Varying Particle Size Research Articles

AIE-labeled fluorescent polystyrene nanoplastics for quantitative analysis in macrophages uptake

Nanoplastics have attracted significant attention due to their harmful effects on the environment and organisms. However, accurately detecting and quantifying nanoplastics that are ingested by organisms poses a challenge. Conventional organic fluorescent-labeled nanoplastics have reduced labeling efficiency due to aggregation-caused quenching (ACQ), leading to artifacts caused by leakage of fluorescent molecules. To address these limitations, this study utilized AIE fluorescence for internally labeling polystyrene nanoparticles. AIE-active molecules do not emit fluorescence in dilute solutions, thus preventing accuracy issues associated with fluorescence leakage. Three model plastics (TPE@PS) of varying particle sizes were synthesized via the swelling method. The preparation parameters were optimized, followed by stability tests conducted on TPE@PS. Fluorescence microscopy imaging revealed significant uptake of TPE@PS by RAW246.7 cells. A successful standard curve of fluorescence intensity-concentration was established successfully and utilized to accurately quantify the amount of TPE@PS that was ingested by RAW246.7 cells. The results indicate a consistent increase with increasing concentration in TPE@PS uptake across all particle sizes during the fixed exposure duration of 48 h. Furthermore, RAW264.7 cells exhibited a higher propensity to uptake smaller TPE@PS particles. Flow cytometry was also employed to validated the suitability of TPE@PS as a model nanoplastic for tracing purposes.

Replacing Fly Ash or Silica Fume with Tuff Powder for Concrete Engineering in Plateau Areas: Hydration Mechanism and Feasibility Study

Abundant tuff mineral resources offer a promising solution to the shortage of fly ash (FA) and silica fume (SF) resources as emerging supplementary cementitious materials. However, a lack of clarity on its hydration mechanism has hindered its practical engineering application. In this study, high SiO2-content tuff powder (TP) was examined to assess the mechanical and workability performance of mortar specimens with varying particle sizes of the TP as complete replacements for FA or SF. Microscopic analysis techniques, including X-ray diffraction (XRD), differential thermal analysis (DTG), and energy-dispersive X-ray spectroscopy (EDS), were employed to elucidate the hydration mechanism of the TP and its feasibility as a substitute for SF or FA. Results indicated that TP primarily functions as nuclei and filler, promoting cement hydration, with smaller particle sizes amplifying the hydration ability and increasing Ca(OH)2 and C-S-H gel content. The specimens with TP (median particle size 7.58 μm) demonstrated 9.2% and 29.9% higher flexural and compressive strengths at 28 days, respectively, compared to the FA specimens of equal mass. However, fluidity decreased by 23.1% accordingly. Due to TP’s smaller specific surface area compared to SF, the TP specimens exhibited higher fluidity but with decreased strength relative to the SF specimens. Overall, TP shows potential as a replacement for FA with additional measures to ensure workability.

Enhanced dewaterability of waste activated sludge via peroxymonosulfate activation process initiated by magnetic biochar derived from iron-rich sludge

The reduction of water content (WC) in waste activated sludge (WAS) is crucial for the recycling and environmentally-friendly treatment sludge in wastewater treatment plants. A new process of combined conditioning of iron-rich sludge biochar (Fe-BC) and peroxymonosulfate (PMS) was proposed and verified to enhance the dewaterability of WAS. The WC of sludge cake decreased significantly from 85.76% to 76.29% after Fe-BC/PMS treatment. For sludge extracellular polymeric substances (EPS) in sludge, the content of protein and polysaccharide in both TB-EPS and LB-EPS exhibited a decrease after Fe-BC/PMS treatment, whereas the S-EPS demonstrated an increase. Three-dimensional fluorescence (3D-EEM) showed that the fluorescence regions of protein-like and soluble microorganisms in both LB-EPS and TB-EPS were weakened. Through the experiment of free radical quenching, it has been demonstrated that the SO4•− and •OH as the primary oxidant in the Fe-BC/PMS system, effectively degrade proteinaceous components and humic substances present in sludge. The variation of particle size showed that the damaged EPS appeared reflocculation and achieved deep dehydration with Fe-BC as the skeleton. Consequently, a four-step mechanism was proposed for Fe-BC/PMS process, namely, oxidation cracking-sludge biochar flocculation-skeleton support – Fe2+ and Fe3+ reflocculation, which demonstrated the combined process with superior sludge dewatering effect and application potential.

