Dual Particle Size Research Articles

ЗАВИСИМОСТЬ ДЗЕТА-ПОТЕНЦИАЛА ПЛЕНКООБРАЗОВАТЕЛЯ НА ОСНОВЕ НЕОТВЕРЖДЕННОГО КАЛИЙ-НАТРИЕВОГО ЖИДКОГО СТЕКЛА ОТ КОНЦЕНТРАЦИИ ЕГО СОСТАВЛЯЮЩИХ

One of the important tasks of modern production is the development of such finishing protective and decorative coatings that do not adversely affect the environmental situation. In this connection, the market reorientation from organically dilutable paint and varnish materials to water-based paint and varnish materials is becoming more and more obvious. Such paint and varnish materials for protective and decorative purposes include paints produced on the basis of liquid glass. On the basis of liquid glass are produced silicate facade paints with improved performance and fire protection properties, which are resistant to ultraviolet radiation and sharp temperature changes, they are more durable, environmentally friendly, they have a lower cost compared to acrylic, polyvinyl acetate, water dispersion paintwork materials. At present in scientific and technical literature there are numerous publications devoted to silicate coatings on concrete, ceramic surfaces, paving slabs, slate. However, despite the large number of patented formulations, there are no publications on the coating composition-colloidal properties relationship in the periodic literature. In the present study, the zeta potential of film formers based on potassium liquid glass and latex, potassium-sodium liquid glass and latex was determined to determine the stability of uncured solutions. The studies were carried out using a dual angle particle size analyser Zetasizer Nano ZS, Malvern. The measurements were performed in a U-shaped cuvette with gold electrodes at pH = 7.4 and temperature 25oC. As a result of experiments it was found that the most stable are uncured film formers based on potassium liquid glass and latex with the addition of sodium liquid glass. The developed recommendations will allow manufacturers of silicate paints to improve their quality with simultaneous reduction of production cost.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 33.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 33.

Conjugated dual size effect of core-shell particles synergizes bimetallic catalysis

Core-shell bimetallic nanocatalysts have attracted long-standing attention in heterogeneous catalysis. Tailoring both the core size and shell thickness to the dedicated geometrical and electronic properties for high catalytic reactivity is important but challenging. Here, taking Au@Pd core-shell catalysts as an example, we disclose by theory that a large size of Au core with a two monolayer of Pd shell is vital to eliminate undesired lattice contractions and ligand destabilizations for optimum benzyl alcohol adsorption. A set of Au@Pd/SiO2 catalysts with various core sizes and shell thicknesses are precisely fabricated. In the benzyl alcohol oxidation reaction, we find that the activity increases monotonically with the core size but varies nonmontonically with the shell thickness, where a record-high activity is achieved on a Au@Pd catalyst with a large core size of 6.8 nm and a shell thickness of ~2–3 monolayers. These findings highlight the conjugated dual particle size effect in bimetallic catalysis.

Influence of Dual Range Particle Size on Wear and Friction Properties of Ilmenite Reinforced Aluminium Metal Matrix Composite

Influence of Dual Range Particle Size on Wear and Friction Properties of Ilmenite Reinforced Aluminium Metal Matrix Composite

Impact of Mono- and Dual-Sized α-Fe2O3 Catalyst Mixtures on the Thermochemical Processing of Pinewood for Upgraded Liquid Chemicals

The incorporation of mono-sized particle catalysts in real industrial systems for biomass conversion is a significant challenge, hence the impact of individual α-Fe2O3 catalysts with varying non-ideal spherical sizes of 54 nm (FS054), 221 nm (FS221), and ∼2 µm (FSm002) as well as dual-sized mixtures (FS054-FS221 and FS221-FSm002) were considered in the catalytic upgrading of pinewood pyrolysis vapors. The size variation of the α-Fe2O3 catalyst revealed a substantial effect on the product distribution. Although the yield of phenols shows a decrease by almost a factor of two irrespective of the catalyst particle size, the FS221 catalyst demonstrates the most potent effect on reducing phenols through decarboxylation reactions. Considering the role of the catalyst on the individual phenolics, the FS221 catalyst reveals higher selectivity towards the reduction of 2-methoxyphenol, isoeugenol, and eugenol, whereas the application of FS054 catalysts displays a stronger impact on the decrease of creosol and other phenols. Both FS054 and FS221 catalysts showed the highest effectiveness in reducing the relative yield of 2-methoxy-4-vinylphenol. Applying a dual-size mixture (FS054-FS221) shows a synergetic effect, simultaneously decreasing the content of phenols, acids, and aldehydes followed by a strong CO2 release attributed to competitive decarbonylation reactions of aldehydes. The appearance of γ-Fe2O3 small fraction was revealed in the powders with mono-(FS221) and dual particle size (FS054-FS221 and FS221-FSm002), whereas the FS054 and FSm002 catalysts demonstrate good chemical and phase stability.

