Particle Surface Research Articles

Impact of particle size and associated minerals on rare earth desorption and incorporation mechanisms in a South American ion-adsorption clay

This research delves into the intricate nexus of particle size, mineralogical composition, surface attributes, elemental mapping, and rare earth element (REE) adsorption mechanisms within an ion-adsorption clay sample from South America. The investigation entails the fractionation of the ion-adsorption clay into three size categories: S1 (< 0.25 mm), S2 (0.25–0.5 mm), and S3 (0.5–2 mm). Each fraction undergoes meticulous characterization to unveil its elemental composition, mineralogical composition, surface area, morphological characteristics, elemental mapping, and the mechanisms governing REE incorporation. The results indicate that S1 has 31% physiosorbed, 8% chemisorbed, and 61% mineralized REEs, while S2 has 40% physiosorbed, 5% chemisorbed, and 55% mineralized REEs, and S3 has 24% physiosorbed, 5% chemisorbed, and 71% mineralized REEs. The physisorbed REEs are attributed to the presence of kaolinite, conducive to mostly physisorption. In terms of grain size and REE content/type relationship, the results show that REE content decreases with increasing grain size; however, there is not a clear trend in terms of REE occurrence modes with grain size. Heavy rare earth elements (HREEs) are discernibly favored in adsorption over light rare earth elements (LREEs). This preference is underpinned by the weathering processes that led to the formation of ion-adsorption clay, which facilitated the transport and accumulation of HREEs. Notably, the ion-adsorption clay encompasses a substantial content of mineralized REEs, necessitating more demanding extraction methodologies, such as acid baking followed by water leaching if complete extraction of all REEs is desired. Among the desorbable REEs, physisorption dominates, encompassing over 80% of the total. Chemisorbed REEs exhibit versatility in association with various minerals, encompassing kaolinite, quartz, and goethite. In essence, this study unveils the intricate interplay between particle dimensions, mineralogical constitution, surface attributes, and REE adsorption modes within this ion-adsorption clay sample. The ion-adsorption clay in this study contains a significant portion of mineralized REEs that cannot be extracted using the mild conditions typically employed for the desorption process. Additionally, the REE concentration in this ion-adsorption clay is notably higher than the average found in clay deposits worldwide, reaching levels comparable to those of regolith deposits in China, which are a major global source of REEs. This remarkable concentration of REEs, along with the unique modes of their occurrence in this deposit, presents a significant interest to the scientific community.

Edoxaban enfolded beta-1,4-poly-d-glucosamine nanoparticles for targeting eponym Stuart–Prower factor for treatment of venous thrombosis

The present research looked for ways to develop shielded nanoparticles (NPs)-drug transporters made of chitosan (CS) to enhance the bioavailability of edoxaban tosylate monohydrate (ETM) for oral administration by examining the correlation among design aspects and data from experiments using response surface methodology (RSM). ETM-loaded CS nanoparticles (ETM-CS-NPs) were developed using the ionic gelation of CS with tripolyphosphate (TPP). Utilising Zeta-sizer and scanning electron microscopy, the ETM-CS-NPs were evaluated for particle size (PS), zeta potential (ZP), surface morphology, polydispersity index (PDI), entrapment efficiency (EE) and drug loading (DL). Drug and polymer interactions in NPs were assessed using Fourier transform infra-red spectroscopy. The response surface approach and Design-Expert software optimised the ETM-CS-NPs. Using RSM, the effects of independent variables such as the amount of CS, the amount of TPP, and the amount of glacial acetic acid on PS, PDI and ZP were analysed. The optimal combination of PS (354.8 nm), PDI (0.509), ZP (43.7 + mV), % EE (70.3 ± 1.3) and % DL (9.1 ± 0.4) has been identified for the optimised ETM-CS-NPs. ETM-CS-NPs’ anticoagulant activity was evaluated using activated partial thromboplastin time (aPTT), prothrombin time (PT) and thrombin time (TT) assays. In conclusion, a practical and consistent method has been established, and its application has been proven in vitro, indicating its utility for future studies of the biological distribution of ETM-CS-NPs in vivo for specific antithrombotic treatments.