Effect of milling and compaction on sintering of porcelain stoneware tiles

The present study aims to provide a deeper understanding of how different particle size distributions and degrees of powder compaction affect the densification process of porcelain stoneware tiles. For this purpose, three different batches underwent a laboratory simulation of the industrial tilemaking process, at growing grinding time or increasing forming pressure, with technological characterization of both unfired and fired products. Sintering behaviour was determined by hot-stage microscopy. Phase composition was determined by XRD-Rietveld allowing the estimation of the chemical composition and physical properties of the liquid phase. The results illustrate the impact of too fine (or too coarse) grain size on powder compaction, firing shrinkage, water absorption, efficiency of densification, sintering rate, stability at high temperature, and risk of anticipated overfiring (and similarly for too high or too low forming pressure). Simultaneous variation of particle size and forming pressure beyond usual standards induced changes in technological behaviour that in most cases compensate each other. Phase composition is moderately influenced by particle size and little by powder compaction. The vitreous phase mainly suffered from a decreasing degree of polymerization as the particle size became finer or the dry bulk density decreased. In case of insufficient grinding, too much residual feldspars caused improper composition and properties of the glassy phase, which resulted in lower efficiency of densification and slower sintering rate. Both the sintering kinetics and degree of densification depend on the timescale, i.e. the ratio of surface tension to viscosity (melt) and median particle size. Nevertheless, a low powder compaction can trigger a microstructural effect on sintering (improving both densification rate and efficiency) that may outweigh the timescale effect.

Rheology of magnetorheological shear thickening polishing fluids with micro diamond abrasive particles

Magnetorheological shear thickening polishing (MRSTP) has the dual effect of shear thickening and magnetization enhancement, thereby enhancing polishing efficiency. MRSTP fluids (MRSTPFs) were prepared using polyethylene glycol (PEG), silicon dioxide (SiO2), carbonyl iron particles (CIPs), and diamond micro-abrasive particles. MRSTPFs containing diamond particles of various sizes were prepared for rheological tests. A rheological hypothesis was proposed regarding the development of CIPs chains and the ability to aggregate PEG and SiO2. Rheological tests results indicated that each sample exhibited shear thickening and magnetization enhancement effects under the magnetic field and shear rate. The shear thickening effect decreased with increasing magnetic flux density, while the overall viscosity and shear stress increased. As the magnetic flux density increased from 0 mT to 112 mT, the thickening ratio of MRSTPFs containing 3 μm diamond particles decreased from 18.94 to 1.37, but the peak viscosity increased from 5.208 Pa·s to 3639 Pa·s. The thickening ratios of MRSTPFs with different abrasive sizes showed a slight variation from 0.11 to 1.76 at the same magnetic flux density of 22 mT, 45 mT, 68 mT, 90 mT, and 112 mT, respectively. It demonstrated that the diamond particle size did not have a significant effect on the rheological properties of MRSTPFs. The correctness of the hypothesis was confirmed. The storage modulus of MRSTPFs exceeded the loss modulus at non-zero magnetic flux density, indicating that the MRSTPFs had become semi-solid. The microscopic mechanism showed that the rheological characteristics were determined by the evolution of the chain structure of CIPs and the binding ability of PEG to SiO2. This study provided valuable insights into exploring mechanisms of MRSTPFs and demonstrating the potential application of MRSTP.

Effect of wheat coarseness and pellet quality on performance and particle size preference of broiler chickens fed diets based on wheat and maize

Recent broiler experiments have demonstrated that the macrostructure defined as the diameter and length of pellets can be larger, and that the tolerance for fines in the diet is higher than currently assumed. In a first experiment, broiler performance till 10 d of age was not affected when a 3 mm pelleted diet was replaced with a 5 mm pelleted and crumbled diet (35% particles > 3.6 mm). Preference tests indicated either no particle size preference, or a preference for particles > 2.8 mm. In a second experiment, reducing pellet quality of 5 mm pellets to increase the amount of fines had no effect on weight gain and FCR from 10 to 34 d of age, but when diets consisted of finely ground wheat as compared to coarsely ground wheat, the feed intake was higher and FCR was poorer. When offered feed with particles > 4.0 mm, 2.8 – 4.0 mm, 1.6 – 2.8 mm and < 1.6 mm, broilers ate more particles 1.6 – 2.8 mm than > 4.0 mm at 12 d of age, while no clear particle size preferences were observed at older ages. These data confirm that diets pelleted through a 5 mm die can be used even from day-old, and that broilers can handle a moderate reduction in pellet quality of 5 mm pellets without compromising performance. A high versatility of broiler chickens to particle size variations, and a preference for larger particles than currently assumed even at a very young age, may explain these results.

