Phase Particles Research Articles

Relative Humidity-Dependent Phase Transitions in Submicron Respiratory Aerosols.

Respiratory viruses, such as influenza and severe acute respiratory syndrome coronavirus 2, represent a substantial public health burden and are largely transmitted through respiratory droplets and aerosols. Environmental factors such as relative humidity (RH) and temperature impact virus transmission rates, and a precise mechanistic understanding of the connection between these environmental factors and virus transmission would improve efforts to mitigate respiratory disease transmission. Previous studies on supermicrometer particles observed RH-dependent phase transitions and linked particle phase state to virus viability. Phase transitions in atmospheric aerosols are dependent on size in the submicrometer range, and actual respiratory particles are expelled over a large size range, including submicrometer aerosols that can transmit diseases over long distances. Here, we directly investigated the phase transitions of submicrometer model respiratory aerosols. A probe molecule, Nile red, was added to particle systems including multiple mucin/salt mixtures, a growth medium, and simulated lung fluid. For each system, the polarity-dependent fluorescence emission was measured following RH conditioning. Notably, the fluorescence measurements of mucin/NaCl and Dulbecco's modified Eagle's medium particles indicated that liquid-liquid phase separation (LLPS) also occurs in submicron particles, suggesting that LLPS can also impact the viability of viruses in submicron particles and thus affect aerosol virus transmission. Furthermore, the utility of fluorescence-based measurements to study submicrometer respiratory particle physicochemical properties in situ is demonstrated.

Influence mechanism of solution temperature on microstructure evolution and tensile properties of Ti microalloyed high strength steel CGLC700

The influence mechanism of solution temperature on the strength and toughness of Ti microalloyed steel CGLC700 was studied. The microstructure changes of Ti microalloyed steel were observed by micro-electron microscopy, and the mechanical properties were evaluated by tensile test. The appropriate solution temperature can promote the solid solution of Ti atoms and the formation of small-sized TiN, TiC and other particles, hinder the movement of dislocations, and improve the tensile properties of steel. When the solution temperature is 1240 °C (2#), the grain size of steel is the lowest, the proportion of high angle grain boundary is the highest, and the tensile properties of steel are the best. Ti microalloyed steels increased tensile strength by 4.12%, yield strength by 2.85% and elongation by 28.4%. Too low or too high solid solution temperatures weaken the strengthening effect of the microalloying elements and led to a reduction in the tensile properties of the steel. This can be attributed to the low solid solution of Ti at low solid solution temperatures and the growth of second phase particles and inclusions at too high solid solution temperatures. This study provides a theoretical basis for optimizing the heat treatment process of Ti microalloyed steel.

Dynamics of meniscus-bound particle clusters in extensional flow

Capillary suspensions are three-phase mixtures containing a solid particulate phase, a continuous liquid phase, and a second immiscible liquid forming capillary bridges between particles. Capillary suspensions are encountered in a wide array of applications including 3D printing, porous materials, and food formulations, but despite recent progress, the micromechanics of particle clusters in flow is not fully understood. In this work, we study the dynamics of meniscus-bound particle clusters in planar extensional flow using a Stokes trap, which is an automated flow control technique that allows for precise manipulation of freely suspended particles or particle clusters in flow. Focusing on the case of a two-particle doublet, we use a combination of experiments and analytical modeling to understand how particle clusters rearrange, deform, and ultimately break up in extensional flow. The time required for cluster breakup is quantified as a function of capillary number Ca and meniscus volume V. Importantly, a critical capillary number Cacrit for cluster breakup is determined using a combination of experiments and modeling. Cluster relaxation experiments are also performed by deforming particle clusters in flow, followed by flow cessation prior to breakup and observing cluster relaxation dynamics under zero-flow conditions. In all cases, experiments are complemented by an analytical model that accounts for capillary forces, lubrication forces, hydrodynamic drag forces, and hydrodynamic interactions acting on the particles. Results from the analytical models are found to be in good agreement with experiments. Overall, this work provides a new quantitative understanding of the deformation dynamics of capillary clusters in extensional flow.