Characterization and Comparative Investigation of Hydroxyapatite/Carboxymethyl Cellulose (CaHA/CMC) Matrix for Soft Tissue Augmentation in a Rat Model.

This study endeavors to develop an injectable subdermal implant material tailored for soft tissue repair and enhancement. The material consists of a ceramic phase of calcium hydroxyapatite (CaHA), which is biocompatible, 20-60 μm in size, known for its biocompatibility and minimal likelihood of causing foreign body reactions, antigenicity, and minimal inflammatory response, dispersed in a carrier phase composed of carboxymethyl cellulose (CMC), glycerol, and water for injection. The gel formulation underwent comprehensive characterization via various analytical techniques. X-ray diffraction (XRD) was employed to identify crystalline phases and investigate the structural properties of ceramic particles, while thermogravimetric analysis (TGA) was conducted to evaluate the thermal stability and decomposition behavior of the final formulation. Scanning electron microscopy (SEM) was utilized to examine the surface morphology and particle size distribution, confirming the homogeneous dispersion of spherical CaHA particles within the matrix. SEM analysis revealed particle sizes ranging from approximately 20-60 μm. Elemental analysis confirmed a stoichiometric Ca/P ratio of 1.65 in the hydroxyapatite (HA) structure. Heavy metal content exhibited suitability for surgical implant use without posing toxicity risks. Rheological analysis revealed a storage modulus of 58.6 and 68.9 kPa and a loss modulus of 21.7 and 24.8 kPa at the frequencies of 2 and 5 Hz, respectively. 150 μL of sterilized CaHA/CMC was injected subcutaneously into rats and compared with a similar product, Crystalys, to assess its effects on soft tissues. Skin tissue samples of rats were collected at specific intervals throughout the study (30, 45, 60, 90 and 120 days), and examined histologically. Results demonstrated that CaHA/CMC gel led to a significant increase in dermal thickness, elastic fibers, and collagen density. Based on the findings, the formulated CaHA/CMC gel was found to be biocompatible, biodegradable, nonimmunogenic, nontoxic, safe, and effective, and represents a promising option for soft tissue repair and augmentation.

Synthesis of Mesoporous Tetragonal ZrO2, TiO2 and Solid Solutions and Effect of Colloidal Silica on Porosity.

Metal oxides possessing a large surface area, pore volume and desirable pore size provide more varieties and active industrial potentials. Nevertheless, it is very challenging to produce crystal metal oxides while keeping satisfactory porosity features, especially for ternary compositions. High temperature is usually needed to produce crystal metal oxides, which readily leads to the collapse of the pore structure. Herein, by employing a 'soft' dispersant agent and a hard silica template, ZrO2, TiO2 and Zr-Ti solid solutions having a tetragonal crystal structure are produced and the silica-leached materials are characterized from macroscopic to atomistic scales. The micron-sized particulate powders are composed of nanoscale 'building blocks', with crystallite sizes between ~8 and 21 nm. These polycrystalline ceramic powders exhibit a high specific surface area (up to ~200 m2·g-1) and pore volume (up to 0.5 cm3·g-1), with a pore size range of ~5-20 nm. Importantly, the Zr/Ti-O-Si-OH chemical bonds exist on the particle surface, with about two-thirds of the surface covered by silica. The hydroxyl groups can further post-graft organic ligands or directly associate with species. Synthesized mesoporous metal oxides are highly homogenous and could potentially be used in various applications because of their tetragonal structure and porosity features.

Enabling the Strengthened Structural and Interfacial Stability of High‐Nickel LiNi0.9Co0.05Mn0.05O2 Cathode by a Coating‐Doping‐Microstructure Regulation Three‐In‐One Strategy

