Preparation Of Particles Research Articles

Preparation of high-purity dispersed single-crystal diamond particles

Preparation of high-purity dispersed single-crystal diamond particles

Preparation of CeO2 particles via Ionothermal Synthesis and its Application to Chemical Mechanical Polishing

Preparation of CeO2 particles via Ionothermal Synthesis and its Application to Chemical Mechanical Polishing

Preparation of mono-sized high sphericity Al-Si alloy particles for thermal energy storage materials by pulsated orifice ejection method

The demand for Al-Si particles with high sphericity and narrow size distribution is growing in the field of thermal energy storage. In this study, a novel pulsated orifice ejection method (POEM) was successfully employed to produce different-sized Al-Si alloy particles. The analysis indicates that such particles exhibit high sphericity, with each particle having a sphericity exceeding 0.9. The particles are precisely size-controllable and mono-sized, thereby ensuring that they have the identical thermal history. The combination of cooling rate calculation and particle structure analysis indicates that the particles prepared by POEM exhibit higher cooling rates through rapid solidification, resulting in finer and more uniform microstructures. The thermal analysis results demonstrate that the Al-Si alloy particles prepared in this study have high melting latent heat (approximately 500.87 J/g) and solidification latent heat (approximately 467.26 J/g), showcasing their potential as high-efficiency phase change materials for high-temperature thermal energy storage.

Insight into low-grade natural Linze palygorskite for composite particles preparation towards efficient wastewater treatment

Natural clay possesses advantages such as low cost and high adsorption capacity, rendering it a promising adsorbent for wastewater treatment. In this work, low-grade Linze palygorskite (LZ), comprising 20.5% palygorskite, was utilized as a representative material to synthesize polyvinylformal-LZ (PVFM-LZ) composite particles through cross-linking polyvinyl alcohol (PVA) with formaldehyde. The raw material ratio of LZ and PVA was maintained at a high level of 20:1. Meanwhile, high-purity montmorillonite (Mt) and palygorskite (Pal) were employed as raw materials to prepare PVFM-Mt and PVFM-Pal using the same method, enabling comparative analysis with PVFM-LZ. PVFM-LZ exhibited a notable adsorption capacity of 101.92 mg·g−1 for methylene blue, which was comparable to that of PVFM-Mt and PVFM-Pal. What’s more, owing to the tightly cross-linked network structure formed by PVFM, PVFM-LZ demonstrated minimal loss (2.53%) and swelling (8.0%) rates in water, facilitating easy separation and promoting recyclability. Even after six cycles, its adsorption efficiency remained above 85%. The structure, physicochemical properties and adsorption performance of the three composite particles were meticulously examined before and after adsorption. Kinetic, thermodynamic and isotherm adsorption models revealed that PVFM-LZ exhibited spontaneous surface-controlled monolayer adsorption behavior. The possible adsorption mechanisms included electrostatic interactions, hydrogen bonding, and intermolecular forces. This work may provide an experience for the adsorption application of low-grade natural clay in composite engineering.

Design and preparation of spherical particles in water via thermal-induced liquid-liquid phase separation and a molecular mechanism study

In the pharmaceutical and fine chemical industries, spherical particles are highly valuable due to their numerous applications; however, they are hindered by traditional methods requiring intricate devices, high energy consumption, and biohazardous solvents. In this study, we constructed a strategy for the design of spherical particles based on thermal-induced liquid–liquid phase separation at the microscopic molecular level. Based on this strategy, high-performance spherical particles were successfully prepared in water by a simple heating-quenching operation. Moreover, this strategy could also control the solid structure of particles by utilizing intermolecular interactions to meet the requirements of various application scenarios. In the case of fenofibrate, the equipment was simplified, the use of organic solvents was avoided, and the powder properties, filtration properties, and tableting performance of the product were significantly enhanced compared to those reported literature. This work elucidated the design and green production of new crystalline/amorphous materials with versatile functions.

Polymer Characteristics for Drug Layering on Particles Using a Novel Melt Granulation Technology, MALCORE®.