Dual targeting powder formulation of antiviral agent for customizable nasal and lung deposition profile through single intranasal administration

Unpredictable outbreaks due to respiratory viral infections emphasize the need for new drug delivery strategies to the entire respiratory tract. As viral attack is not limited to a specific anatomic region, antiviral therapy that targets both the upper and lower respiratory tract would be most effective. This study aimed to formulate tamibarotene, a retinoid derivative previously reported to display broad-spectrum antiviral activity against influenza and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), as a novel dual particle size powder formulation that targets both the nasal cavity and the lung by a single route of intranasal administration. Spray freeze drying (SFD) and spray drying (SD) techniques were employed to prepare tamibarotene powder formulations, and cyclodextrin was used as the sole excipient to enhance drug solubility. With the employment of appropriate atomizing nozzles, particles of size above 10 μm and below 5 μm could be produced for nasal and lung deposition, respectively. The aerosol performance of the powder was evaluated using Next Generation Impactor (NGI) coupled with a glass expansion chamber and the powder was dispersed with a nasal powder device. By blending powder of two different particle sizes, a single powder formulation with dual aerosol deposition characteristic in both the nasal and pulmonary regions was produced. The aerosol deposition fractions in the nasal cavity and pulmonary region could be modulated by varying the powder mixing ratio. All dry powder formulations exhibited spherical structures, amorphous characteristics and improved dissolution profile as compared to the unformulated tamibarotene. Overall, a novel dual targeting powder formulation of tamibarotene exhibiting customizable aerosol deposition profile was developed. This exceptional formulation strategy can be adopted to deliver other antimicrobial agents to the upper and lower airways for the prevention and treatment of human respiratory infections.

Effect of Dual Particle Size Corundum Particles on the Tribological Properties of LM30 Aluminium Alloy Composites for Brake Rotor Applications

Effect of Dual Particle Size Corundum Particles on the Tribological Properties of LM30 Aluminium Alloy Composites for Brake Rotor Applications

Free Vibration Analysis of A357 Alloy Reinforced with Dual Particle Size Silicon Carbide Metal Matrix Composite Plates Using Finite Element Method

In this work, the free vibration behaviour of A357 composite plate reinforced with dual particle size (DPS) (3 wt. coarse + 3 wt. fine, 4 wt. coarse + 2 wt. fine, and 2 wt. coarse + 4 wt. fine) SiC is evaluated using the finite element method. To this end, first-order shear deformation theory (FSDT) has been used. The equations of motion have been derived using Hamilton's principle and the solution has been obtained through condensation technique. A thorough parametric study was conducted to understand the effect of reinforcement size and weight fraction, boundary conditions, aspect ratio and length-to-width ratio of plate geometry on natural frequencies of A357/DPS-SiC composite plates. Results reveal significant influence of all the above variables on natural frequency of the composite plates. In all the cases, A357 composite plate reinforced with 4 wt. coarse and 2 wt. fine SiC particles displayed the highest natural frequency owing to its higher elastic and rigidity modulus. Further, the natural frequencies increase with decrease in aspect ratio of the plate geometry. Natural frequency also decreases with increase in the number of free edges. Lastly, increasing the length-to-width ratio drastically improves the natural frequency of the plates. © 2021 Polish Academy of Sciences. All rights reserved.