AbstractHigh‐nickel layered cathodes exhibit great promise in advancing high‐energy‐density batteries owing to their significant advantages in high energy capacity and low cost, but they suffer severe structural and interfacial deterioration during cycling, resulting in safety risk and reduced cycle life. Herein, drawing inspiration from the low melting point infusion capability of Sb2Se3, a three‐pronged strategy aimed at simultaneously achieving coating on primary and secondary particles surface, Sb doping and elongated and slimed primary particle morphology is proposed and developed to fortify the structural and interfacial stability of high‐nickel LiNi0.9Co0.05Mn0.05O2 (NCM90) cathode. The “melted and infused” Sb2Se3 plays a beneficial role in the defensive effect on primary and secondary particle's surfaces, mitigating the interfacial deterioration. In addition, the enhanced structural stability is achieved by both Sb5+ doping and regulated primary particle morphology, contributing to the alleviated particle breakage and ultimately reinforced cycling stability. Consequently, the Sb2Se3‐NCM90 electrodes significantly improve cycling performance, which maintain higher capacity retentions of 96.6% at 4.3 V after 100 cycles and 80.2% at 1C/5C after 500 cycles. The proposed coating‐doping‐microstructure regulation three‐in‐one strategy for improving the cycling stability of high‐nickel NCM cathodes offers innovative ideas for the design and advancement of high‐energy‐density lithium‐ion batteries.

Effect of Surface Area, Particle Size and Acid Washing on the Quality of Activated Carbon Derived from Lower Rank Coal by KOH Activation

The use of coal-derived activated carbon (AC) for water treatment applications demands more sustainable production methods, with chemical activation emerging as a promising alternative to thermal activation due to its higher AC quality, lower carbon burn-off, and higher yield. The study explored the effect of surface area, particle size and acid washing on the quality of AC derived from three seams of lower-rank Collie coal under the same activation conditions with potassium hydroxide (KOH). The quality of AC was determined by surface area and iodine number. The study demonstrates that Collie coal, suitable for AC production via KOH activation, yielded iodine numbers of 640 and 900 mg/g, with yields of 53 and 57 wt.%. Particle size influenced AC yield, with finer particle sizes yielding AC at 57–59 wt.%, whereas coarser ones yielded around 58–65 wt.%. SEM analysis shows the well-developed porous structure in Collie coal-derived activated carbons, with cleaner particles after acid washing. A positive correlation exists between coal surface area and AC iodine numbers, with higher values in coal samples correlating to increased iodine numbers in resulting AC. The regression model’s predicted values yield a coefficient of determination (R²) of 0.99.

Transient electrophoresis of colloidal particles in a salt-free medium

A general theory is developed for the time dependent transient electrophoretic mobility of spherical colloidal particles in a salt-free liquid medium containing only counterions when a step external electric field is suddenly applied to the colloidal suspension. It is found that as in the case of the steady electrophoretic mobility in a salt-free medium, there is a certain critical value of the particle surface charge separating two cases, that is, the low-surface-charge case and the high-surface-charge case. In the latter case the counterion condensation takes place near the particle surface. For the low-surface charge case, the transient electrophoretic mobility agrees with that of a sphere in an electrolyte solution in the limit of very low electrolyte concentrations. For the high-surface-charge case, however, the transient mobility becomes independent of the particle surface charge because of the counterion condensation effects. A simple expression is derived for the ratio of the transient electrophoretic mobility to the steady electrophoretic mobility, which is found to take the same form irrespective of the magnitude of the particle surface charge. Using this equation, it is now possible to predict how the system will approach its final steady state.

Technical cleanliness of additively manufactured Inconel 718: a comparative study of surface treatment methods

PurposeMetal laser-powder-bed-fusion using laser-beam parts are particularly susceptible to contamination due to particles attached to the surface. This may compromise so-called technical cleanliness (e.g. in NASA RPTSTD-8070, ASTM G93, ISO 14952 or ISO 16232), which is important for many 3D-printed components, such as implants or liquid rocket engines. The purpose of the presented comparative study is to show how cleanliness is improved by design and different surface treatment methods.Design/methodology/approachConvex and concave test parts were designed, built and surface-treated by combinations of media blasting, electroless nickel plating and electrochemical polishing. After cleaning and analysing the technical cleanliness according to ASTM and ISO standards, effects on particle contamination, appearance, mass and dimensional accuracy are presented.FindingsContamination reduction factors are introduced for different particle sizes and surface treatment methods. Surface treatments were more effective for concave design features, however, the initial and resulting absolute particle contamination was higher. Results further indicate that there are trade-offs between cleanliness and other objectives in design. Design guidelines are introduced to solve conflicts in design when requirements for cleanliness exist.Originality/valueThis paper recommends designing parts and corresponding process chains for manufacturing simultaneously. Incorporating post-processing characteristics into the design phase is both feasible and essential. In the experimental study, electroless nickel plating in combination with prior glass bead blasting resulted in the lowest total remaining particle contamination. This process applied for cleanliness is a novelty, as well as a comparison between the different surface treatment methods.