MALCORE®, a novel manufacturing technology for drug-containing particles (DCPs), relies on the melt granulation method to produce spherical particles with high drug content. The crucial aspect of particle preparation through MALCORE® involves utilizing polymers that dissolve in the melt component, thereby enhancing viscosity upon heating. However, only aminoalkyl methacrylate copolymer E (AMCE) has been previously utilized. Therefore, this study aims to discover other polymers and comprehend the essential properties these polymers need to possess. The results showed that polyvinylpyrrolidone (PVP) was soluble in the stearic acid (SA) melt component. FTIR examination revealed no interaction between SA and polymer. The phase diagram was used to analyze the state of the SA and polymer mixture during heating. It revealed the mixing ratio and temperature range where the mixture remained in a liquid state. The viscosity of the mixture depended on the quantity and molecular weight of the polymer dissolved in SA. Furthermore, the DCPs prepared using PVP via MALCORE® exhibited similar pharmaceutical properties to those prepared with AMCE. In conclusion, understanding the properties required for polymers in the melt granulation process of MALCORE® allows for the optimization of manufacturing conditions, such as temperature and mixing ratios, for efficient and consistent drug layering.

Kinetically Controlled Polyelectrolyte Complex Assembly of microRNA-Peptide Nanoparticles toward Treating Mesothelioma.

Broad size distributions and poor long-term colloidal stability of microRNA-carrying nanoparticles, especially those formed by polyelectrolyte complexation, represent major hurdles in realizing their clinical translation. Herein, peptide design is used alongside optimized flash nanocomplexation (FNC) to produce uniform peptide-based miRNA particles of exceptional stability that display anticancer activity against mesothelioma in vitro and in vivo. Modulating the content and display of lysine-based charge from small intrinsically disordered peptides used to complex miRNA proves essential in achieving stable colloids. FNC facilitates kinetic isolation of the mechanistic steps involved in particle formation to allow the preparation of particles of discrete size in a highly reproducible, scalable, and continuous manner, facilitating pre-clinical studies. To the best of the authors knowledge, this work represents the first example of employing FNC to prepare polyelectrolyte complexes of miRNA and peptide. Encapsulation of these particles into an injectable hydrogel matrix allows for their localized in vivo delivery by syringe. A one-time injection of a gel containing particles composed of miRNA-215-5p and the peptide PKM1 limits tumor progression in a xenograft model of mesothelioma.

The role of biocompatible coatings of magnetic nanorods on their thermal response in hyperthermia. Consequences on tumor cell survival

There are so many hopes for nanoscience as a tool in the fight against various diseases, notably cancer, that the problem can be approached from many different points of view. In this paper, we focus on two essential aspects. One is the preparation of non-spherical and superparamagnetic magnetic particles, with the right size to be able to exit the blood vessels and be incorporated by cells. The second is their use as agents of hyperthermia. For the first purpose, a two-step method was followed, in which hematite templates with the desired shape and size were first prepared, and these were subsequently reduced by heat treatment. As a result, nanorods with a length of 40 nm and an axis ratio of 1:8 were obtained. The bare particles were coated with a triple layer of cationic/anionic/cationic polymers. Electrophoretic mobility, thermogravimetric analysis, x-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy evaluations confirmed the presence of the coating and the positive charge of the last polymeric layer, while x-ray diffraction and micro-Raman spectroscopy indicated that the crystal structure of the core particles was magnetite/maghemite. The magnetization cycles of the particles showed that they were superparamagnetic, with a saturation magnetization of 82 emu/g in the case of the bare particles. For concentrations up to 300 μg/mL, they were found to be compatible with MCF7 (Michigan Cancer Foundation-7) breast cancer cell line, for cell uptakes higher than 80 %. Both bare and polymer-coated particles produced heating by magnetic hyperthermia and laser-light irradiation. Finally, cytotoxicity against the cancer cells was evaluated, and it was found that photothermia and, above all, magnetic hyperthermia applied to the coated particles could induce more than 50% cell death.

Study on bulletproof performance of functionalized fabrics modified by microcapsules

