Aggregation Of Particles Research Articles

Immunolocalization and Ultrastructure Show Ingestion of Cry Protein Expressed in Glycine max by Heterodera glycines and Its Mode of Action.

Great interest exists in developing a transgenic trait that controls the economically important soybean (Glycine max) pest, soybean cyst nematode (SCN, Heterodera glycines), due to its adaptation to native resistance. Soybean plants expressing the Bacillus thuringiensis delta-endotoxin, Cry14Ab, were recently demonstrated to control SCN in both growth chamber and field testing. In that communication, ingestion of the Cry14Ab toxin by SCN second stage juveniles (J2s) was demonstrated using fluorescently labeled Cry14Ab in an in vitro assay. Here, we show that consistent with expectations for a Cry toxin, Cry14Ab has a mode of action unique from the native resistance sources Peking and PI 88788. Further, we demonstrate in planta the ingestion and localization of the Cry14Ab toxin in the midgut of nematodes feeding on roots expressing Cry14Ab using immunogold labeling and transmission electron microscopy. We observed immunolocalization of the toxin and resulting intestinal damage primarily in the microvillus-like structure (MvL)-containing region of the midgut intestine but not in nematodes feeding on roots lacking toxin. This demonstrated that Cry14Ab was taken up by the J2 SCN, presumably through the feeding tube within the plant root cell that serves as its feeding site. This suggests that relatively large proteins can be taken up through the feeding tube. Electron microscopy showed that Cry14Ab caused lysis of the midgut MvL membrane and eventual degradation of the MvL and the lysate, forming particulate aggregates. The accumulated electron-dense aggregate in the posterior midgut intestine was not observed in SCN in nonCry14Ab-expressing plants. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Novel Fimasartan Fluidized Solid Dispersion and Its Tablet: Preparation, Crystallinity, Solubility, Dissolution, and Pharmacokinetics in Beagle Dogs.

Fimasartan, an angiotensin II receptor antagonist, exhibits low bioavailability due to its poor solubility; consequently, using solubilization technologies is essential to improve its bioavailability. In this study, novel fimasartan fluidized solid dispersion (FFSD) was developed using a fluid bed granulator to enhance the drug solubility andoral bioavailability. An appropriate FFSD was prepared in 50% ethanol using a fluid bed granulator, and its drug dissolution, morphology, and crystallinity were evaluated in comparison to the powdered drug. Moreover, the dissolution in various pH conditions and pharmacokinetics of the FFSD tablet in beagle dogs were investigated compared to the commercial fimasartan tablet. Among the hydrophilic polymers tested, hydroxypropyl methylcellulose (HPMC)showed the highest solubility. The FFSD, composed of fimasartan, HPMC, and microcrystalline cellulose at the weight ratio of 20:10:25, gave a granular aggregation of several particles with a smooth surface. The drug in this FFSD existed as an amorphous state, leading to a greatly increased drug dissolution. The FFSD tablet was prepared by compressing a mixture of FFSD, mannitol, croscarmellose sodium, and magnesium stearate at the weight ratio of 55:40:5:1. The FFSD tablet gave significantly higher drug dissolution, plasma concentrations, maximum plasma concentration (Cmax) andarea under the whole blood concentration-time curve (AUC) values than did the commercial fimasartan tablet. In the beagle dogs, the FFSD tablet (140.39±27.40ng·h/ml) had about a 1.7-fold higher AUC than the commercial fimasartan tablet (80.58±22.18 ng·h/ml), indicating an enhancement in thebioavailability. This novel FFSD tablet could be a potential oral pharmaceutical product with the improved oral bioavailability of fimasartan.

Preparation, physicochemical characterization, ex vivo, and in vivo evaluations of asiatic acid-loaded solid lipid nanoparticles formulated with natural waxes for nose-to-brain delivery

Asiatic acid (AA) has neuroprotective potential for prevention and treatment of Alzheimer's disease. Natural waxes with various ratios of Tween 80 and Span 80 or soybean lecithin were formulated to obtain AA-loaded solid lipid nanoparticles (AA-SLN) to improve direct nose to brain transport. Optimal AA-SLN had particle size below 200 nm with uniform size distribution and zeta potential of nearly -30 mV indicating a low risk of particle aggregation. Formulation with rice bran wax, Tween 80, and soybean lecithin (AA-RwS100) showed the highest entrapment efficiency and yield of >98 % while in vitro AA release of AA-SLN was linearly up to 48 h For ex vivo permeation, confocal laser scanning microscopy (CLSM) and histopathological studies on porcine olfactory mucosa (OM) and respiratory mucosa (RM), AA-SLN showed significantly higher permeation across OM than RM (p < 0.05) up to 6 h and AA-RwS100 also showed the highest amount of drug permeated as confirmed by CLSM results. Although AA-SLN showed non-significantly lower permeation than AA solution (AA-SOL) (p > 0.05), no epithelial and mucosal structure damages were observed in OM treated with AA-RwS100 and RM treated with all AA-SLNs indicating safety for nasal administration while AA-SOL showed significant damage to both OM and RM. In addition, in vivo brain distribution study by fluorescence imaging using Rhodamine (R6g) showed higher brain distribution after intranasal administration of R6g-loaded solid lipid nanoparticles (R6g-SLN) than R6g solution (R6g-SOL) and intravenous administration of R6g-SLN, and R6g-RwS100 also showed the highest brain accumulation at 8 h post administration.