Prediction of Conveying Resistance for a Novel Hydraulic-mechanical Hybrid Vertical Lifting System

Objective: Recently a novel hydraulic-mechanical hybrid vertical lifting system was proposed for deep-sea mining. Accurate prediction of conveying resistance is important for the engineering design of the system. Plug flow of coarse particles is the main flow regime in the system. So far rare attention has been paid to the pressure drop prediction of plug flow of coarse particles. This paper aims to investigate eight theoretical pressure drop models on the applicability to predict the pressure drop of plug flow. Methods: Eight theoretical pressure drop models were studied. In addition, a hydraulic-mechanical hybrid vertical lifting test setup was developed. The novelty of this experimental work is that plug flow of coarse particles is formed and the lifting force of the plug can be measured with the test setup. Tests were conducted with varying particle sizes, lifting speeds and plug weights. The particle size is varied among 13, 18, and 25mm. The lifting speed is varied from 0.02m/s to 0.1m/s. The plug weight varies from 5 to 10kg. The range of Reynolds number for the tested particles is between 208 and 2,000. Results: Prediction errors of eight pressure drop models are derived and compared with the experimental data collected during this study. It was found that similar prediction trends are observed for all pressure drop models under most test conditions. Except the Rose model, all models produce average prediction errors less than 15%. The average prediction error for the Rose model is 20.59%. The average prediction error for the Ergun model is 12.43%. Conclusion: From this study it can be seen that the Ergun model produces the smallest prediction error among the eight selected pressure drop models for the given experimental conditions. Therefore, the Ergun model is considered to be most applicable for the calculation of the conveying resistance for the proposed vertical lifting system.

Experimental study of flake graphite large-area explosion electron emission cathode performance based on particle size discrepancy

Graphite is the most commonly used large-area cathode material in the high-power vacuum electron device for its long life and good repetitive-frequency performance, but its particle size selection scheme has not been elucidated. Therefore, in the present work, the explosive electron emission properties of flake graphite large area explosive electron emission cathodes with varied particle sizes are studied. The 320 mesh flake graphite has a current delay reduction of 0.2–0.9 ns compared to other samples at the same peak voltage. According to the Murphy–Good equation, the emission performance of each sample during the priming stage was calculated, and the threshold characteristics of 320 mesh flake graphite were significantly better than the other samples. After the space charge limited current is formed, the plasma expansion rate of all samples is 1.2±0.2cm/μs with a difference not exceeding 4% between samples. Our research provides a strong basis for the selection of raw materials for graphite based large area explosive electron emission cathodes and contributes to the development of cross-field high-power vacuum devices.

A Stretchable Thermoelectric Device based on Direct Ink Writing of Liquid Metal and Multi‐Layer Lamination

AbstractWearable thermoelectric devices are widely used due to their ability to generate heat and cool rapidly without the need for bulky external equipment. Researchers have explored methods to enhance flexibility and stretchability by incorporating liquid metal as an electrode. However, the challenge lies in the low thermal conductivity of the polymer, which hampers heating and cooling performance. Traditional methods, like molding and spraying, increase the thickness of both liquid metal and polymer channels, but this added thickness does not significantly improve the device's stretchability.[1, 2] To overcome these issues, this paper proposes a stretchable thermoelectric device (STED), which offers improved heating and cooling capabilities, as well as enhanced stretchability. To enhance the thermal conductivity of the polymer, Ag powder with varying particle sizes is mixed with the material. Additionally, the liquid metal is deposited using the direct ink writing (DIW) method, reducing the whole thickness of STED. The air layer is created by printing molten isomalt, which is subsequently removed using water. The proposed STED exhibits high stretchability, reaching up to 150 %, enabling flexible twisting in various directions. The double‐layer structure resulted in a maximum temperature decrease of 14 °C at room temperature.