Stirrer design for improving fluidization of cohesive powder: A time-resolved X-ray study

Stirring has been recognized in the literature as a promising technique for facilitating fluidization of cohesive powders, via inputting additional energy to counteract interparticle forces. However, the influence of operating conditions and stirrer configurations on flow behavior remains largely unknown, which impedes the practical implementation of stirred fluidization. Utilizing X-ray imaging, this research demonstrates that stirring enhances fluidization in cohesive micron-silica powder (Sauter mean diameter ▪) by collapsing the powder packing structure, and transitioning channeling beds into bubbling states. Comb-like configurations featuring fewer stirrers and blades, placed in the bottom region, have shown to be highly effective. Excessive stirring can lead to air pockets and a compacted phase of particles on the column walls, undermining the interaction between particles and stirrers. Additionally, the experiments show that maximizing the sweeping coverage, employing complex asymmetrical configurations, and avoiding tortuous gas pathways are preferable.

A Numerical Case Study of Particle Flow and Solar Radiation Transfer in a Compound Parabolic Concentrator (CPC) Photocatalytic Reactor for Hydrogen Production

Compound parabolic concentrator (CPC) photocatalytic reactors are commonly used for photocatalytic water splitting in hydrogen production. This study aimed to gain a better understanding of the physical processes in CPC photocatalytic reactors and provide theoretical support for their design, optimization, and operation. The analysis involved the ray tracing approach, Euler–Euler two-fluid model, and discrete ordinates method (DOM) to study solar radiation transfer and particle flow in the reactor. The distribution of solar radiation on the receiving tube’s surface after CPC concentration was obtained by conducting the ray tracing approach. This solar radiation distribution was then coupled into the Euler–Euler two-fluid model to solve for the natural convection flow field, the temperature field, and particle phase volume fraction distribution inside the receiving tube over a period of 120 s. Lastly, the discrete ordinates method (DOM) was used to analyze the transfer of radiation inside the receiving tube at different times, obtaining the distribution of local volume radiative power absorption (LVRPA) and the total radiative power absorption (TRPA) inside the tube. The results showed that the TRPA reached its maximum at 120 s, accounting for 66.61% of the incident solar UV radiation. According to the above results, it could be suggested that adopting an intermittent operation mode in CPC photocatalytic reactors is reasonable and efficient.

Manufacturing profiled conical cylinder by a semi-closed isothermal precision die forging technology

An improved semi-closed isothermal precision dies forging process has been used to produce successfully precision profiled conical cylinder forging. The semi-closed die forging significantly improved the forming quality and deformation homogeneity of profiled forgings, and greatly reduced die forging force by isothermal forging with three-stage variable speed. The static recrystallization during solution process was inhibited, and fine and even dynamic recrystallized grains and abundant sub-grains were obtained. In addition, the difference of the microstructure at each position was small and the distribution of grains and second phase particles was uniform. This significantly improved the mechanical properties and homogeneity of forgings, and the average values of tensile strength, yield strength and elongation reached 480.9 MPa, 387.8 MPa and 8.75%, respectively.

Development of an analytical method for the determination of more than 300 pesticides and metabolites in the particulate and gaseous phase of ambient air

Pesticides can enter the atmosphere during spraying or after application, resulting in environmental or human exposure. The study describes the optimisation and validation of analytical methods for the determination of more than 300 pesticides in the particulate and gaseous phases of the air. Pesticides were sampled with high-volume air samplers on glass-fibre filters (GFFs) and glass columns filled with polyurethane foam (PUF) and XAD-2 resin. Comparing different extraction methods, a QuEChERS extraction with acetonitrile was selected for the GFFs. For the PUF/XAD-2 columns, a cold-column extraction with dichloromethane was used. Instrumental determination was performed using liquid chromatography/electrospray ionisation-time-of-flight mass spectrometry (LC/ESI-QTOF) and gas chromatography/electron impact ionisation-tandem mass spectrometry (GC/EI-MS/MS). Recovery experiments showed recovery rates between 70 and 120% for 263 compounds on the GFFs and 75 compounds on the PUF/XAD-2 columns. Semi-quantitative determination was performed for 39 compounds on the GFFs and 110 compounds on the PUF/XAD-2 columns. Finally, 27 compounds on the GFFs and 138 compounds on the PUF/XAD-2 columns could be determined only qualitatively. For the determination of the PUF/XAD-2 samples, signal suppression (LC) or signal enhancement (GC) due to matrix effects were determined. Method quantification limits of the optimised methods ranged from 30 to 240 pg/m3 for the target compounds on the GFFs, and from 8 to 60 pg/m3 on the PUF/XAD-2 columns. The applicability of the method was demonstrated by means of environmental air samples from an agricultural area in the Netherlands.