Nonuniversal Dynamics of Hyperbranched Metallo-Supramolecular Polymer Networks by the Spontaneous Formation of Nanoparticles.

Various transient and permanent bonds are commonly combined in increasingly complex hierarchical structures to achieve biomimetic functions, along with high mechanical properties. However, there is a traditional trade-off between mechanical strength and biological functions like self-healing. To fill this gap, we develop a metallo-supramolecular polymer hydrogel based on the hyperbranched poly(ethylene imine) (PEI) backbone and phenanthroline ligands, which have unexpectedly high plateau modulus at low concentrations. Rheological measurements demonstrate nonuniversal metal-ion-specific dynamics, with significantly larger plateau moduli, longer relaxation times, and stronger temperature dependencies, compared to equivalent networks based on model-type telechelic precursors, which cannot be explained by the theory of linear viscoelasticity. TEM images reveal the in situ mineralization of metal ions, which nucleate by the ligand complexation and grow thanks to the spontaneous reducing effect of the PEI backbone. Evidently, the complex lifetime works against Ostwald ripening, resulting in the formation of thermodynamically stable smaller particles. This trend is followed by time-dependent network buildup measurements and is confirmed by a kinetic model for particle formation and aggregation. The spontaneous formation of particles with complex lifetime-dependent sizes can explain the nonuniversal dynamics through the interaction of polymer segments and particles at the nanoscale. This work describes how the polymer backbone can affect the strength and stability of supramolecular bonds, promising for combining high mechanical properties and self-healing comparable to natural tissues.

Nanoporous Submicron Gold Particles Enable Nanoparticle-Based Localization Optoacoustic Tomography (nanoLOT).

Localization optoacoustic tomography (LOT) has recently emerged as a transformative super-resolution technique breaking through the acoustic diffraction limit in deep-tissue optoacoustic (OA) imaging via individual localization and tracking of particles in the bloodstream. However, strong light absorption in red blood cells has previously restricted per-particle OA detection to relatively large microparticles, ≈5µm in diameter. Herein, it is demonstrated that submicron-sized porous gold nanoparticles, ≈600nm in diameter, can be individually detected for noninvasive super-resolution imaging with LOT. Ultra-high-speed bright-field microscopy revealed that these nanoparticles generate microscopic plasmonic vapor bubbles, significantly enhancing opto-acoustic energy conversion through a nano-to-micro size transformation. Comprehensive in vitro and in vivo tests further demonstrated the biocompatibility and biosafety of the particles. By reducing the detectable particle size by an order of magnitude, nanoLOT enables microangiographic imaging with a significantly reduced risk of embolisms from particle aggregation and opens new avenues to visualize how nanoparticles reach vascular and potentially extravascular targets. The performance of nanoLOT for non-invasive imaging of microvascular networks in the murine brain anticipates new insights into neurovascular coupling mechanisms and longitudinal microcirculatory changes associated with neurodegenerative diseases.

Boosting cesium retention efficiency with polyoxometalate-ionic liquid composites: Insights into {WO6} octahedral affinity