Evaluation of the Effect of Particle Size and Biomass-to-Water Ratio on the Hydrothermal Carbonization of Sugarcane Bagasse

The generation of platform chemicals and hydrochar is of great interest because they reduce dependence on fossil resources and contribute to climate change mitigation by reducing carbon emissions. The main objective of this study was to evaluate the effect of biomass particle size and biomass-to-water ratio in a hydrothermal conversion system for the generation of value-added products obtained from sugarcane bagasse. Biomass characterization was performed using proximal, elemental, and structural analysis; hydrothermal carbonization was carried out at 220 and 260 °C for one hour; and conversion was monitored using pH, conductivity, and IR spectroscopy. Platform chemicals were quantified using HPLC-IR. Hydrochars were characterized by using scanning electron microscopy and energy dispersive spectroscopy. Optimizing biomass particle size and water ratio is crucial for maximizing the yield of platform chemicals and hydrochar. The study’s outcomes revealed that specific combinations, such as a biomass-to-water ratio of 1:50 and a particle size of 212 μm at 220 °C, resulted in a substantial 31.07% yield of platform chemicals on a dry basis. This highlights the critical role these parameters play in influencing the production efficiency of valuable chemicals. Furthermore, variations in biomass particle size and water ratio also affect the characteristics of hydrochar. For instance, utilizing a biomass-to-water ratio of 1:50 and a larger particle size of 600 μm at 260 °C led to the production of hydrochar with higher carbon content and increased porosity. These findings underscore how adjustments in these factors can impact not only chemical yields, but also the properties and quality of the resulting hydrochar.

Thermal effects on rheological characteristics and its evolution mechanism of bio-modified rubberized asphalt for sustainable road system: A focus on rubber particle size

Bio-modified rubberized asphalt (BMR) has been acclaimed for its superior pavement performance and eco-friendliness, which can promote the sustainability of road systems. However, its rheological properties, intimately tied to crumb rubber (CR) particle size, display variability during thermal storage. This study probed the effect of CR particle size on BMR's rheological attributes under thermal conditions. BMRs were prepared using varied CR particle sizes, thermally conditioned over a span of up to 10 h, and then tested for rheological properties. Our findings illustrate particle size's pivotal role in CR swelling, degradation, and asphalt aging mechanisms during thermal conditioning, consequently affecting various BMR characteristics. Large CR particles displayed slower swelling rates, with secondary swelling observed. The CR's micro-skeleton within asphalt phase amplified asphalt's elasticity recovery, causing an increased rutting factor and complex viscosity. In contrast, stress concentration due to CR particles curtailed the fatigue life of BMR. With smaller CR particles, both elastic response and viscosity of BMR diminished due to CR's devulcanization and depolymerization during thermal conditioning. However, substances released during CR degradation altered the asphalt composition, bolstering BMR's fatigue resistance. During thermal process, asphalt oxidation resulted in increased stiffness, thereby degrading BMR's rheological properties. It is beneficial for CR of 40 mesh or coarser to extend the breeding time to stabilize its performance, whereas for asphalt prepared with 60 mesh or finer CR, it should be used as soon as possible after preparation to prevent a significant performance degradation. In summary, managing particle size and thermal conditioning time is crucial in preserving BMR's optimal rheological properties.

Enhanced Light-Matter Interaction in Metallic Nanoparticles: A Generic Strategy of Smart Void Filling.

The intrinsic properties of materials play a substantial role in light-matter interactions, impacting both bulk metals and nanostructures. While plasmonic nanostructures exhibit strong interactions with photons via plasmon resonances, achieving efficient light absorption/scattering in other transition metals remains a challenge, impeding various applications related to optoelectronics, chemistry, and energy harvesting. Here, we propose a universal strategy to enhance light-matter interaction, through introducing voids onto the surface of metallic nanoparticles. This strategy spans nine metals including those traditionally considered optically inactive. The absorption cross section of void-filled nanoparticles surpasses the value of plasmonic (Ag/Au) counterparts with tunable resonance peaks across a broad spectral range. Notably, this enhancement is achieved under arbitrary polarizations and varied particle sizes and in the presence of geometric disorder, highlighting the universal adaptability. Our strategy holds promise for inspiring emerging devices in photocatalysis, bioimaging, optical sensing, and beyond, particularly when metals other than gold or silver are preferred.

Experimental Study on the Effect of Date Palm Powder on the Thermal and Physico-Mechanical Properties of Gypsum Mortars

Date palm leaves have been diachronically applied in building materials in the Middle East and North Africa (MENA) region, so as to enhance specific properties, such as volume stability and strength. This research work concerns an experimental study on the impact of date palm leaflet powder (DPLP) on the thermal and physico-mechanical properties of gypsum mortars. A series of mortar compositions were prepared with different proportions of DPLP (0, 1, 3, and 5% w/w of binder) and variant particle size (0.5, 1, and 1.5 mm). The results showed that the mortars containing DPLP exhibited significant changes in their properties due to variations in DPLP concentration and particle size. Increased DPLP led to lower density, higher porosity, and water absorption rate, whereas mechanical strength and thermal conductivity were decreased according to the DPLP proportion and size. This research provides valuable insights into the use of sustainable and renewable building materials, highlighting the benefits of exploiting agricultural waste in the constructional sector. The findings lay the groundwork for future research and innovation in environmentally friendly construction technologies.