Influence of two different range of sillimanite particle reinforcement on tribological characteristics of LM30 based composites under elevated temperature conditions

In this work, high temperature wear-resistant LM30/sillimanite composites for automotive applications have been fabricated. Dual particle size composites reinforced with naturally occurring sillimanite mineral were processed and investigated for operating temperatures in the range of 50–300 °C. Sillimanite particles with size range of 1–20 μm (fine) and 75–106 μm (coarse) were mixed in weight ratio of 3:1, 1:1, and 1:3 to be reinforced to the LM30 alloy. SEM micrographs and area mapping/line mapping profile results showed presence of different phases and revealed that sillimanite inclusion changed the morphology of proeutectic silicon to globular and refined its grain size. Particles were well distributed in LM30 matrix. Increase in reinforcement level of particles led to continuous improvement in properties. As such, the best properties were obtained in composite containing 15 wt% sillimanite with proportion of fine: coarse particles as 3:1 (15-DPS3 composite). The transition temperature of wear mode increased from 150 °C for base alloy to 200 °C for composites. For the temperature-pressure condition of 200–1 MPa, 15-DPS3 composite showed 15% higher hardness, 80% lower wear rate, 48% lower friction coefficient, and 28% lower thermal expansion coefficient than base alloy. These wear characteristics of composites were comparable to the commercially used grey cast iron material. XRD of wear track/debris confirmed the formation of tribolayer. SEM analysis of wear track/debris identified the wear mechanisms causing materials loss under different contact pressures. Light-weight and economical composites developed in this research can act as a good substitute for the heavy cast iron components used in industry.

The effect of heat treatment on the mechanical and tribological properties of dual size SiC reinforced A357 matrix composites

In the present work, the effect of aging temperature and particle size ratio of SiC particles on the mechanical and tribological properties of A357 composites reinforced with dual particle size SiC were investigated. The composites were prepared by melt-stirring assisted permanent mold casting technique with different weight fractions (3% coarse +3% fine, 4% coarse +2% fine, and 2% coarse +4% fine) of large and small size SiC particles. These three prepared composites are referred as DPS1, DPS2 and DPS3 composites. The solutionizing temperature was maintained constant at 540°C for 9h while the aging was done at 160°C, 180°C and 200°C (T6 treatment) for 6h. Optical and scanning electron microscopy studies showed fairly uniform dispersion of dual size SiC particles in A357 matrix with good interfacial bonding. High-resolution transmission electron microscopy images showed formation of uniformly dispersed needle-like β″ phase and spherical shaped β-Mg2Si precipitates under peak aging conditions. Compared to T6 treated A357 alloy, the T6 treated DPS A357 composites showed improved yield strength, tensile strength, hardness and wear resistance. Among the three composites, hardness and wear resistance of T6 treated DPS2 composite was found to be significantly higher when compared to the other two composites (DPS1 and DPS3). Ratio of large particles to small particles also seems to effect the mechanical and tribological properties. Presence of more small particles was found to be good for strength and ductility whereas more large particles were found to be good for hardness and wear resistance.

On wear of 3D printed Al2O3 reinforced Nylon6 matrix based functional prototypes

The use of fused deposition modelling (FDM) based functional prototypes for wear resistance applications is presently limited mainly because of selective material availability of filament materials. Various research groups have reinforced several fillers in thermoplastic base to prepare feedstock filaments to improve the mechanical properties and to address the reusability issue of polymeric waste. But hitherto the effect of Al2O3 particle sizes (as single, dual and triple particle size as reinforcement) in Nylon6 thermoplastic blend has been less explored. In the present investigation an effort has been made to prepare feed stock filament for 3D printing application to explore its wear resistant properties. The current investigation suggested that dual particle size reinforced pin exhibit better wear properties followed by triple and single particle reinforced pins. The wear tracks obtained in this study shows that dual particle size based composite material is highly wear resistant as compared to virgin acrylonitrile butadiene styrene (ABS)/ Nylon6. The results have been supported by scanning electron microscopy (SEM) images of prepared pins for wear testing.