AbstractThe incorporation of microcapsule particles (MPs) into fabrics offers the potential to enhance both the friction between fabric yarns and the bulletproof impact performance. In this study, MPs were prepared using the interfacial polymerization method. Furthermore, an innovative modification of the AF fabric was achieved by introducing a silane coupling agent and MPs. This resulted in the development of a microcapsules‐aramid fibers (MPs‐AF) composite material exhibiting excellent protective performance. The characterization experiment demonstrated the successful adhesion of MPs to the AF fabric, forming a robust bond between the fiber and the particles. Importantly, the modification process did not have any adverse effects on the fiber structure. The study further investigated the ballistic performance and protection mechanism of the modified fabrics through mechanical performance tests and ballistic impact tests. The yarn pull‐out experiment revealed that the MPs‐AF composite material exhibited a significant increase in pull‐out force, with a remarkable improvement of 175.6% compared to AF fabric. In the ballistic impact experiments, the MPs‐AF composite material demonstrated a substantial increase in ballistic limit velocity, rising from 52 to 118 m/s when compared to the AF fabric. These findings highlight the potential application of the MPs‐AF composite material in the field of wearable protection.Highlights Fiber surface modification grafting reaction. A simple and novel solution impregnation method was used to prepare modified AF. Preparation of microcapsule particles by interfacial polymerization. Green new fiber bulletproof material. Chemical grafting produces strong chemical bonds to increase interfacial resistance.

Antisolvent precipitation for the synergistic preparation of ultrafine particles of nobiletin under ultrasonication-homogenization and evaluation of the inhibitory effects of α-glucosidase and porcine pancreatic lipase in vitro

To further enhance the application of nobiletin (an important active ingredient in Citrus fruits), we used ultrasonic homogenization-assisted antisolvent precipitation to create ultrafine particles of nobiletin (UPN). DMSO was used as the solvent, and deionized water was used as the antisolvent. When ultrasonication (670 W) and homogenization (16000 r/min) were synergistic, the solution concentration was 57 mg/mL, and the minimum particle size of UPN was 521.02 nm. The UPN samples outperformed the RN samples in terms of the inhibition of porcine pancreatic lipase, which was inhibited (by 500 mg/mL) by 68.41 % in the raw sample, 90.34 % in the ultrafine sample, and 83.59 % in the positive control, according to the data. Fourier transform infrared spectroscopy analysis revealed no chemical changes in the samples before or after preparation. However, the crystallinity of the processed ultrafine nobiletin particles decreased. Thus, this work offers significant relevance for applications in the realm of food chemistry and indirectly illustrates the expanded application potential of nobiletin.

Preparation of graphene-coated Cu particles with oxidation resistance by flash joule heating

Cu particles are limited in their applications due to their susceptibility to oxidation. Here we report a cost-effective method for producing Cu particles with oxidation resistance. By heating the mixture of basic cupric carbonate and glucose powders, Cu particles coated with amorphous carbon were achieved. The amorphous carbon was then converted into graphene through flash joule heating (FJH). The conductivity of the final product was 47.1 S/cm after FJH, which remained as 42.3 S/cm even after in hot air for 30 min, i.e., 89.8% conductivity retention. The product was demonstrated for the application of electromagnetic interference (EMI) shielding with an average EMI shielding effectiveness of 12.3 dB and 11.7 dB before and after oxidizing treatment, respectively.

Preparation and Adsorption Properties of Polymer Particles based on N, N, N', N'-Tetrakis(4-aminophenyl)-1,4-Benzenediamine

Abstract: Two polymer particles have been prepared by the reaction of N, N, N', N'-tetrakis(4- aminophenyl)-1,4-benzenediamine, 4, 4-biphenyldialdehyde and isophthalaldehyde, and characterized by SEM, FTIR and XRD. Based on methylene blue as the model pollutant, the adsorption properties of two polymer particles have been observed by using different adsorbent dosages, adsorption times and adsorption temperatures. Experimental data show that the removal rates of methylene blue wastewater are 74 % for polymer A and 68 % for polymer B, and the removal rates are up to 84% for polymer A and 74 % for polymer B after photo-catalytic treatment. All these suggest that the adsorption performance of polymer A is more excellent than that of polymer B. In addition, the methylene blue adsorption of the two Schiff base products conforms to the Freundlich adsorption isothermal model.

Superhydrophilic and superhydrophobic quartz sand hybrid filters for efficient on-demand oil/water separation

The development of an efficient and sustainable separation method for oily wastewater has become a major challenge for industrial development and environmental protection. In this work, the simple special wettability particle preparation method and the hybrid filters construction strategy was reported for enhanced oil/water separation efficiency. Two special wettability quartz sands mixed in a certain proportion could destroy the balance of dispersed droplets in the oil-water emulsion, induce the coalescence of dispersed droplets, and purify the oil-water emulsion by the tortuous channel in the filter. Based on the coupling effect of “size sieving” and “coalescence separation”, the special wettability particle hybrid filter with a mass ratio of 3:1 had good droplet coalescence ability, and the separation efficiency of various kinds of oil-water emulsions can reached more than 98%. The hybrid filters exhibited robust mechanical and chemical stability, excellent durability, which enable them to be competent for oil/water separation in multitasking and complex environment.