Commonly used polyoxometalate (POM) adsorbents exhibit high cesium (Cs) adsorption capacity. However, its impotent ability to sequester adsorbates poses a risk of Cs migration in radioactive waste decontamination and disposal. By leveraging the cesium affinity of POMs and the regulatory properties of ionic liquids (ILs), POM-IL composites hold promise for mitigating the risk of cesium migration through efficient adsorption and retention. Herein, we designed two POM-ILs composed of the phosphotungstate anion (PW) and tetrabutylammonium cation (TBA), i.e., the {WO6}-saturated TBA-PW12 and mono-lacunary TBA-PW11, for the capture and retention of aqueous Cs. The composites were then characterized, and the performance and mechanism of Cs uptake were investigated. TBA-PW12 exhibited ∼300 nm aggregate of particles around 20–60 nm. TBA-PW12 retained the Keggin structural features of PW12O403−, which was proven essential for the binding of Cs+. With a retention efficiency of 97.3% in an NH4Cl eluent and a maximum adsorption capacity of 400.9 mg/g at 338 K, TBA-PW12 exhibited superior Cs capture and retention compared to the POM-IL derived from common Cs adsorbent phosphomolybdate. The Cs adsorption onto TBA-PWs achieved equilibrium within 180 min. Cs uptake by TBA-PWs was monolayer chemisorption of Cs+ accompanied by H+ release, and the removal efficiencies stabilized around initial pH 5–10. Due to intense affinity between {WO6} and Cs+, TBA-PW12 efficiently sequestered Cs + through {WO6} octahedra so that the {WO6}-saturated TBA-PW12 presented better Cs uptake performance than the mono-lacunary TBA-PW11. The IL anion [N(C4H9)4]+ provided a composite-water biphasic interface for aqueous Cs adsorption, while retaining the ability of POM cation PW12O403− to form a stable structure with Cs via its affinity to {WO6} octahedra. These findings support the design of POM-IL composites as efficient adsorbents for capturing and retaining Cs, aiding in the decontamination and safe disposal of radioactive waste, thereby minimizing the risk of nuclide leakage into the environment.

Chemical interference between graphene oxide and polycarboxylate superplasticizer, and the resulting impact on the concrete strength, workability, and microstructure

Graphene oxide (GO) nanoreinforcement is shown to significantly improve the strength and durability of concrete at the expense of mix workability. While polycarboxylate superplasticizers (PCSP) addition has improved GO-cement/mortar strength and workability in existing literature, this article examines if this improvement is translated to concrete with lower cement and water contents. PCSP and GO showed colloidal instability and particulate aggregation through surface charge measurements, presumably caused by divalent Ca 2 + ion interbridging between the GO and PCSP. This chemical interference results in a 26% reduction in 28-day compressive strength and a 20% decrease in the workability of PCSP-treated GO-concrete. Microstructural examination reveals significantly larger pores in PCSP+GO cement than in GO-cement or PCSP-only cement due to the chemical interference induced by PCSP-GO interactions in cement and concrete. Hence, PCSP and GO interactions must be further researched for practical use in concrete structures.

Facile Preparation of Raspberry-Like SiO2@Polyurea Microspheres with Tunable Wettability and Their Application for Oil-Water Separation.

Raspberry-like microspheres have been widely used as superhydrophobic materials, photonic crystals, drug carriers, etc. Nevertheless, their preparation methods, usually consisting of multiple steps, are generally time- and energy-consuming. Herein raspberry-like SiO2@polyurea microspheres (SiO2@PUM) are readily prepared via a one-step precipitation polymerization of isophorone diisocyanate in a H2O/acetone mixture with the presence of SiO2 particles. The sphere size, surface roughness, and SiO2 content of SiO2@PUM are easily adjustable by varying the experimental conditions. TEM and SEM observations reveal that the final SiO2@PUM exhibits a core-shell structure, with polyurea (PU) in the core and SiO2 particles as the shell. In the process, the SiO2 particles were initially located on the PUM surface as a monolayer. With the reaction proceeding, the monolayer of SiO2 particles became thicker, forming a thicker layer of SiO2 particles on PUM due to the accumulation of SiO2 particles, leading to a multilayer structure of SiO2 particles on the shell of SiO2@PUM. The formation mechanism of the raspberry-like SiO2@PUM was thoroughly discussed and ascribed to electrostatic attraction between the positively charged PU and negatively charged SiO2 particles. Once dried, SiO2@PUM was superhydrophobic and turned hydrophilic if water-wetted. Using a layer of SiO2@PUM, effective separation with good reusability for a variety of oil-water mixtures was achieved regardless of the oil density and types of oil-water emulsions. This work presents a novel protocol for the preparation of raspberry-like microspheres with tunable wettability via a rapid and green process, and the resulting microspheres are highly effective for the separation of diverse types of oil-water mixtures.

Aggregate migration and self-organisation properties of asphalt mixtures during compaction process

The objective of this investigation is to analyze the migration behaviours and self-organisation properties of aggregate-asphalt particle system. The three-dimensional discrete element dynamic compaction model was established, and the accuracy and reliability were validated by self-developed particle migration tracking test. The evaluation indices of aggregate particles was measured to investigate the migration behaviours of aggregates and its evolution law. The self-organisation behaviours of aggregate-asphalt particle system were explored combined with the contact behaviours. The results indicate that the migration process of aggregate particles can be delimited into three stages of compaction degree lower than 50%, from 50% to 70%, and above 70%. The larger the aggregate size, the more significant the rotation migration. Under the combined effect of migration and contact, the coarse aggregates migrate to find stable contact points to self-organize the skeleton structure. Asphalt mortar fills the voids eliminated to self-organize the dense structure.