Multifactor optimization for development of hybrid aluminium matrix composites

The present study aims to multi factor optimization for preparation of aluminum matrix composites (AMC) by reinforcement of SiC/ Al2O3/ Al2O3+ SiC particles having dual particle size (DPS) and triplicate particle size (TPS) based upon signal to noise (S/N) ratio analysis. In this work the amalgamation of fused deposition modelling (FDM) and vacuum moulding (V-process) assisted stir casting (SC) has been employed for the development of AMC. The process parameters under investigation are: particle size (DPS/ TPS); reinforcement type (Al2O3/ SiC/ Al2O3+ SiC); vacuum pressure (VP) (300-400 mm of Hg); moulding sand grit size (American foundry society (AFS) No. 50-70); vibration time (VT) (4-6 sec) and reinforcement proportion/composition (5/7.5/10 by wt.%). The S/N ratio based upon the wear performance (pin-on disc tester), micro hardness (HV) and dimensional accuracy/deviation (Δt) has been evaluated by using Minitab-17 software which further acts as input for multifactor optimization. The best parametric setting proposed for multi objective/factor optimization is: DPS of Al2O3+ SiC reinforcement at 350 mm of Hg VP with 50 AFS No. sand grain size, 4sec VT and 10% composition/proportion. The results of analysis of variance (ANOVA) highlight that particle size (with 18.49% contribution) and reinforcement type (with 42.13% contribution) have significant influence on multi factor optimization for the development of AMC. Confirmatory experiments have been performed which shows that the proposed amalgamation of FDM and V-process assisted SC can be successfully applied for enhancing the performance of AMC. Finally the X-chart and R-chart have been plotted at the proposed settings, which highlights that amalgamation process is controlled and useful for mass/ batch production.

On SiC/Al2O3 reinforced HDPE 3D printed rapid tooling

This work reports the in-house fabrication of SiC/Al2O3 reinforced rapid tooling (RT) using feed stock filament prepared by single screw extrusion for fused deposition modelling (FDM) platform. The current investigation focuses on preparation of high density polyethylene (HDPE) matrix reinforced with single particle size, dual particle size and triple particle size for RT applications. The study suggests that triple particle size of Al2O3 is best alternative among single, double and triple particle size of reinforcement for preparation of RT. Also the study highlights that the infill density (ID) plays significant and most important input processing parameter for preparation of RT comprising of HDPE composite matrix from dimensional accuracy and hardness view point. The differential scanning calorimetry (DSC) study suggested us that the RT prepared with HDPE composite matrix is thermally stable.

Microstructure, mechanical and wear properties of the A357 composites reinforced with dual sized SiC particles

Current work reports on the development of A357 alloy composite which is reinforced with dual size SiC particles by stir casting route. Influence of different weight fractions (3% coarse+ 3% fine, 4% coarse + 2% fine, and 2% coarse + 4% fine) of dual size SiC particles on mechanical properties and wear resistance of A357 composites is the focus of this work. Hardness and tensile properties were studied for dual size composites and then were compared with A357 alloy. Microstructural study, fractured surface and worn surface investigation were carried out using optical and scanning electron microscopes respectively. Microstructural analysis showed fairly uniform dispersion of dual size SiC particles in A357 matrix with good interfacial bonding. Compared to A357 alloy, the composites showed improvement in hardness, yield, and tensile strength. In particular, composite with 4 wt. % of fine and 2 wt. % of large SiC particles displayed the highest tensile strength while composite with 4 wt. % of large and 2 wt. % of fine SiC particles exhibited high hardness and wear resistance among A357 alloy and dual particle size composites. The strengthening mechanisms that contributed to improvement in strength values were effective load transfer and dislocation strengthening due to thermal mismatch.

Investigations for Surface Hardness of Aluminum Matrix Composites with Hybrid Reinforcement

This work focuses on the investigations of hybrid reinforcement of SiC/Al2O3 as dual particle size and triple particle size (TPS) on the surface hardness of hybrid aluminum matrix composite (AMC) prepared with synergistic combination of fused deposition modeling, vacuum molding (V) process and stir casting. It was observed that TPS-based SiC resulted into highest microhardness of 45HV. Further, ANOVA revealed that the percentage contribution of particle size and type of reinforcement on surface hardness of AMC were 27.30% and 48.72%, respectively. The best parametric setting (of input parameters) for microhardness is: particle size—TPS, type of reinforcement—SiC, vacuum pressure—350 mm of Hg, sand grain size—70 (AFS no.), vibration time—4 s. and composition/proportion of reinforcement in Al matrix—10%, respectively, and overall, 5.1% improvement in microhardness was observed at proposed parametric setting. The presence of Al2O3/SiC responsible for the improvement in microhardness was supported by photomicrographs.