Ultra-stable pickering emulsion stabilized by anisotropic pea protein isolate-fucoidan conjugate particles through Maillard reaction

Bio-based emulsifiers hold significant importance in various industries, particularly in food, cosmetics, pharmaceuticals and other related fields. In this study, pea protein isolate (PPI) and fucoidan (FUD) were conjugated via the Maillard reaction, which is considered safe and widely used in the preparation of food particle. The PPI-FUD conjugated particles exhibit an anisotropic non-spherical structure, thereby possessing a high detachment energy capable of preventing emulsion coalescence and Ostwald ripening. Compared to emulsions previously prepared in other studies (< 500 mM), the Pickering emulsion stabilized by PPI-FUD conjugate particles demonstrates outstanding ionic strength resistance (up to 5000 mM). Furthermore, when encapsulating curcumin, the Pickering emulsion protects the curcumin from oxidation. Additionally, the formulated emulsions demonstrated the capability to incorporate up to 60 % (v/v) oil phase, revealing remarkable performance in terms of storage stability, pH stability, and thermal stability.

Recent progresses on Janus electrocatalysts for water electrolysis: A critical review

Newly emerged Janus materials showed the vast potential for catalysis and photocatalysis owing to their multifunctional properties, attracting attention as next-generation functional materials. This Review focuses on various synthesis processes for developing a novel class of Janus materials for applications in electrocatalysis and photo-electrocatalysis via water electrolysis. Starting with summarizing the different designs and preparation of Janus particles, this Review analyzed the compositions and categories of Janus materials. Furthermore, this Review discusses various synthesis processes of Janus materials, followed by classifications of different synthesis routes for Janus materials with a detailed review of the respective process parameters, multifunctional properties, and present status of their development. This Review also summarizes the comprehensive properties of the Janus material, subjected to their applications toward catalytic hydrogen evolution reactions, oxygen evolution reactions, and photo-electrocatalysis. Finally, a thorough summary is presented on the synthesis and applications of Janus particle, while the respective challenges and outlooks are also discussed.

Enhancing Antimicrobial Efficacy and Synergistic Effects of Nano-Silica-Based Combinations With Doxycycline, Metronidazole, and Ciprofloxacin Against Enterococcus faecalis Biofilms.

Enterococcus faecalisbiofilm formation within root canals poses a challenging problem in endodontics, often leading to treatment failure. To combat this issue, nanotechnology offers a promising avenue for enhancing antimicrobial efficacy. This study explores the potential synergistic effects of combining nanoscale silica particles with conventional antibiotics, including doxycycline, metronidazole, and ciprofloxacin, against E. faecalis biofilms. The unique characteristics of silica nanoparticles, such as their increased reactivity and ability to be functionalized with other compounds, make them ideal candidates for augmenting antibiotic efficacy. This research investigates the antimicrobial properties of these silica-based combinations and their potential to eliminate or inhibit E. faecalis biofilms more effectively than conventional treatments. Methodology: The methods involved the preparation of nanostructured silica particles and their combination with doxycycline, Flagyl, and ciprofloxacin at subinhibitory concentrations. These combinations were then tested against E. faecalis biofilms using the agar well diffusion technique. Preliminary results suggested that the synergistic interactions between silica nanoparticles and antibiotics can significantly enhance antimicrobial efficacy. The combined treatment exhibited superior inhibitory effects on E. faecalis compared to antibiotics or silica nanoparticles alone (P< 0.05). Conclusions: This study sheds light on the potential of nanoscale silica-based combinations to address the challenges posed by E. faecalis biofilms in endodontics. Understanding the mechanisms of synergy between nanoparticles and antibiotics can pave the way for the development of more effective and targeted strategies for root canal disinfection, ultimately improving the success rates of endodontic treatments.

[Preparation of Nanoplastic Particles as Potential Standards for the Study of Nanoplastics].

