Submicron-sized Particles Research Articles

Crystal structure of submicron-sized sulfur particles using 3D ED obtained in atmospheric conditions.

Lithium-sulfur batteries are a promising candidate for the next generation of rechargeable batteries. Despite extensive research on this system over the last decade, a complete understanding of the phase transformations has remained elusive. Conventional in-situ powder X-ray diffraction has struggled to determine the unit cell and space group of the polysulfides formed during charge and discharge cycles due to the high solubility of these solid products in the liquid electrolyte. With the improvement in in-situ electrochemical set-ups dedicated to transmission electron microscopes, three-dimensional electron diffraction (3D ED) has the potential to capture the crystal structures of the polysulfides during cycling. In this work, the structure solution and refinement from 3D ED data of elemental sulfur, known to sublimate in the vacuum of transmission electron microscopes, is enabled through the use of an environmental cell with a micro-electromechanical system. This work represents the first step in characterizing sulfur's transformation into lithium polysulfides using in-situ 3D ED.

Nanosuspension Innovations: Expanding Horizons in Drug Delivery Techniques.

Nanosuspensions (NS), with their submicron particle sizes and unique physicochemical properties, provide a versatile solution for enhancing the administration of medications that are not highly soluble in water or lipids. This review highlights recent advancements, future prospects, and challenges in NS-based drug delivery, particularly for oral, ocular, transdermal, pulmonary, and parenteral routes. The conversion of oral NS into powders, pellets, granules, tablets, and capsules, and their incorporation into film dosage forms to address stability concerns is thoroughly reviewed. This article summarizes key stabilizers, polymers, surfactants, and excipients used in NS formulations, along with ongoing clinical trials and recent patents. Furthermore, a comprehensive analysis of various methods for NS preparation is provided. This article also explores various in vitro and in vivo characterization techniques, as well as scale-down technologies and bottom-up methods for NS preparation. Selected examples of commercial NS drug products are discussed. Rapid advances in the field of NS could resolve issues related to permeability-limited absorption and hepatic first-pass metabolism, offering promise for medications based on proteins and peptides. The evolution of novel stabilizers is essential to overcome the current limitations in NS formulations, enhancing their stability, bioavailability, targeting ability, and safety profile, which ultimately accelerates their clinical application and commercialization.

Wear Resistance of Nickel Composite Coatings with Micron-Sized and Submicron-Sized Particles of SiC

Introduction. Electrolytic deposition of nanoparticles is gaining interest with their increasing demand for restoring surface layers of machine parts and mechanisms. To create composite coatings with nanoparticles, it is necessary to solve two main tasks: to ensure a sufficient number of particles in the coating and to prevent their agglomeration in the coating solutions.These coatings with nanoparticles are wear-resistant and are used, for example, in automobile and tractor engines. In this study, there are considered the process of electrolytic production of composite coatings based on a nickel matrix with micron-sized and submicron-sized silicon carbide (SiC) particles from Watts nickel solutions and the resistance of nickel composite coatings to sliding wear.Aim of the Study. The study is aimed at considering detailed the effect of the size and number of particles in the coating solution on the number of codeposed particles. It is also necessary to study how the particle size affects the codeposition of micron-sized and submicron-sized particles of the non-Brownian type.Materials and Methods. A conventional nickel-plating electrolyte was used for nickel-based composite coatings with SiC. There was measured particle number density for each coating solution. It was assumed that the particles had the same size and shape of a sphere. The concentration of particles in the coating solutions ranged from 0.28 to 104 g/l. Electrodeposition was carried out on vertical electrodes, and the coating solution was stirred with a magnetic stirrer during electrodeposition. The Vickers microhardness with a load of 30 g was measured and wear tests were performed for unidirectional and bidirectional sliding.Results. The results of studying the wear resistance of nickel composite coatings during sliding have been obtained. The results of codeposition and a model based on the density of codeposed particles are presented. There has been made the conclusion about effect of codeposed particles on the wear resistance of Ni-SiC composite coatings.Discussion and Conclusion. It was determined that the best sliding resistance was obtained using Ni-SiC composite coatings containing 4–5 volume percentage of submicron-sized SiC particles. The study showed that the size and density of SiC particles in the coating solution are important for producing galvanically wear-resistant composite coatings, based on the relationship between the density of deposited particles and the density of particles in solutions.