Study on the stability and properties of carbon neutral methanol in blends with diesel fuel

As the simplest liquid fuel, methanol can be sustainably produced from carbon dioxide and renewable energy sources. It is one of the most competitive green fuels. However, there are difficulties in being miscible with conventional fuels when it is used as a blended fuel. In this paper, the furan from biomass is used as the co-solvent of methanol blended fuel, which is expected to address the issue. In this study, not only surface tension, electrical conductivity, and particle size were used to characterize the macroscopic and microscopic structures of carbon neutral methanol blended fuels, and fuel properties including the density, lower calorific value and corrosivity of the mixed fuel have also been discussed. Results indicate that biomass furan reduces the surface tension and keeps the mixed fuel in a microemulsion state for more than 45 days. It increases the fuel density, reduces the unit calorific value cost, and slightly aggravates the corrosion. Carbon neutral methanol fuel, with the help of biomass furan, can be used together with traditional fossil fuels, providing a potential effective path for the efficient and convenient application of new carbon neutral fuels and biomass fuels.

A systematic study of the impact of aromatic/aliphatic amines and protein corona as coatings of iron oxide magnetic nanoparticles on the interaction with DPPC Langmuir monolayers

The nature of chemical groups exposed by nanoparticles determines their interaction with biological systems, especially with cell membranes. Amino groups are one of the most used to guide nanoparticles within cells. Aromatic and aliphatic amines can establish different types of interactions with lipids, and this may condition the nanoparticles' mode of action as well as their fate. This work is focused on investigating how aromatic and aliphatic amines present at the surface of iron oxide magnetic nanoparticles influence their interaction with Langmuir monolayers as models of cell membranes. For this, we synthesized iron oxide magnetic nanoparticles coated with an arylamine (aromatic) and polyethylenimine (aliphatic). Also, the effect of human serum albumin at the particle surface was evaluated to test how protein corona governs the physicochemical properties of the nanoparticles. The interaction of these nanoparticles with monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine was systematically studied employing three different experimental approaches. The results signal a notorious influence on the type of amine in the interactions established with the phosphocholine in the model membrane. Managing this knowledge is of ongoing interest for nanomaterials design and improved bioapplications.

Construction of a novel OS/BiVO4 catalyst for enhancing the photocatalytic degradation performance of sulfonamide

Exploiting of high-value-added environmental materials related to oily sludge (OS) is an important development direction for OS resource utilization. A series of OS/BiVO4 catalysts were synthesized by activation-pyrolysis and hydrothermal methods. Photocatalytic performance was estimated through sulfanilamide (SA) degradation (SA) under visible light irradiation. The OS/BiVO4–20% has the best photodegradation ability for SA. The degradation rate of SA was about 97.8% after six hours of visible light irradiation. The first-order kinetics degradation rate constants of OS/BiVO4–20% for SA is 8.3 times that of pure BiVO4. The radical quenching and ESR experiments reveal that the hole (h+) and hydroxyl radical (·OH) were the primary active species for SA photocatalytic degradation. The presence of OS and H2O2 can significantly improve the charge separation efficiency, and inhibit electron-hole complexes, thereby extending the lifetime of electron carriers and producing many active hydroxyl radicals and holes on the surface of catalyst particles. Due to the introduction of OS, OS/BiVO4 has good texture properties and high oxygen absorption content, which is also conducive to the photodegradation of SA. Fourier-transform infrared (FTIR), in combination with two-dimensional correlation spectroscopy (2D-COS), indicated that the C–N (1351 cm-1), CC (1450 cm-1), SO2–N (1116 or 1182 cm-1), and N–H (1636 cm-1) groups can change in turn during the catalytic degradation process. This work improves the surface properties of BiVO4 semiconductor materials by introducing OS, thereby increasing the photodegradation efficiency of BiVO4 catalysts against antibiotics, which provides valuable insights into the design of next-generation photocatalysts.