Effect of borax on the hydration and hardening of β-hemihydrate gypsum at high water–plaster ratio

The existing methods of preparing lightweight gypsum blocks are to make hollow slats or to make foamed blocks, both of which are defective and fail to meet the standards. In order to prepare lightweight gypsum blocks, this paper investigates the method of increasing the proportion of moisture to reduce the weight of gypsum blocks. To further understand the performance relation between β-hemihydrate gypsum (β-hemihydrate phosphogypsum and β-hemihydrate flue-gas desulfurization gypsum) and its products, the effect of borax on the hydration and hardening of β-hemihydrate gypsum at high water–plaster ratio was studied. The results showed that with an increase in borax dosage, the setting time of β-hemihydrate phosphogypsum (β-HPG) was evidently prolonged; the initial setting time increased from 15 to 62 min, and the final setting time increased from 22 to 93 min. The difference between the initial and final setting times also increased, and the fluidity of the gypsum slurry was improved. When the borax dosage reached 0.5%, the flexural strength of β-hemihydrate flue-gas desulfurization gypsum (β-HFGD) increased from 5.2 to 6.3 MPa and the compressive strength increased from 4.7 to 9.3 MPa after 28 d. By analyzing the changes in phase transition, hydration degree, infrared spectrum, particle size, and crystal microstructure during the hydration of β-hemihydrate gypsum, it was found that β-HPG was more sensitive to borax than β-HFGD at high water–plaster ratio and β-HFGD showed superior mechanical properties. The study findings will provide a theoretical basis for the application of β-hemihydrate gypsum products under humid conditions and expand the application range of gypsum products.

A multi-frequency ultrasonic method for nondestructive detection of setting times and internal structure transition of building materials

Setting times of building materials are crucial factors in the construction industry, as they directly affect the construction process. Accurate determination of setting times is essential to ensure that construction materials meet design requirements before demolding. This study introduces a new method using longitudinal waves with multi-frequencies to nondestructively determine the setting times of building materials. The measurement performance was examined by comparing the wave velocity with the results obtained using Vicat and calorimetry methods. A broad range of frequencies was applied to capture the transition of particle size and phase densification during the hardening process. The results showed that the collected data, including SEM images, and formation/transformation of chemical structures, supported the high accuracy in measuring the setting times via velocity regardless of sample type and hardness condition. Furthermore, by utilizing multi-frequencies, the proposed setup improved the detection sensitivity, capable of quantitatively monitoring the modification of internal structures during the monitoring period.

Thermal dynamics assessment for multi-phase flow analysis with motile cilia and electric double layer effects: Application of Levenberg–Marquardt backpropagation NNs