Bioactive potency of extracts from Stylissa carteri and Amphimedon chloros with silver nanoparticles against cancer cell lines and pathogenic bacteria.

Silver nanoparticles (AgNPs) are spherical particles with a number of specific and unique physical (such as surface plasmon resonance, high electrical conductivity and thermal stability) as well as chemical (including antimicrobial activity, catalytic efficiency and the ability to form conjugates with biomolecules) properties. These properties allow AgNPs to exhibit desired interactions with the biological system and make them prospective candidates for use in antibacterial and anticancer activities. AgNPs have a quenching capacity, which produces reactive oxygen species and disrupts cellular processes (such as reducing the function of the mitochondria, damaging the cell membrane, inhibiting DNA replication and altering protein synthesis). In addition, sponge extracts contain biologically active substances with therapeutic effects. Therefore, the concurrent use of these agents may present a potential for the development of novel antitumor and antimicrobial drugs. The present study investigated the cytotoxic effects of AgNPs combined with the extracts from sponge species, Stylissa carteri or Amphimedon chloros, against various cancer cell lines and pathogenic bacterial strains. The present study was novel as it provided a further understanding of the cytotoxicity and underlying mechanisms of AgNPs. Alterations in the properties, such as size, charge and polydispersity index, of the AgNPs were demonstrated after lyophilization. Scanning electron microscopy revealed submicron-sized particles. The cytotoxic potential of AgNPs across various cancer cell lines such as lung, colorectal, breast and pancreatic cancer cell lines, was demonstrated, especially when the AgNPs were combined with sponge extracts, which suggested a synergistic effect. Analysis using liquid chromatography-mass spectrometry revealed key chemical components in the extracts, and molecular docking simulations indicated potential inhibition interactions between a number of the extract components and the epidermal growth factor receptor and tyrosine kinase receptor A. Synergistic antibacterial effects against several bacterial species such as Staphylococcus xylosus, Klebsiella oxytoca, Enterobacter aerogenes, Micrococcus spp. and Escherichia coli, were observed when AgNPs were combined with sponge ethyl acetate extracts. The results of the present study suggested a potential therapeutic application of marine-derived compounds and nanotechnology in combating cancer and bacterial infections. Future research should further elucidate the mechanistic pathways and investigate the in vivo therapeutic efficacy.

A long straight square microchannel in viscoelastic fluid for focusing submicron-sized particles and bacteria.

Aviscoelastic flow focusing device is presentedthat enables simple and robust focusing of submicron-sized particles in the channel center by optimizing operating conditions such as channel length, flow rate and poly(ethylene oxide) (PEO) concentration. Submicron-sized particles (up to 100nm) can be easily focused to the channel center under viscoelastic fluid flow without any external force via a simply fabricated microchannel with a long channel length and a large square cross-section. The device was fabricated using a common soft lithography technique for the polydimethylsiloxane (PDMS) channel, which has a width of 50μm, a height of 50μm and a channel length of 27cm. The extralong channel enabled submicron-sized particle focusing, even in a channel of a relatively large size with high flow rate, which can realize flow cytometric applications. The focusing performance was first demonstrated using submicron-sized polystyrene (PS) beads ranging from 870nm to 50nm and then using biological particles such as E. coli bacteria to demonstrate the biological feasibility of the device. The PS beads, which ranged in diameter from 870nm to 100nm, were focused to the center of the channel, achieving over 90% focusing efficiency for beads as small as 510nm and 62% focusing efficiency for 100-nm beads. The device could also align a bacterial suspension in the center of the channel at flow rates up to 30 µL/min, demonstrating its biological importance. The ability of the developed device to align submicron-sized particles within a narrow flow stream in a highly robust manner is promising for various biological and clinical applications, such as distinguishing pathogenic bacteria and evaluating individual antibiotic responses in a single experiment.