High-Resolution Two-Phase Velocimetry Of Aspherical Particles Using Wavelet-Based Optical Flow Velocimetry (WOFV) Benchmarked With Fully Resolved Direct Numerical Simulations

Several techniques exist to measure the carrier and dispersed phases in multi-phase flows. Particle image velocimetry (PIV) analyzes the carrier phase by cross-correlating particle images, but its resolution is limited by the size of the interrogation window, making it difficult to resolve fine-scale turbulent structures. Particle tracking algorithms capture translational motion of dispersed particles well, but struggle with rotational motion, especially for irregular and aspherical particles. Currently, there is no method that universally measures both the carrier phase velocity field and the translational and rotational motions of dispersed particles. This study evaluates wavelet-based optical flow velocimetry (wOFV) for motion estimation in multi-phase flows, focusing on dispersed ellipsoidal particles and their surrounding turbulent carrier flow using synthetic image data. The research proceeds in two phases: first, the rigid motion of ellipses, including translational and rotational components, is analyzed using wOFV-generated dense motion fields. The results highlight the critical role of the regularization weighting parameter λ. Higher λ values improve translational motion estimation, while an optimal λ avoids under-regularization and non-physical structures in rotational motion. wOFV maintains accuracy in combined motion scenarios with optimal λ values. In the second phase, wOFV captures the turbulent carrier flow around an aspherical particle, benchmarked against DNS data and compared to PIV. wOFV outperforms PIV in resolving finer structures near the particle surface and in accurately representing the wake region. Error analyses confirm wOFV’s superior performance, with optimal results within a specific λ range. In conclusion, wOFV is a highly effective tool for the analysis of multi-phase flow dynamics, providing greater resolution and accuracy than PIV, especially in complex scenarios involving aspherical particles.

Lithium-Ion battery silicon Anodes: Surface engineering with novel additives for enhanced ion and electron transport

Silicon (Si) stands as a promising candidate for high-capacity anode materials in the next-generation lithium-ion batteries (LIBs) due to extremely high specific capacity. However, silicon application is hindered by its inherently poor electron and ion conductivities, as well as structural instability during the repeated charging/discharging. To address these challenges, a novel functional surface modification agent, diethylenetriaminepenta(methylenephosphonic) acid (DTPMP), was decorated on the surface of silicon particles for the first time. The experimental results demonstrate that the DTPMP effectively enhances the cohesion between nano Si particles. This study combines experimental observations with theoretical calculations to analyze the nucleophilic and electrophilic sites of DTPMP and carboxymethyl cellulose (CMC), elucidating the existence state of DTPMP on the nano Si surface. Furthermore, by examining the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), along with the electrostatic potential (ESP) of DTPMP and solvent molecules in conjunction with Li+, the impact of the phosphate group on the diffusion of Li+ and electrons at the nano Si surface was studied. The electron density difference (EDD) maps for DTPMP and CMC reveal that DTPMP exhibits a more pronounced response in the presence of an electric field, suggesting its enhanced role in facilitating Li+ diffusion. This research offers a novel perspective on enhancing the electrochemical performance of nano Si surfaces, paving the way for the development of advanced LIBs with improved energy storage capabilities.

Formulation of nanoemulsion parijoto fruit extract (Medinilla Speciosa) with variation of tweens stabilizers.