Ciliary movement holds substantial importance in the realm of biomedical research. Disorders arising from impaired ciliary motion, such as primary ciliary dyskinesia and specific respiratory ailments, underscore the critical need to investigate both the normal functioning and dysfunction of cilia. Such research is fundamental to the development of effective treatments and therapies. This work explores the application of Levenberg–Marquardt backpropagation neural networks (LMBP-NNs) for simulating the flow of a non-Newtonian Jeffery fluid in peristaltic motion. Inspired by synchronous ciliary movement, microfluidic systems mimicking cilia functionality have been developed. These artificial cilia can generate controlled fluid flow patterns, enabling various applications such as drug delivery, mixing, and particle sorting in lab-on-a-chip devices. The present study focuses on measuring thermal and mass transfer in beating cilia during multiphase peristaltic pumping of Jeffery fluid in two- and three-dimensional channels using transverse magnetohydrodynamics in a porous medium. The governing equations for the non-Newtonian Jeffery fluid in both the fluid and dusty phases are formulated, and exact solutions are calculated for fluid phase velocity, particulate phase velocity, temperature, concentration, and pressure gradient. The physical behavior is investigated by graphing dimensionless parameters for velocity, temperature, and concentration profiles in both solid and liquid phases. The trapping phenomena is depicted by showing streamlines of various dimensionless characteristics such as porosity velocity and volume percentage. The LMBP-NNs approach is then used to train, test, and verify the neural network models using the reference datasets. The accuracy of the LMBP-NN is assessed using statistical data such as mean square error, curve fitting graphs, regression plots, and error histograms. The study also investigates flow model limits for momentum, temperature, and concentration profiles using visual representations. This study illustrates the computational capability of LMBP-NNs in modeling the peristaltic flow of Jeffery fluid and gives useful insights into fluid flow behavior in microfluidic devices containing artificial cilia. The findings help to better understand and optimize these systems for a variety of fluid manipulation and transportation applications.

Influence of minor cerium addition on microstructure and fluidity of as-cast Al-Cu-Mn-Mg alloy

Al-Cu-Mn alloys are widely used to produce automobile components like cylinder heads and engine blocks because of their capability to retain excellent thermal and mechanical characteristics at high temperatures. However, the Al-Cu-Mn-based alloys demonstrate restricted fluidity, leading to casting defects such as shrinkage and incomplete filling. This research investigated the microstructure and fluidity of Al-4.7Cu-1.0Mn-0.5Mg (wt%) alloy with minor cerium (Ce) addition. The as-cast alloys predominantly comprise α-Al matrix, accompanied by the presence of Al2Cu, Al6Mn, and Al8Cu4Ce phases. The influence of adding Ce on the fluidity of the Al-4.7Cu-1.0Mn-0.5Mg alloy was investigated using a tri-spiral fluidity test mold in this research. The findings suggest that the addition of Ce within the range of 0.1 wt% to 0.5 wt% in the Al-4.7Cu-1.0Mn-0.5Mg alloy results in an enhancement in fluidity. Specifically, the alloy containing 0.4 wt% Ce exhibits a significant increase in fluidity distance, from 349.7 to 485.7 mm. This improvement can be attributed to the reduction in viscosity, the refinement of secondary dendrite arm spacing, and the modification of secondary phase particles. However, a higher concentration of Ce leads to a decrease in fluidity length, potentially due to the formation of Al8Cu4Ce.

Synthesis and wear characterization of Al7075/molybdenum disulfide/zirconium diboride hybrid composites

AbstractThe manuscript presents the synthesis and dry sliding wear performance of Al7075 alloy‐based composites. Five compositions namely Al7075 alloy, Al7075+3 vol % molybdenum disulfide, Al7075+3 vol % molybdenum disulfide+3 vol % zirconium diboride, Al7075+3 vol % molybdenum disulfide+6 vol % zirconium diboride and Al7075+3 vol % molybdenum disulfide+9 vol % zirconium diboride were stir cast and characterized for hardness, x‐ray diffraction, microstructure, and tribological properties. In‐situ formed zirconium diboride particles increase the hardness of Al7075 alloy whereas molybdenum disulfide shows the opposite trend due to its self‐lubricating nature. X‐ray diffraction analysis identifies subsequent phase particles in the matrix while microstructural images exhibit the dispersion and morphology of reinforcement particles. The wear tests and friction coefficient were analyzed with variations of sliding velocity, normal load, sliding distance, and compositions. Further, the obtained wear results were also correlated with microstructure and wear surface topography. Al7075+3 vol % molybdenum disulfide composite shows the lowest coefficient of friction because of its self‐lubricating nature. Al7075+3 vol % molybdenum disulfide+9 vol % zirconium diboride hybrid composite exhibits the lowest wear rate at high velocity as well as at high load and can be potentially used in manufacturing and tribological applications. Moreover, the use of this material may lead to the minimum requirement of external toxic lubricants that make it cost‐effective and environmentally sustainable.