Tribological behavior of hybrid Aluminum-TiB2 metal matrix composites for brake rotor applications

This research investigates the feasibility of hybrid aluminum metal matrix composites (MMC) incorporating TiB2 particles for brake rotor applications. The composites were produced by incorporating both in-situ, submicron-sized TiB2 particles and regular micron-sized TiB2 powders via stir and squeeze casting techniques into A206 aluminum alloy matrix. Systematic adjustments in the fractions of in-situ and ex-situ TiB2 particles were conducted to evaluate their impact on wear behavior and mechanisms. Combination of both particle types allowed composites with up to 10 vol% of reinforcements. Composites with higher proportions of ex-situ particles demonstrated increased wear resistance compared to those solely composed of in-situ particles, control specimens without TiB2, and conventional cast iron counterparts. The lowest wear rate for the hybrid composites sliding against phenolic brake pads was 1.1 × 10−5 mm3/Nm, signifying a 3-fold reduction relative to cast iron sliding against the same pads. Wear analysis elucidated distinctive mechanisms within the hybrid composites, characterized by mild fragmented abrasive wear, adhesive wear, and plastic deformation, accompanied by the formation of an intermixed tribo-oxide layer.

Innovative use of lipid mesophase dispersions for bisphenol A sequestration in water

HypothesisMesophase dispersions are promising colloids for removing micropollutants from water. We hypothesized that the complex internal nanostructure and tunable lipid/water interface amounts play a crucial role in absorbed quantities. Modifications in interfacial organization within the particles while trapping the micropollutant is assumed. ExperimentsWe formulated stable monolinolein-based dispersions with four types of mesophases (bicontinuous and micellar cubic, hexagonal, and fluid isotropic L2) by varying dodecane contents. The absorption of bisphenol A by these dispersions from water was monitored using molecular spectroscopy. At equilibrium, absorbed quantities by mesophase dispersions were compared to unstructured dodecane/water miniemulsions for two bisphenol concentrations. Structural changes during bisphenol incorporation were identified using small-angle X-ray scattering. FindingsLipid mesophase particles of submicron size showed greater bisphenol incorporation than dodecane/water miniemulsions, with cubosomes being most effective ones, absorbing twice as much as unstructured emulsions. Higher absorption levels are observed for more complex nanostructures with increased lipid/dodecane ratios. The incorporation of bisphenol affected the curvature of internal interfaces, potentially causing phase transitions and indicating that bisphenol settles at interfaces. Similar absorption levels in identical mesophases suggest a strong correlation between nano-structure and absorbed quantities.

Comprehensive Characterization of Bi1.34Fe0.66Nb1.34O6.35 Ceramics: Structural, Morphological, Electrical, and Magnetic Properties

Recent research in solid-state physics and materials engineering focuses on the development of new dielectric materials, with bismuth-based pyrochlores being already extensively applied in communications technology for their excellent dielectric properties and relatively low sintering temperatures. Herein, the structural, morphological, electrical, and magnetic properties of Bi1.34Fe0.66Nb1.34O6.35 ceramic, prepared by the sol–gel method and sintered at 500 °C, are investigated. The Rietveld refinement of the XRD pattern showed a cubic phase belonging to the space group Fd-3m and a crystallite size of 42 nm. Transmission electron microscopy further confirmed the crystallite size and the homogeneous distribution of Bi, Fe, Nb, and O elements, as evidenced by high-angle annular dark field imaging and STEM-EDX mapping. The morphology of the sample, assessed by scanning electron microscopy, is characterized by submicron-sized spherical particles. Dielectric spectroscopic studies revealed that the dielectric properties, strongly influenced by frequency and temperature, indicate the material’s potential for energy storage due to lower dielectric loss compared to the dielectric constant. The observed relaxation phenomena, confirmed through variations in dielectric loss and loss tangent, highlight the influence of grain boundaries and temperature on electron hopping and charge carrier dynamics. Using SQUID magnetometry, we identified two distinct magnetic phases. The primary phase, corresponding to the Bi1.34Fe0.66Nb1.34O6.35 ceramic, exhibits an antiferromagnetic behavior below its Néel temperature at around 8.8 K. A secondary high-Curie temperature ferrimagnetic phase, likely vestigial maghemite and/or magnetite, was also detected, indicating an estimated fraction below 0.02 wt.%.