Nanotechnology has substantial potential for development due to its ability to modify surface characteristics and particle size, facilitating enhanced absorption of functional food compounds and controlled release of active substances to mitigate adverse effects. Nanoemulsion, a stable colloidal system formed by blending oil, emulsifier, and water, was identified as nanotechnology with promising applications. However, investigations into the impact of surfactants on characteristic nanoemulsions need to be more varied. This research gap necessitated further exploration in the advancement of nanotechnology-based foods. The parijoto fruit (Medinilla speciosa), an indigenous plant species in Indonesia, has yet to undergo extensive scrutiny for its potential use as a functional and nutraceutical food. Anthocyanins, a principal compound in the parijoto fruit, had exhibited efficacy in reducing the risk of cardiovascular disease diabetes, demonstrating anti-inflammatory and antioxidant properties. This study aimed to investigate the characteristics of nanoemulsion formulations derived from parijoto fruit extract and to evaluate an optimum condition with various tween surfactants. The findings from this investigation could furnish valuable insights for the further advancement of anthocyanin nanoemulsions from parijoto fruit extract. The results comprised the characterization of nanoemulsion particle size, polydispersity index, ζ-potential, conductivity, pH, and viscosity. Through mathematical modeling and statistical methods, RSM optimizes nanoemulsion by examining the relationships and interactions between independent and response variables. Furthermore, the characterization of nanoemulsion encompassed ζ-potential, polydispersity, particle size, conductivity, pH, and viscosity. Elevated surfactant concentrations resulted in diminished particle sizes and more uniform size distribution, albeit reaching a plateau where surfactant aggregation and micelle formation ensued. Increased concentrations of surfactant type, concentration, and parijoto extract impacted the physical characteristics of nanoparticle size and polydispersity. The optimal process conditions for nanoemulsion consisting of the type of Tween used are Tween 80, Tween concentration of 12%, and parijoto fruit extract concentration of 7.5%, yielding a desirability value of 0.74, categorizing it as moderate.

Electrophoresis Characterization of Nanoplastic Particle Surface Charge in Dilute Aqueous Electrolytes

Electrophoresis Characterization of Nanoplastic Particle Surface Charge in Dilute Aqueous Electrolytes

Effect of pre-hydrated CAC suspensions on the hydration behavior of CAC pastes

The relatively low hydration rate of calcium aluminate cement (CAC) at 15–35 °C leads to retarded setting time and reduced production efficiency of CAC-bonded castables. To accelerate the hydration rate of CAC within this temperature range, the present work proposes the fabrication of nano-hydrates acting as seeds by pre-hydration of CAC in suspensions. CAC powders are dispersed in water with water-to-solid ratio of 4.5 and stirred for varying durations at 25 °C to achieve different pre-hydration degrees. Then the pre-hydrated CAC suspensions replace a small part of cement in the pastes. The influence of the CAC suspensions addition on the hydration heat release and strength development of fresh CAC pastes at 25 °C is investigated. The results indicate that nano-scale hydrates C2AH8 and AH3 form on the surface of pre-hydrated CAC particles in the suspensions and grow rapidly with the extension of stirring duration. The presence of nano-scale hydrates in the pre-hydrated CAC suspensions is found to shorten the induction period of CAC hydration and thus be beneficial to the accelerated hardening of CAC pastes. The pre-hydrated CAC suspension stirred for 3.5 h has the most significant effect on enhancing early strength of the CAC pastes. At this stage, the pre-hydrated CAC within the suspension is in the accelerated period, and has just begun to precipitate large amounts of nano-scale C2AH8 and AH3 acting as seeds to catalyze the hydration and refine the pore structure of CAC pastes.

The impact of nanoparticle surface topography on the interfacial mechanical behavior and microstructure of polyvinyl alcohol composites

The interfacial mechanical strength between nanoparticle and matrix is one of the key factors affecting the mechanical properties of nanoparticulate-polymer composites. Based on the structural composition of a nanoscale iron particle/polyvinyl alcohol composite, this study employed molecular dynamics simulations to investigate the stress-response behavior and microstructural evolution of Fe/PVA/Fe interface models with different surface morphologies under both tensile and shear deformations. The results indicate that when the particle surfaces exhibit different rough structures, the interfacial tensile strength significantly increases with the absolute value of the interfacial binding energy. The order of tensile strength is Type-cube > Type-pyramid > Type-plane. Furthermore, during the shearing process, the protruding structures on the particle surfaces significantly hinder the deformation and unfolding of the matrix molecular chains. As the volume of the protruding structures increases, the interfacial shear strength decreases markedly. The research findings illuminate the mechanisms by which nanoparticle surface morphology at the microscopic molecular scale influences the mechanical properties of nanoparticle-polymer composite materials. These discoveries aid in selecting nanoparticle fillers that enhance the mechanical performance of polymer nanocomposites to a measurable extent.

Solid-state polymer-particle hybrid electrolytes: Structure and electrochemical properties.