Effect of dual particle size (DPS) on dry sliding wear behaviour of LM30/sillimanite composites

The effect of dual particle size (DPS) reinforcement (fine:coarse in weight ratios of 1:3, 1:1, and 3:1) on wear behaviour of LM30/sillimanite composites is reported. Optical micrographs revealed uniform distribution of particles in the matrix. Al2Si4O10 phase was observed using XRD owing to the interfacial reactions of particle with matrix. Further, high nanohardness values of interface revealed sound particle-matrix bonding. The wear resistance of 15 wt.% DPS composites with weight ratio 3:1 improved by 59% over base alloy. In-addition, the results were comparable with the mathematical model and with cast iron used in brake drum applications. SEM-EDS analysis revealed that at low contact pressure, abrasive/adhesive wear mechanism was dominant, whereas at higher contact pressure delamination wear was dominant.

Effect of single particle size, double particle size and triple particle size Al2O3 in Nylon-6 matrix on mechanical properties of feed stock filament for FDM

Fused Deposition modelling (FDM) is one of the additive manufacturing (AM) technologies used extensively for modelling and prototyping applications. In commercial FDM setup, filament wire is uncoiled from wire spools and plastic based material is supplied to produce the part. The application area of FDM is limited presently due to selective material availability in market. Some researchers have highlighted the use of reinforced composite wires as FDM filament. But hitherto no work has been reported on the effect of Single particle size (SPS), Dual particle size (DPS), Triple particle size (TPS) of Al2O3 (as reinforcement) in Nylon-6 matrix to be used as feed stock filament for FDM. In this paper, effect of SPS, DPS, and TPS of Al2O3 (as reinforcement) in Nylon-6 matrix on mechanical properties (like: percent age elongation, tensile strength, yield strength, Young's modulus) has been studied. Further, empirical relations have been developed for above mentioned properties and a surface characteristic of developed wires has been observed with SEM image.

Effect of Single, Double and Triple Particle Size SiC and Al2O3 Reinforcement on Wear Properties of AMC Prepared by Stir Casting in Vacuum Mould

The aim of present research work is to study the effect of single particle size (SPS), dual particle size (DPS) and triple particle size (TPS) of SiC and Al2O3 reinforcement as hybrid solute on wear properties of aluminium matrix composite (AMC) prepared by stir casting in vacuum mould. The ABS plastic based master pattern (prepared with fused deposition modelling setup) for vacuum mould has been used in the present study. The friction and wear tests were carried out using a pin-on-disc type tribo-test machine under dry sliding condition. The results of study suggest that SPS based AMC exhibited better wear resistant properties as compared to DPS and TPS. The study also highlights the effect of other controllable process parameters of vacuum moulding process (namely: vacuum pressure, sand grain size and proportion of solutes) on wear behavior of AMC.

Investigation of the low-speed impact behavior of dual particle size metal matrix composites

SiC-reinforced aluminum matrix composites were manufactured by powder metallurgy using either single or dual particle sized SiC powders and samples sintered under argon atmosphere. Quasi-static loading, low-speed impact tests and hardness tests were used to investigate mechanical behavior and found that dual particle size composites had improved hardness and impact performance compared to single particle size composites. Sample microstructure, particle distributions, plastic deformations and post-testing damages were examined by scanning electron microscopy and identified microstructure agglomerations in SPS composites. Impact traces were characterized by broken and missing SiC particles and plastically deformed composite areas.

Wear Behavior at High Temperature of Dual-Particle Size Zircon-Sand-Reinforced Aluminum Alloy Composite

The basic aim of the present investigation is to study the role of particle size for high-temperature application of ZrSiO4-reinforced aluminum-based LM13 alloy composite as a bearing material. Composites containing 15 wt pct ZrSiO4 particles of two different size ranges (20 to 32 and 106 to 125 μm) in different proportion were prepared by the stir casting route. The microhardness measured at different areas indicates good interfacial bonding. Transition in the wear mode for all composites occurs after temperature 423 K (150 °C). The overall wear properties of DPS-2 composite containing 12 pct fine and 3 pct coarse particles are better at all temperatures for both low and high loads.