Sol-gel synthesis, structure and adsorption properties of LiMgxMn(2-x)O4 (0 ≤ x ≤ 0.7) Oxides

Lithium manganese оxides with a spinel structure LiMgxMn(2–x)O4, doped with Mg2+ ions in the range 0 ≤ x ≤ 0.7, were obtained by sol-gel synthesis. Phase composition and morphology of obtained оxides were studied by using X-ray phase analysis and scanning electron microscopy. It is shown, that in the studied range 0 ≤ x ≤ 0.7 Mg-doped lithium manganese оxides saved the structure of the original cubic spinel LiMn2O4, while an increase in parameter a was observed from 8.175 to 8.309 Å and average crystallite size practically unchanged (30–36 nm). Samples of the initial LiMn2O4 and Mg-doped spinels were represented by prismatic particles of submicron (0.1–0.2 µm) and micron (1.0–3.0 µm) sizes, respectively. The effect of the adsorbent dose (0.05–0.3 g/l) and pH (3.0–13.0) of the solution on the adsorption efficiency was studied. The adsorption isotherms of the LiMg0.3Mn1.7O4 samples were described by the Langmuir monomolecular adsorption equation. An increase in the temperature of the model solution from 25 to 45°C was accompanied by an increase in the maximum adsorption of the LiMg0.3Mn1.7O4 samples from 10.50 to 10.98 mmol/g, which indicates the endothermic nature of the adsorption process. The kinetics of adsorption was well described by a pseudo-second order equation, which indicates the occurrence of chemical interaction during the adsorption process.

Fully Atom-Efficient Solvent-Mediated Biopolymer Manufacturing: A Base Case Illustrated with Macromolecular Surfactants Tailored to Stable Polymer-Water Interfaces.

This work introduces a novel 1-pot, 0-waste, 0-VOC methodology for synthesizing polymeric surfactants using acrylated epoxidized soybean oil and acrylated glycerol as primary monomers. These macromolecular surfactants are synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, allowing for tunable hydrophilic-lipophilic balance (HLB) and ionic properties. We characterize the copolymers' chemical composition and surface-active properties, and evaluate their effectiveness in forming and stabilizing emulsions of semiepoxidized soybean oil and poly(acrylated epoxidized high oleic soybean oil). Comprehensive analyses, including gel permeation chromatography, nuclear magnetic resonance spectroscopy, dynamic light scattering, particle size distribution, zeta potential, and critical micelle concentration, provide detailed insights into the copolymers and the emulsions they form. The results demonstrate that the RAFT-polymerized surfactants offer long-lasting stability and effectively disperse both common oil-in-water emulsions and highly viscous and hydrophobic polymer latexes. These surfactants outperform traditional small molecule surfactants by reducing particle size and preventing phase separation, even over extended storage periods. Stable polymer-water interfaces are achieved through HLB control, tailored by monomer composition, and the final product requires no additional purification since polymerization occurs in liquid surfactants. While small molecules contribute to rapid micelle formation, the polymeric components enhance long-term stability through steric repulsion and slower dynamics. This method enables even the emulsification of polymers with submicron particle size, which ordinarily requires emulsion polymerization. Integrating biobased polymeric surfactants with advanced polymer processing techniques opens new possibilities for transforming highly hydrophobic polymers into latexes, facilitating downstream applications. This innovation enhances the environmental sustainability of surfactant production and broadens the potential for polymer emulsification technologies. Additionally, the integrated solution-processing approach demonstrated here can be applied to other emerging polymers, where judiciously selected nonvolatile solvents facilitate the polymerization and play a role in the final application.

Chemical synthesis, structural and magnetic properties of Al-doped neodymium orthoferrite

Crystalline and single phase of Al doped orthoferrite with stoichiometry NdFe1-xAlxO3 was synthesized by a hydrothermal method. The effect of Al doping on the structure features was investigated by powder X-ray diffraction (PXRD) technique. In this sense, Rietveld refinement was applied in refining the PXRD data. Scanning electron microscopy (SEM) was used to characterize the morphology. And from image analyses show a sub-micron particle size distributions for all samples. Using hydrothermal synthesis method, a micro-sized particle distribution is reached. Measurement of magnetic hysteresis loops showed that the highest coercivity (Hc) obtained was 5.2 kOe for the sample with x=2. Compared to previous results using sol-gel synthesis, the hydrothermal method used in this study showed improved magnetization properties.