The microstructure and properties of Mo0.5NbTiZrTax high entropy alloys enhanced by Ta addition

In this study, the Mo0.5NbTiZrTax (x = 0.3, 0.5, 0.7) HEAs obtained by arc melting were controlled by the change of Ta content. The microstructure, the wear properties, and the corrosion resistance of the alloys were studied systematically. The results revealed that the alloys have the BCC (major) phase + BCC (minor) phase structure. At the same time, the increase in Ta content promotes the refinement of grains and the formation of sub-grains with gradually random orientation at grain boundaries but suppresses the randomization of crystal orientation. This also enriched the defect structure inside the alloys, further induced the formation of Zr-rich second phase particles, high-density stacking fault structures, and disordered Zr-rich BCC phases. The increase in Ta content significantly improved the wear properties of the alloys, which is mainly ascribed to the presence of the tough BCC phase and the combined effects of solid solution strengthening, second phase strengthening, fine grain strengthening, lattice distortion effect, and stacking fault strengthening. The electrochemical measurements confirm that the overall corrosion resistance of the alloys shows a trend of first increasing and then decreasing with the increase of Ta content due to the formation of micro batteries between the second phase rich in Zr as the anode and dendrites.

Concomitant determination of PAH, PCBs, and phthalates in indoor air and dust from residential houses in the Strasbourg region of France

Global attention is drawn to the significant issue of indoor pollution, given its direct negative impact on human health and wellness. Typically, individuals can nowadays spend 80% or more of their time in enclosed built locations where they can be prone to a multitude of harmful toxic chemicals distributed in particulate and gas phases. Therefore, a systematic efficient monitoring of such chemicals in indoor environments is urgently required to devise and implement various measures that allow their control. The objective of this study is to evaluate the concomitance occurrence of phthalates, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) within the indoor settings of residential homes in Strasbourg. It focused on both the indoor air and dust samples collected in nine residential homes in Strasbourg for a one-year sampling period, February 2016 - February 2017. For this, Radiello®, SiC© foams, and Tenax-TA® were successfully introduced and used as reliable passive samplers for the aforementioned matrices. Extractions were carried out using pressurized solvent extraction (PSE) followed by ATD-GC/MSMS analysis. The findings of the presented study revealed that 12 PAHs, 18 PCBs, and 7 phthalates were regularly perceived in the indoor environments of the houses under assessment. In gaseous samples, the average concentrations of the detected pollutant were approximately 3,919, 4.3, and 601.6 ng/sampler for PAHs, PCBs, and phthalates, respectively. As for dust samples, the average concentrations of the detected pollutant were approximately 3,438, 6.2, and 1,816.2 ng/g, respectively. The obtained results showed that PCBs exhibited the lowest concentration in both matrices. However, air samples were mostly contaminated by PAHs, while dust samples showed higher levels of phthalates. These results are correlated to the physico-chemical properties of these compounds and to their origin and source of emission. The findings of this study stress the importance of indoor pollution assessment so that the risks associated with it could be controlled.

Mechanism of improving solidification structure of super austenitic stainless steel by feeding strip into molten steel

Feeding steel strip into molten steel is an effective technique for refining the solidification structure of steel, especially for high-alloy steel. This study experimentally and numerically investigated the effects of feeding strip on the solidification structure of super austenitic stainless steel S32654. The results revealed that feeding strip noticeably increased the proportion of equiaxed grains, refined the dendritic structure, and improved Mo segregation and the precipitation of σ phase. The relevant mechanism was clarified as follows. Firstly, feeding strip promoted the formation and survival of a large number of floating dendrites by cooling the molten steel. As the temperature decreased, these floating dendrites sharply increased their quantity by repeated splitting and then acted as nucleation particles. Numerous equiaxed grains grew around these floating dendrites, significantly refining the central dendritic structure. Meanwhile, the doubling of the equiaxed grains has two effects on Mo segregation. First, it prevented the growth of columnar grains and the movement of Mo segregation interface towards the center, thus reducing the Mo macrosegregation. On the other hand, it dispersed and refined the residual liquid phase (Mo segregation regions), thereby reducing the Mo microsegregation. Additionally, the reduced Mo segregation lowered the σ phase precipitation temperature, allowing it to form in solid austenite with a shortened growth duration. The lighter Mo segregation and slower Mo diffusion in solid austenite led to insufficient Mo supply for the σ phase growth. Moreover, dendritic refinement limited the growth space of the σ phase. Finally, less and finer σ phase particles precipitated in the S32654 steel fed with strip. The improvement of feeding strip on the solidification structure will reduce the temperature and time required for high-temperature homogenization, which is beneficial for the subsequent hot working.