Nanoplastics (NPs) are plastic fragments that are small enough to be absorbed by organisms through ingestion or inhalation. Recent studies indicate that nanoplastics can be ubiquitous in the environment, and there are growing concerns regarding the impacts of nanoplastics on the health of humans and other organisms. However, quantitative information on nanoplastics in the environment is still very limited, and most previous toxicity studies have used only polystyrene (PS) particles because of a lack of appropriate model particles of other plastics. We developed a nanoprecipitation-based method for the preparation of nanoplastic particles of five major polymers: low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), and polystyrene. A major advantage of our method is that the nanoplastic particles are prepared without using reagents that can remain in the particles as impurities. Analysis of the prepared particles' molecular weight (Mw) distributions, crystallinities, and thermal properties revealed that their compositions and constitutions were within the general ranges for commercial products. The mechanisms underlying the formation of low-density polyethylene particles via our method were investigated by means of a simple population balance model, and particle diameter was found to be linearly correlated with the suspension density of the nanoplastic dispersion up to 0.4 mg·mL-1. Future studies should focus on improving our method to allow for precise, scale-independent production of nanoplastic particles. Methods for the preparation of labeled particles are also needed so that such particles can be used in nanoplastic risk assessments.

Preparation of hollow silica particles by template method via chemical vapor deposition

Preparation of hollow silica particles by template method via chemical vapor deposition

Effect of Mineral Powders on the Properties of Foam Concrete Prepared by Cationic and Anionic Surfactants as Foaming Agents.

Foam concrete is a type of cement mortar in which air bubbles are introduced using an appropriate foaming agent. The complex conditions for the preparation of solid particle stabilized foams limit their wide application in construction. In this study, a method of adding small amounts of calcite (Cal) and muscovite (Mus) to the cement paste matrix is proposed to improve the properties of foam concrete prepared with cationic and anionic surfactants as foaming agents. The effects of mineral powders on the flowability, compressive strength, water absorption, pore characteristics, thermal conductivity and frost resistance of foam concrete were investigated and the enhancement mechanism was revealed by the results of XRD, low-field nuclear magnetic resonance (LF-NMR), Fourier transform infrared spectroscopy (FTIR) and SEM. The results showed that the mineral powders interacted with anionic and cationic surfactants through physical adsorption. Whether anionic or cationic surfactants were used as foaming agents, the addition of mineral powders promoted the formation of shell-like structures around the foam, thus enhancing the performance of foam concrete. As a result, the fluidity, compressive strength and frost resistance of the foam concrete increased, the water absorption and thermal conductivity decreased, and the average size of the pores decreased.

Cell Staining Microgels Derived from a Natural Phenolic Dye: Hematoxylin Has Intriguing Biomedical Potential.

Hematoxylin (HT) as a natural phenolic dye compound is generally used together with eosin (E) dye as H&E in the histological staining of tissues. Here, we report for the first time the polymeric particle preparation from HT as poly(Hematoxylin) ((p(HT)) microgels via microemulsion method in a one-step using a benign crosslinker, glycerol diglycidyl ether (GDE). P(HT) microgels are about 10 µm and spherical in shape with a zeta potential value of -34.6 ± 2.8 mV and an isoelectric point (IEP) of pH 1.79. Interestingly, fluorescence properties of HT molecules were retained upon microgel formation, e.g., the fluorescence emission intensity of p(HT) at 343 nm was about 2.8 times less than that of the HT molecule at λex: 300 nm. P(HT) microgels are hydrolytically degradable and can be controlled by using an amount of crosslinker, GDE, e.g., about 40%, 20%, and 10% of p(HT) microgels was degraded in 15 days in aqueous environments for the microgels prepared at 100, 200, and 300% mole ratios of GDE to HT, respectively. Interestingly, HT molecules at 1000 mg/mL showed 22.7 + 0.4% cell viability whereas the p(HT) microgels exhibited a cell viability of 94.3 + 7.2% against fibroblast cells. Furthermore, even at 2000 mg/mL concentrations of HT and p(HT), the inhibition% of α-glucosidase enzyme were measured as 93.2 ± 0.3 and 81.3 ± 6.3%, respectively at a 0.03 unit/mL enzyme concentration, establishing some potential application of p(HT) microgels for neurogenerative diseases. Moreover, p(HT) microgels showed two times higher MBC values than HT molecules, e.g., 5.0 versus 2.5 mg/mL MIC values against Gram-negative E. coli and Gram-positive S. aureus, respectively.