Soft X-ray spectromicroscopic proof of a reversible oxidation/reduction of microbial biofilm structures using a novel microfluidic in situ electrochemical device

In situ electrochemistry on micron and submicron-sized individual particles and thin layers is a valuable, emerging tool for process understanding and optimization in a variety of scientific and technological fields such as material science, process technology, analytical chemistry, and environmental sciences. Electrochemical characterization and manipulation coupled with soft X-ray spectromicroscopy helps identify, quantify, and optimize processes in complex systems such as those with high heterogeneity in the spatial and/or temporal domain. Here we present a novel platform optimized for in situ electrochemistry with variable liquid electrolyte flow in soft X-ray scanning transmission X-ray microscopes (STXM). With four channels for fluid control and a modular design, it is suited for a wealth of experimental conditions. We demonstrate its capabilities by proving the reversible oxidation and reduction of individual microbial biofilm structures formed by microaerophilic Fe(II)-oxidizing bacteria, also known as twisted stalks. We show spectromicroscopically the heterogeneity of the redox activity on the submicron scale. Examples are also provided of electrochemical modification of liquid electrolyte species (Fe(II) and Fe(III) cyanides), and in situ studies of electrodeposited copper nanoparticles as CO2 reduction electrocatalysts under reaction conditions.

Sol-Gel Derived Alumina Particles for the Reinforcement of Copper Films on Brass Substrates.

The aim of this study is to provide tailored alumina particles suitable for reinforcing the metal matrix film. The sol-gel method was chosen to prepare particles of submicron size and to control crystal structure by calcination. In this study, copper-based metal matrix composite (MMC) films are developed on brass substrates with different electrodeposition times and alumina concentrations. Scanning electron microscopy (FE-SEM) with energy-dispersive spectroscopy (EDS), TEM, and X-ray diffraction (XRD) were used to characterize the reinforcing phase. The MMC Cu-Al2O3 films were synthesized electrochemically using the co-electrodeposition method. Microstructural and topographical analyses of pure (alumina-free) Cu films and the Cu films with incorporated Al2O3 particles were performed using FE-SEM/EDS and AFM, respectively. Hardness and adhesion resistance were investigated using the Vickers microindentation test and evaluated by applying the Chen-Gao (C-G) mathematical model. The sessile drop method was used for measuring contact angles for water. The microhardness and adhesion of the MMC Cu-Al2O3 films are improved when Al2O3 is added. The concentration of alumina particles in the electrolyte correlates with an increase in absolute film hardness in the way that 1.0 wt.% of alumina in electrolytes results in a 9.96% increase compared to the pure copper film, and the improvement is maximal in the film obtained from electrolytes containing 3.0 wt.% alumina giving the film 2.128 GPa, a 134% hardness value of that of the pure copper film. The surface roughness of the MMC film increased from 2.8 to 6.9 times compared to the Cu film without particles. The decrease in the water contact angle of Cu films with incorporated alumina particles relative to the pure Cu films was from 84.94° to 58.78°.

Extended Monte Carlo modeling for submicron particle size measurement under high light extinction conditions.

The light extinction method (LEM) based on Lambert Beer's law (LB) is widely used to characterize particle size distribution (PSD) in multiphase flow. However, as the optical thickness increases with concentration, the phenomenon of multiple scattering is enhanced, potentially leading to reduced accuracy and a limited application range. In this study, an extended Monte Carlo-based light extinction model (EMC) was developed, which was initially employed to calculate and evaluate the impact of multiple scattering. Subsequently, it was used to predict the extinction spectrum that incorporates multiple scattering effects under varying concentrations. To validate the modeling, a compact setup was constructed to perform a series of experiments on polystyrene and silica dioxide (SiO2) suspensions. A differential evolution algorithm was also implemented for the inversion of PSD based on spectral content, with the incorporation of an improved coefficient matrix that considers multiple scattering effects. In comparison to the linear LB model, the EMC exhibits a markedly enhanced capacity in handling higher particle concentrations and improving measurement accuracy. For a 700 nm PS suspension, the particle size inversion error of the EMC can be kept within 4% (93.86% for the LB model) compared with the nominal value, even with an optical thickness of 5.