Magnetite-ferrocyanide-copper sorbents for recovery of cesium ions from low-activity liquid radioactive waters

The article is devoted to the development of nanoscale sorbents based on copper ferrocyanide and magnetites for the removal of cesium, strontium, and heavy metal ions in their simultaneous presence in a multicomponent two-phase low-level radioactive solution containing complexing agents and surfactants. It they noted that the highest values of cesium ion removal from low-level radioactive water - 99.96% and 99.62% - are obtained with sorbents based on 100% copper ferrocyanide and a mixture of copper ferrocyanide and industrial magnetite in a ratio of 2 to 1. The efficiency of the sorbents in terms of the distribution coefficient is 2394 and 1589.7 ml/g, which ensures the purification of radioactive water from trace concentrations of cesium ions to values of 2394 and 265.11. These sorbents provide water purification to values less than 2 Bq/cm3, which is typical for 1-4 classes of water quality in terms of radiation safety of groundwater and surface water as sources of centralised drinking water supply. It is noted that sorption of cesium ions on copper ferrocyanide and magnetite is carried out in the presence of water molecules and hydroxo groups. It is shown that artificial magnetite in its pure form exceeds the sorption capacity of industrial magnetite. This is due to the difference in the phase composition and particle size of the crystals. The results obtained will be use as components of the technological process in the Plasma-Sorb technology developed at the State Institution "The Institute of Environmental Geochemistry" of the National Academy of Sciences of Ukraine for the treatment of low- and intermediate-level radioactive water from Ukrainian nuclear power plants.

Evolution of Mechanical Properties and Corrosion Resistance of Al-Zn-Mg Alloy with Different Numbers of Flame Rectification at 350°C

This paper investigated the microstructure, tensile properties, intergranular corrosion resistance and exfoliation corrosion resistance of Al-4.5Zn-1.5Mg (wt.%) alloy after undergoing different numbers of flame rectification at 350°C. The results showed that in the flame correction area, the mechanical properties of Al-4.5Zn-1.5Mg(wt.%) alloy with two times of flame correction is the best. The maximum tensile strength and elongation of Al-4.5Zn-1.5Mg(wt.%) alloy inside the region of flame correction are 387MPa and 26.37% respectively. The flame rectification accelerated the corrosion susceptibility of Al-4.5Zn-1.5Mg (wt.%) alloy. The maximum intergranular corrosion depth is detected with the value of 105μm after one time of FR. The corrosion property of Al-4.5Zn-1.5Mg(wt.%) alloy is mainly related to the formation of galvanic couple. The uneven distribution of the second phase particles of Al-4.5Zn-1.5Mg(wt.%) alloys results in different corrosion potentials at grain boundaries and within grains, leading to galvanic corrosion.

Investigation of Copper Codeposits with SiC Nano from Ionic Liquid (Ethaline) as Function of Concentration and Micro Particles Sizes where the Working Electrode in ‘Vertical’ Position Using Acoustic Impedance Electrochemical Quartz Crystal Microbalance (EQCM)

