary Force Lithography (Adv. Mater. Interfaces 7/2021)

In article number 2002005, Hyung Jin Kim, Deok-Ho Kim, and co-workers describe a facile method for enhancing the pattern fidelity of Nafion thin films that utilizes a thermal evaporation-induced capillary force lithography with a swelling process. Mechanical and electrical properties of micro- and nano-patterned Nafion films can be controlled by adjusting curing temperature and Nafion concentration.

Three-dimensional nanoprinting via charged aerosol jets.

Three-dimensional (3D) printing1-9 has revolutionized manufacturing processes for electronics10-12, optics13-15, energy16,17, robotics18, bioengineering19-21 and sensing22. Downscaling 3D printing23 will enable applications that take advantage of the properties of micro- and nanostructures24,25. However, existing techniques for 3D nanoprinting of metals require a polymer-metal mixture, metallic salts or rheological inks, limiting the choice of material and the purity of the resulting structures. Aerosol lithography has previously been used to assemble arrays of high-purity 3D metal nanostructures on a prepatterned substrate26,27, but in limited geometries26-30. Here we introduce a technique for direct 3D printing of arrays of metal nanostructures with flexible geometry and feature sizes down to hundreds of nanometres, using various materials. The printing process occurs in a dry atmosphere, without the need for polymers or inks. Instead, ions and charged aerosol particles are directed onto a dielectric mask containing an array of holes that floats over a biased silicon substrate. The ions accumulate around each hole, generating electrostatic lenses that focus the charged aerosol particles into nanoscale jets. These jets are guided by converged electric-field lines that form under the hole-containing mask, which acts similarly to the nozzle of a conventional 3D printer, enabling 3D printing of aerosol particles onto the silicon substrate. By moving the substrate during printing, we successfully print various 3D structures, including helices, overhanging nanopillars, rings and letters. In addition, to demonstrate the potential applications of our technique, we printed an array of vertical split-ring resonator structures. In combination with other 3D-printing methods, we expect our 3D-nanoprinting technique to enable substantial advances in nanofabrication.

A review on tribo-mechanical properties of micro- and nanoparticulate-filled nylon composites

Abstract Nylon composites are of evolving interest due to their good strength, toughness, and low coefficient of friction. Various fillers like micro- and nanoparticulates of metals and metal compounds were used to enhance the mechanical and tribological properties of nylons for many years by researchers. In this paper, an overall understanding of composites, filler materials, especially particulate filler materials, application areas of polymer composites, wear of polymers, and the effect of various fillers on tribo-mechanical properties of nylons have been discussed. The detailed review is limited to micro- and nanoparticulate fillers and their influence on the mechanical and tribological properties of various nylon matrices.

Effect of TaC microparticles on structure and properties of micro- arc oxidation coating on Ti-6Al-4V alloy

Effect of TaC microparticles on structure and properties of micro- arc oxidation coating on Ti-6Al-4V alloy

Multiorder Nonlinear Mixing in Metal Oxide Nanoparticles.

Whereas most of the reports on the nonlinear properties of micro- and nanostructures address the generation of distinct signals, such as second or third harmonic, here we demonstrate that the novel generation of dual output lasers recently developed for microscopy can readily increase the accessible parameter space and enable the simultaneous excitation and detection of multiple emission orders such as several harmonics and signals stemming from various sum and difference frequency mixing processes. This rich response, which in our case features 10 distinct emissions and encompasses the whole spectral range from the deep ultraviolet to the short-wave infrared region, is demonstrated using various nonlinear oxide nanomaterials while being characterized and simulated temporally and spectrally. Notably, we show that the response is conserved when the particles are embedded in biological media opening the way to novel biolabeling and phototriggering strategies.

Charge-Based Separation of Micro- and Nanoparticles.

Deterministic Lateral Displacement (DLD) is a label-free particle sorting method that separates by size continuously and with high resolution. By combining DLD with electric fields (eDLD), we show separation of a variety of nano and micro-sized particles primarily by their zeta potential. Zeta potential is an indicator of electrokinetic charge—the charge corresponding to the electric field at the shear plane—an important property of micro- and nanoparticles in colloidal or separation science. We also demonstrate proof of principle of separation of nanoscale liposomes of different lipid compositions, with strong relevance for biomedicine. We perform careful characterization of relevant experimental conditions necessary to obtain adequate sorting of different particle types. By choosing a combination of frequency and amplitude, sorting can be made sensitive to the particle subgroup of interest. The enhanced displacement effect due to electrokinetics is found to be significant at low frequency and for particles with high zeta potential. The effect appears to scale with the square of the voltage, suggesting that it is associated with either non-linear electrokinetics or dielectrophoresis (DEP). However, since we observe large changes in separation behavior over the frequency range at which DEP forces are expected to remain constant, DEP can be ruled out.