Carbon primer layer morphological effect on the lithium manganese iron phosphate positive electrode performances for lithium-ion batteries

The application of lithium manganese iron phosphate (LMFP) electrodes is important for enhancing the energy density of phosphate-based positive electrodes. However, their practical implementation is hindered by the deteriorating collector–electrode interface caused by submicron-sized particles with carbon-coated surfaces of LMFP. The morphology of carbon particles on current collector affects the efficiency of the primer layer, despite its role in strengthening the electrical contact between LMFP and the aluminum (Al) current collector. Incorporating carbon nanotube (CNT)-type carbon into the primer layer weakens the electrical connection between the electrode mass and current collector, indicating that CNT-coated Al does not effectively reduce contact resistance. In contrast, the planar shape of graphene-type carbon provides a more effective connection between LMFP and the Al plate, resulting in minimal contact resistance. This improvement in contact resistance enhances cycleability by significantly reducing polarization during cycling, which prevents electrolyte decomposition on the LMFP surface. Given the significant impact of carbon morphology on interfacial contact, it is essential to rationally control the morphology of the carbon primer layer to optimize the properties of the positive electrode.

Material Trends and Clinical Costings in Systematically Identified CDER‐Approved Nanomedicines

AbstractResearch into mechanisms and potential applications of nanomaterials in medicine has expanded steadily in recent decades, with increasing translational focus. Development costs, including for clinical trials, are often cited as factors limiting the translational viability of novel nanomedicines, especially compared to small new molecular entities (NMEs) and therapeutic biologics. Yet, to date, there has been no systematic investigation into the clinical programs or costs of translating and commercializing nanomedicines, nor a comparison to NMEs and therapeutic biologics, to support these claims. Here, nanomedicines approved by the United States Food and Drug Administration's Center for Drug Evaluation and Research (CDER) from 2011 to 2023 are systematically identified and categorized. Nanomedicines were identified as formulations where submicron particle size contributes to product function. Like biologics and NMEs, nanomedicines are most frequently approved for oncological indications. Notably, all anti‐cancer nanomedicines are indicated to treat orphan diseases, which is representative of the potential for nanomedicines to occupy pharmaceutical niches in treating diseases affecting smaller patient cohorts. The median estimated cost of pivotal trials for nanomedicines is 47% that of biologics and NMEs approved in the same timeframe. The findings indicate higher manufacturing costs in nanomedicine development may be mitigated by savings elsewhere, increasing translational viability.

Enhanced strength–ductility synergy of SiC particles reinforced aluminum matrix composite via dual configuration design of reinforcement and matrix

To overcome the strength-ductility conflict in particle reinforced aluminum matrix composites (PRAMCs), a novel dual configuration strategy of microstructure was proposed in this work. The dual configuration including both heterogeneous grain structure and hybrid reinforcements was obtained by powder metallurgy, which was designed as submicron-sized SiC particles (SiCsm)/Al and micron-sized SiC particles (SiCm)/2024Al components. Representative alternating coarse grain (CG) bands containing SiCm and ultra fine grain (UFG) bands with dispersed SiCsm were revealed in microstructural characterizations. Compared to corresponding homogeneous composites with the same fraction particles, the dual configuration composite achieved simultaneous enhancement in strength and ductility and remained a comparable Young’s modulus of 98GPa, which represented 442 MPa in yield strength, 590 MPa in ultimate strength and 8.7 % in fracture elongation. The extra strength provided by hetero-deformation induced (HDI) strengthening is a potential dominant strengthening mechanism. The intrinsic toughening mechanisms primarily contribute to HDI strain hardening and enhanced dislocation accumulation capacity, while the extrinsic toughening mechanisms presumably attribute to more uniform microcrack distribution and blunting effect of CG zones on cracks. Our work provides a feasible route including ball milling and powder assembly to preparate high-modulus aluminum matrix composites for strength-ductility balance design.