Pore Water Conversion Characteristics during Methane Hydrate Formation: Insights from Low-Field Nuclear Magnetic Resonance (NMR) Measurements

Understanding the conversion characteristics of pore water is crucial for investigating the mechanism of hydrate accumulation; however, research in this area remains limited. This study conducted methane hydrate formation experiments in unconsolidated sands using an in-house low-field nuclear magnetic resonance (NMR) system. It focused on pore water conversion characteristics and influencing factors such as initial water saturation and sand particle sizes. Results show that methane hydrate formation enhances the homogeneity of the effective pore structure within sand samples. The conversion rate of pore water is significantly influenced by differences in heat and mass transfer capacity, decreasing as initial water saturation and sand size increase. Pore water cannot be fully converted into hydrates in unconsolidated sands. The final conversion ratio of pore water in water-poor sand samples nears 97%, while in water-rich sand samples, it is only 65.80%. Sand particle size variation has a negligible impact on the final conversion ratio of pore water, with ratios exceeding 94% across different particle sizes, differing by less than 3%.

Discrete element method study of the mixing and heat transfer behaviour of a binary‐size granular system in a rotating drum

AbstractUnderstanding the internal solid motion and heat transfer behaviour within rotating drums is paramount for their design and operation across various industries. The discrete element method (DEM) is utilized to elucidate the general flow, mixing, and heat transfer characteristics of particles within rotating drums. Following model validation, this study delves into the mixing behaviour and heat transfer patterns of binary‐size particles in the rotating drum, while also assessing the impact of size ratio and rotating speed. The findings reveal that variations in particle size result in noticeable radial segregation, consequently affecting the heat transfer dynamics of solid phase within the system. Higher rotating speeds enhance mixing and dispersion of solid phase but lead to a decrease in the averaged particle temperature. Furthermore, the heat flux exhibits a negative correlation with particle size. Distinct heat transfer behaviours are observed among particles of different sizes in both active and passive areas, with larger particle size ratios exacerbating segregation, potentially impacting final product quality. In summary, these findings offer crucial insights into heat transfer phenomena in rotating drums, aiding in the design and operation of apparatus.

Computational fluid dynamics method for determining the rotational diffusion coefficient of cells

This work presents a straightforward computational method to estimate the rotational diffusion coefficient (Dr) of cells and particles of various sizes using the continuum fluid mechanics theory. We calculate the torque (Γ) for cells and particles immersed in fluids to find the mobility coefficient μ and then obtain the Dr by substituting Γ in the Einstein relation. Geometries are constructed using triangular mesh, and the model is solved with computational fluid dynamics techniques. This method is less intensive and more efficient than the widely used models. We simulate eight different particle geometries and compare the results with previous literature.

Enhanced electrical, optical and magnetic properties of BiFeO3 perovskite nanoparticles co-doped with Y and Cu

The present work includes the fabrication of pure BiFeO3 and Bi0.9Y0.1Fe1−xCuxO3 (x = 0.05, 0.10, 0.15) nanoparticles by the usual sol-gel route. The characterization of structural, morphological, optical, electrical, and magnetic properties of the synthesized samples was achieved through x-ray diffraction spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, an impedance analyzer, and a vibrating sample magnetometer. The Fourier transform infrared study confirmed the presence of Bi–O and Fe–O bonds. The x-ray diffraction patterns confirmed the rhombohedral (R3c) structure as a major phase with the orthorhombic (Pnma) structure as a secondary phase in all samples, and few amount of impurity phase of Bi25FeO40 was also determined. The surface morphology analysis showed the variation of particle size from 63 to 174 nm. The Raman spectra of 13 optical phonon modes, including 4A1 and 9E symmetric phonons, are observed for all samples, and the positions of these modes are almost similar, except the intensities of A1 modes. The optical measurements show a reduction in bandgap from 2.17 to 2.03 eV with co-doping, revealing itself as a more promising applicant in photovoltaics. An enhanced value of the dielectric constant is observed for different doped samples at different frequency regions from 100 Hz to 10 MHz. Magnetic investigation demonstrates the improved ferromagnetism with co-doping of Y and Cu due to distortion in the FeO6 octahedron. A maximum saturation magnetization of 0.26 emu/gm and a coercivity of 2915 Oe were found for Y concentration of 10% and Cu concentration of 15%.