Solid-state electrolytes (SSEs) are challenged by complex interfacial chemistry and poor ion transport through the interfaces they form with battery electrodes. Here, we investigate a class of SSE composed of micrometer-sized lithium oxide (Li2O) particles dispersed in a polymerizable 1,3-dioxolane (DOL) liquid. Ring-opening polymerization (ROP) of the DOL by Lewis acid salts inside a battery cell produces polymer-inorganic hybrid electrolytes with gradient properties on both the particle and battery cell length scales. These electrolytes sustain stable charge-discharge behavior in Li||NCM811 and anode-free Cu||NCM811 electrochemical cells. On the particle length scale, Li2O retards ROP, facilitating efficient ion transport in a fluid-like region near the particle surface. On battery cell length scales, gravity-assisted settling creates physical and electrochemical gradients in the hybrid electrolytes. By means of electrochemical and spectroscopic analyses, we find that Li2O particles participate in a reversible redox reaction that increases the effective CE in anode-free cells to values approaching 100%, enhancing battery cycle life.

Catalytic performance of hexagonal boron Nitride@ APTS-SO3H as heterogeneous nanocatalyst for biodiesel production

In this study, the synthesis of a new stable hexagonal boron nitride (h-BN) is reported via the combustion of boric acid and urea using a pyrolysis method. The surface of hBN particles was modified and the physical/chemical properties of h-BN-APTS-SO3H were examined by different characterization, confirming the modification of h-BN. The effects of methanol/acid molar ratio, temperature, and amount of catalyst were investigated. The results showed that the optimal conditions for the esterification of palmitic acid were as follows: methanol to a palmitic acid molar ratio of 30:1, a temperature of 50 °C, a catalyst of 300 mg for 5 h, and a maximum yield of biodiesel of 90 % was achieved. Furthermore, the quality parameters of the biodiesel were made according to ASTM methods [ASTM D445: Kinematic viscosity, ASTM D445: Flash-point, ASTM D92: Ash content, ASTM D6751: Density]. Tests indicate that the quality parameters of the prepared biodiesel were within ASTM standards. Significantly, the h-BN@APTS-SO3H(1) catalyst showed excellent stability on repeated reuse and can be recycled several times without much activity loss.

Irinotecan-loaded magnetite-silica core-shell systems for colorectal cancer treatment

Colorectal cancer represents a worldwide spread type of cancer and it is regarded as one of the leading death causes, along with lung, breast, and prostate cancers. Since conventional surgical resection and chemotherapy proved limited efficiency, the use of alternative drug delivery systems that ensure the controlled release of cytostatic agents possess immense potential for treatment. In this regard, the present study aimed to develop and evaluate the efficiency of a series of irinotecan-loaded magnetite-silica core–shell systems. The magnetite particles were obtained through a solvothermal treatment, while the silica shell was obtained through the Stöber method directly onto the surface of magnetite particles. Subsequently, the core–shell systems were physico-chemically and morpho-structurally evaluated trough X-ray diffraction (XRD) and (high-resolution) transmission electron microscopy ((HR-)TEM) equipped with a High Annular Angular Dark Field Detector (HAADF) for elemental mapping. After the irinotecan loading, the drug delivery systems were evaluated through Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry and differential scanning calorimetry (TG-DSC), and UV–Vis spectrophotometry. Additionally, the Brunauer–Emmett-Teller (BET) method was employed for determining the surface area and pore volume of the systems. The biological functionality of the core-shells was investigated through the MTT assay performed on both normal and cancer cells. The results of the study confirmed the formation of highly crystalline magnetite particles comprising the core and mesoporous silica layers of sizes varying between 2 and 7 nm as the shell. Additionally, the drug loading and release was dependent on the type of the silica synthesis procedure, since the lack of hexadecyltrimethylammonium bromide (CTAB) resulted in higher drug loading but lower cumulative release. Moreover, the nanostructured systems demonstrated a targeted efficiency towards HT-29 colorectal adenocarcinoma cells, as in the case of normal L929 fibroblast cells, the cell viability was higher than for the pristine drug. In this manner, this study provides the means and procedures for developing drug delivery systems with applicability in the treatment of cancer.