Particle Matter determination in Biosimilar Parenteral Product by the Application of Dynamic Light Scattering (DLS) Followed by Statistical Evaluation

Particulate matter in parenteral dosage forms can emerge from numerous causes, external, intrinsic, as well as inherent within the product, with a special emphasis on biopharmaceuticals. Aqueous impurities, pharmaceutical precipitates, dirt, glass, rubber, pollutants from the environment, fibres, and various other insoluble materials are all common sources of particulates. When assessing the possible harm to patients, particulate matter size is a crucial issue to consider. Particles as fine as 2 μm overall diameter were found related with microthrombi development. The DLS (Dynamic Light Scattering) technique has been used to measure and control the subvisible particulate particles in biopharmaceutical parenteral drug products since the technique can measure the submicron particle size in the parenteral formulation. The purpose of using DLS is to measure and control the subvisible particles in a biopharmaceutical formulation. A generic biopharmaceutical product viz. Calcitonin Salmon injection was used for particulate matter analysis by using Dynamic Light Scattering. DLS is a non-invasive method for detecting the size of suspended particles as well as molecules which is used for the control and optimization of processes, and the improvement of product quality and performance by analysing the time-dependence in regard to intensity of the dispersed light (auto correlation) to determine the diffusion speed (Brownian motion) of particles/molecules, and subsequently determine the hydrodynamic size. Keywords: Particulate matter; DLS; Biosimilars; Parenteral dosage forms

Turbostratic carbon nanofibers produced from C2HCl3 over self-dispersing Ni-catalyst doped with W and Mo

In this research, a self-dispersing 92Ni-4Mo-4W catalyst showing high productivity towards the H2-assisted synthesis of turbostratic carbon nanofibers was proposed. The effect of reaction temperature on the efficiency of 92Ni-4Mo-4W alloy in the decomposition of trichloroethylene was studied. It was found that in the temperature range of 580–620 °C, the most rapid destruction of the initial alloy followed by the growth of carbon material is realized. This is confirmed by the minimum induction period (9–11 min) and the maximum carbon yield (95–107 g/gcat). As revealed, the catalytically active particles of submicron size contain uniformly distributed Ni, Mo, and W. It is demonstrated that the decomposition of trichloroethylene over the 92Ni-4Mo-4W catalyst results in the formation of a turbostratic carbon material with a segmented structure, containing a minimum quantity of amorphous carbon and possessing high textural characteristics (specific surface area of 330–410 m2/g; pore volume of 0.48–0.58 cm3/g).

Effects of homogenization temperature on microstructure, mechanical properties and corrosion behavior of binary Zn-Mn alloys extruded at different temperatures

In order to optimize the mechanical properties (MPs) of biodegradable Zn-based alloys, many researches have been conducted. However, the effect of homogenization treatment before the plastic deformation process on the MPs of biodegradable Zn-based alloys has not received sufficient attention, although it has been demonstrated to play an important role in improving the MPs of Al- and Mg-based alloys. In this work, as-cast Zn-0.8 wt% Mn alloys were firstly homogenized at two different temperatures (330 and 390 °C) followed by quenching and then extruded at three different temperatures (170, 230 and 300 °C). This work revealed the effects of homogenization temperature (HT) on microstructure, MPs and corrosion behavior of Zn-0.8 wt% Mn alloys extruded at different temperatures. The results showed that compared to the alloy homogenized at 330 °C (HT330), the alloy homogenized at 390 °C (HT390) has less precipitation of micron-sized MnZn13 particles in the homogenization process. During the subsequent extrusion processes at 170 and 230 °C, more submicron-sized MnZn13 particles are precipitated and finer Zn grains are formed in the HT390 alloys than in the HT330 alloys. Correspondingly, the two extruded HT390 alloys exhibit elongations of up to 133 % and 86 %, respectively, which are much higher than the 71 % and 65 % of the two extruded HT330 alloys. However, when the extruding temperature is elevated to 300 °C, high HT causes decrease in the fraction of both the micron- and submicron-sized MnZn13 particles as well as coarsening of Zn grains, followed by an increase in the strength of the as-extruded alloy. In addition, high HT is conductive to improving the corrosion resistance of the as-extruded alloys regardless of the extrusion temperature.