Lipolytic production from solid-state fermentation of the filamentous fungus Penicillium polonicum and its applicability as biocatalyst in the synthesis of ethyl oleate.

Lipases represent versatile biocatalysts extensively employed in transesterification reactions for ester production. Ethyl oleate holds significance in biodiesel production, serving as a sustainable alternative to petroleum-derived diesel. In this study, our goal was to prospect lipase and assess its efficacy as a biocatalyst for ethyl oleate synthesis. For quantitative analysis, a base medium supplemented with Rhodamine B, olive oil, and Tween 80 was used. Solid-state fermentation utilized crambe seeds of varying particle sizes and humidity levels as substrates. In the synthesis of ethyl oleate, molar ratios of 1:3, 1:6, and 1:9, along with a total enzymatic activity of 60 U in n-heptane, were utilized at temperatures of 30°C, 37°C, and 44°C. Reactions were conducted in a shaker at 200rpm for 60min. As a result, we first identified Penicillium polonicum and employed the method of solid-state fermentation using crambe seeds as a substrate to produce lipase. Our findings revealed heightened lipolytic activity (22.5 Ug-1) after 96h of fermentation using crambe cake as the substrate. Optimal results were achieved with crambe seeds at a granulometry of 0.6mm and a fermentation medium humidity of 60%. Additionally, electron microscopy suggested the immobilization of lipase in the substrate, enabling enzyme reuse for up to 4 cycles with 100% enzymatic activity. Subsequently, we conducted applicability tests of biocatalysts for ethyl oleate synthesis, optimizing parameters such as the acid/alcohol molar ratio, temperature, and reaction time. We attained 100% conversion within 30min at 37°C, and our results indicated that the molar ratio proportion did not significantly influence the outcome. These findings provide a methodological alternative for the utilization of biocatalysts in ethyl oleate synthesis.

New methods for the identification of malachite pigments with varying particle sizes used in ancient Chinese murals by spectroscopic techniques

This study attempts to propose a simple, low-interventive and higher accuracy identification method for malachite pigments with varying particle sizes based on attenuated total reflection-Fourier transform infrared (ATR-FTIR), and evaluate the accuracy of ATR-FTIR and ultraviolet–visible near-infrared (UV-VIS-NIR) spectroscopy for identifying particle sizes. The micro-morphology, particle size, colour difference, and spectral characteristics of the malachite samples were determined using scanning electron microscopy (SEM), laser particle size analysis, colourimetry, UV-VIS-NIR and ATR-FTIR spectrometry. The principal component analysis (PCA) and mathematical models based on nonlinear curve fitting using UV-VIS-NIR and FTIR spectral data were developed and evaluated for the particle size identification of various malachite samples (pure malachite samples, fresh and aged malachite-rabbit glue samples). SEM morphological results showed that the malachite pigments with smaller particle sizes appear to have irregular flakes with a few loose agglomerated granules attached to the surface. The weight-specific surface area also increased gradually as the pigment particle size decreased. The colour difference results revealed that smaller malachite particle size gradually shifted toward the red–blue regions in CIE L*a*b* colour space. In addition, more intense reflectance and IR spectral absorbance peaks were observed in the case of the smaller particle size. The above proposed methods of particle size identification proved to be highly feasible and effective in predicting pigment particle size, which were confirmed by the PCA identification results and the mathematical model. Also, ATR-FTIR spectroscopy could provide more accurate predictions than UV-VIS-NIR spectroscopy, by keeping prediction errors below 5.5 μm.

Synthesis of TiCx/Al Composites via In Situ Reaction between AlxTi Melt and Dissolvable Solid Carbon

TiCx/Al composites were successfully prepared in this study by dissolving graphite particles in Al-Ti melt based on the principle of a solid–liquid in situ reaction. It was observed that the microstructure of the TiCx/Al composites changed with changes in the reaction temperature and graphite particle size. With an increase in reaction temperature, the TiCx particles in the TiCx/Al composites transitioned from a spider-like distribution to being evenly dispersed in the Al matrix. Additionally, the morphology of the TiCx particles changed from polygons of various sizes to quasi-spherical shapes with a uniform particle size, while the presence of Al4C3 and Al3Ti in the matrix diminished. The size variation of the graphite particles had minimal impact on the particle size and stoichiometric ratio of TiCx generated in the sample. Furthermore, an appropriate graphite particle size was found to mitigate the agglomeration and residue of graphite particles during the in situ reaction.