The gravimetric inspection of co-electrodeposited copper, with hard inert second phase ceramics SiC and 0.02 M [CuCl2.2H2O] in 1 ChCl: 2 EG, based liquid for different solution-phase loadings of 1-3 \(\mu\)m silicon carbide unpolished gold AT cut working electrode placed in’Vertical’ position, revealed that the EQCM method admits the first in-situ quantification or particulate inclusion. It was found that the composition of incorporated substance was fairly dependant on the concentration of second phase particles in solution, where in this study the 5% SiC has the amount in the copper which is in a good agreement with alumina particles with the same size. Another observation was that most of the material was drawn onto the surface rather than settling on to it, however the distribution of the hard phase was found to be reasonably even throughout the coating. This technology is important because it assists deposition of bright copper coatings without adding hazard materials, such as cyanide. On the other hand the comparison between concentrations of 0.02 M and 0.2 M [CuCl2.2H2O] in 1 ChCl: 2 EG based liquid for 10% solution-phase loadings of 45-55 nm size silicon carbide was also investigated, where the working electrode is placed in’Horizontal’ postion. It is very interisting that the experimental result showed that the mass loaded by 0.2 M solution is about 10 times greater than for the mass loaded by 0.02 M solution.

Phosphorus-Based Flame-Retardant Acrylonitrile Butadiene Styrene Copolymer with Enhanced Mechanical Properties by Combining Ultrahigh Molecular Weight Silicone Rubber and Ethylene Methyl Acrylate Copolymer.

The present work proposes to investigate the effect of an ultrahigh molecular weight silicone rubber (UHMW-SR) and two ethylene methyl acrylate copolymers (EMA) with different methyl acrylate (MA) content on the mechanical and fire performance of a fireproof acrylonitrile butadiene styrene copolymer (ABS) composite, with an optimum amount of ammonium polyphosphate (APP) and aluminum diethyl phosphinate (AlPi). ABS formulations with a global flame retardant weight content of 20 wt.% (ABS P) were melt-compounded, with and without EMA and UHMW-SR, in a Brabender mixer. During this batch process, ABS P formulations with UHMW-SR and/or EMA registered lower torque values than those of ABS P. By means of scanning electron microscopy (SEM), it was possible to observe that all ABS composites exhibited a homogenous structure without phase separation or particle agglomeration. Slightly improved interfacial interaction between the well-dispersed flame-retardant particles in the presence of EMA and/or UHMW-SR was also noticed. Furthermore, synergies in mechanical properties by adding both EMA and UHMW-SR into ABS P were ascertained. An enhancement of molecular mobility that contributed to the softening of ABS P was observed under dynamic mechanical thermal analysis (DMTA). An improvement of its flexibility, ductility and toughness were also registered under three-point-bending trials, and even more remarkable synergies were noticed in Charpy notched impact strength. Particularly, a 212% increase was achieved when 5 wt.% of EMA with 29 wt.% of MA and 2 wt.% of UHMW-SR in ABS P (ABS E29 S P) were added. Thermogravimetric analysis (TGA) showed that the presence of EMA copolymers in ABS P formulations did not interfere with its thermal decomposition, whereas UHMW-SR presence decreased its thermal stability at the beginning of the decomposition. Although the addition of EMA or UHMW-SR, as well as the combination of both in ABS P increased the pHRR in cone calorimetry, UL 94 V-0 classification was maintained for all flame-retarded ABS composites. In addition, through SEM analysis of cone calorimetry sample residue, a more cohesive surface char layer, with Si-O-C network formation confirmed by Fourier transform infrared (FTIR), was shown in ABS P formulations with UHMW-SR.

Effect of reaction temperature and impact force on formation and particle shape of β-Li3PS4 in liquid phase synthesis

All-solid-state lithium-ion batteries are promising next-generation secondary batteries, primarily due to their superior safety. In their production process, it is necessary to achieve large contact interfaces between the particles and improve particle fluidity. The particle shape of the solid electrolyte plays a key role in addressing these requirements. Li3PS4 (LPS) is synthesized in the liquid phase and offers the advantages of cost-effectiveness and production-scalability. However, the mechanisms controlling the particle size and shape have not yet been revealed. In this study, we synthesized LPS particles in the liquid phase using a hot stirrer and an ultrasonic homogenizer to investigate the effects of reaction temperature and impact force on the reaction rate and particle shape. We successfully synthesized shape-controlled particles with high ionic conductivity by combining different synthesis methods. This study provides valuable data for optimizing the synthesis conditions to attain specific particle shapes and sizes.