Preparation and properties of micro- and nanocomposites composed of a water-soluble nylon and aramid fibers

A commercial 20 wt% solid paste of microfibrillated aramid fibers (MFAs) containing water was treated with potassium hydroxide in dimethyl sulfoxide to produce aramid nanofibers (ANFs). Nanocomposites composed of a water-soluble nylon (A-90, amine-modified poly(ɛ-caprolactam)) and ANFs with fiber contents of 0–5 phr (i.e., parts per hundred resin) were prepared by a casting method of the resin/fiber dispersion in water. A-90/MFA microcomposites were also prepared by the same method for comparison. The FE-SEM analysis revealed that ANFs are much finer than MFAs, and both the fibers are homogeneously dispersed in all the composites. The glass transition and maximum thermal decomposition temperatures of A-90/ANF and A-90/MFA composites were higher than those of A-90. The tensile strength, tensile modulus and elongation at break for A-90/ANF and A-90/MFA composites increased with increasing fiber content. When tensile properties of A-90/ANF and A-90/MFA composites with the same fiber content were compared, A-90/ANF nanocomposites exhibited much better tensile properties than A-90/MFA composites did. Especially, the tensile toughness of A-90/ANF 5 phr was about three times higher than that of A-90.

Green Synthesis up to Geometric Gold Microparticles

In this work the study of optical properties of micro and nanostructured particles of gold is approached. A method of nanoparticle stabilization synthesis based on the philosophy of green chemistry by using orange extract (Citrus X sinensis) was proposed. Controlling specific parameters of the proposed synthesis method, particles with sizes lower than 50 nm were obtained and after the heat treatment the geometric particle sizes ranged from 0.2 to 2 μm. The optical absorption of the particles was studied finding absorption bands associated with the surface plasmon resonance. Experimentally, the nanomaterials obtained were tested on pyridine as SERS substrate. Complementary, in order to find clues of vibrational behavior, theoretically the interaction with pyridine molecule and gold layer structure were considered. The individual systems were perturbed by incident radiation with blue (435 nm), green (532 nm), red (638 nm) and infrared (785 nm and 1064) wavelengths for its SERS analysis.

The effect of graphene nanoplatelets on technical properties of micro- and nano-sized TiO2 matrix: a comparative research study on electrical and optical characteristics

In this study, titanium dioxide (TiO2)-based graphene nanoplatelets (GNPs)-reinforced composite materials were produced and the electrical and optical properties of the composite materials were investigated. Graphene, which was used as a reinforcing material, was produced by using liquid-phase exfoliation method. While the TiO2 used as matrix material was commercially available for the first group of samples, it was produced by using the sol–gel method for the second group of the samples. Different rates of graphene were added to the TiO2 powders which were commercially available and produced by using sol–gel method. GNPs used as a reinforcing material were subjected to TEM analysis. The resulting composite materials were structurally examined in SEM and XRD. Then, the changes in electrical conductivity of these composites under the impact of temperature were measured. UV–Vis spectrometers of the samples were taken and their optical properties were determined. When temperature-based electrical examination of the produced composite materials was performed, an increase was observed on the electrical conductivity values in both groups of samples as a result of addition of the reinforcing element. In addition, TiO2-containing composites produced by using sol–gel method had lower electrical conductivity comparing with commercially purchased TiO2-containing composites especially at high temperatures. In the optical measurements, it was observed that there was an increase in the optical bandgap energy range values with GNPs reinforcement but a decrease in the reflectance values.

Study the hydro and thermal performance of microchannel heat exchanger with hybrid suspension of nanoparticles and MEPCM particles

This paper aims to study the flow and heat transfer of hybrid suspension in counter flow micro channel heat exchanger (CFMCHE). In order to enhance the thermal properties of micro encapsulated phase change material (MEPCM) suspension. The hybrid suspension studied in this paper consists of nanoparticles and MEPCM particles, these particles are suspended in water as abase fluid, two types of hybrid suspension are used (Cu + MEPCM suspension) and (Al2O3+ MEPCM suspension) by n-octadecane as a PCM for both of them. The hydrodynamic and thermal characteristics of thes suspensions flow in micro channels of CFMCHE is numerically investigated. From obtained results, using of hybrid suspensions as a cooling fluid lead to modify thermal performance of a CFMCHE by increase its effectiveness but it also lead to high increasing in pressure drop. The results showed considerable enhancement in cooling effectiveness of (Al2O3 + MEPCM suspension) above of the pure PCM suspension, Nanofluids, and water. While (Cu + MEPCM suspension) showed enhancement above of the pure PCM suspension and water, but was not best effectiveness than Nanofluids. Extra increase in pressure drop in both types of hybrid suspension above are leads to reduce the overall performance compared with pure PCM suspension. Therefore its use depends on the application at which this heat exchanger is employed