New Insights into the Mechanisms of Toxicity of Aging Microplastics.

Nowadays, synthetic polymer (plastic) particles are ubiquitous in the environment. It is known that for several decades microplastics (MPs) have been accumulating in the World Ocean, becoming available to a large variety of marine organisms. Particularly alarming is the accumulation of aging plastic particles, as the degradation processes of such particles increase their toxicity. The diverse display of negative properties of aging MPs and its effect on biota are still poorly understood. In this study, in vitro experiments modeling the interaction of pristine and UV-irradiated aging polypropylene (PP) fragments with hemocytes and mitochondria of bivalve mollusks Mytilus sp. were performed. The appearance of free radicals in the environment was recorded by spectral characteristics of indicator dyes-methylene blue (MB) and nitroblue tetrazolium (NBT). It was found that due to photooxidation, aging PP fragments sorbed more than threefold MB on their modified surface compared to pristine samples of this polymer. Using NBT, the formation of reactive oxygen species in seawater in the presence of pristine and photoactivated PP was recorded. It was also found that photodegraded PP fragments largely stimulated the development of lipid peroxidation processes in mitochondrial membranes and reduced the stability of hemocyte lysosome membranes compared to pristine PP fragments. In general, the results obtained concretize and supplement with experimental data the previously stated hypothesis of toxicity of aging MPs.

The Effect of Sodium Hexametaphosphate on the Dispersion and Polishing Performance of Lanthanum-Cerium-Based Slurry.

A lanthanum-cerium-based abrasive composed of CeO2, LaOF, and LaF3 was commercially obtained. The effect of sodium hexametaphosphate (SHMP) on powder dispersion behavior was systematically investigated using the combined techniques of liquid contact angle, turbidity, zeta potential (ZP), scanning electron microscopy (SEM), powder X-ray diffraction (XRD) combined with Rietveld refinements, X-ray photoelectron spectroscopy (XPS), and polishing tests. The results indicated that the addition of 0.5 wt.% SHMP dispersant to the 5 wt.% lanthanum-cerium-based slurry produced the most stable suspension with a high turbidity of 2715 NTU and a low wetting angle of 45°. The as-obtained slurry displayed good surface polishing quality for K9 glass, with low surface roughness (Ra) of 0.642 and 0.515 nm (in the range of 979 × 979 μm2) at pH = 6 and 11, respectively, which corresponds to the fact that it has local maximum absolute values of ZP at these two pH values. SEM images demonstrated that after appropriate grafting of SHMP, the particle aggregation was reduced and the slurry's dispersion stability was improved. In addition, the dispersion mechanism was explained based on the principle of complexation reaction, which reveals that the dispersant SHMP can increase the interparticle steric hindrance and electrostatic repulsions. In an acidic environment, steric hindrance dominates, while electrostatic repulsion prevails under alkaline conditions. As expected, this polishing slurry may find potential applications in manufacturing optical devices and integrated circuits.

Investigation of the aggregation behavior of rubber asphalt components induced by short-term Aging: A perspective from molecular dynamic simulations and microscopic tests

The distribution characteristics of different rubber asphalt components remain a subject of debate, particularly under the influence of asphalt short-term aging. This paper leverages the visualization advantages of molecular dynamics (MD) simulation and integrates them with microscopic testing methods to observe morphological variations and property changes in the aggregation of different components induced by short-term aging. Short-term aging of rubber asphalt is simulated using a thin-film oven test (TFOT). By conducting Fluorescence microscope (FM) and scanning electron microscope (SEM) tests, the aggregation behavior of components under changes in fluorescence phase and microstructure before and after short-term aging is revealed. MD simulation is employed to analyze the degree of aggregation between different components before and after short-term aging. SEM test results indicate that the structure becomes looser and forms distinct pits as the rubber asphalt ages. FM test results reveal that the particle size of rubber powder particles in aged rubber asphalt decreases and aggregates gradually. Concurrently, the asphalt phase in rubber asphalt becomes more uniform after aging. MD simulation results demonstrate significant aggregation between asphaltene-asphaltene molecules and asphaltene-rubber powder molecules in aged rubber asphalt. A higher degree of asphaltene aggregation leads to reduce asphalt penetration and increase softening point and viscosity. Furthermore, rubber powder molecular chains can inhibit “π-π stacking,” and “offset π-π stacking” of the asphaltene molecules. Therefore, the accumulation effect in aged rubber asphalt is mitigated compared with aged base asphalt. The research outcomes provided a foundation for further studies on the aging and rejuvenation of rubber asphalt.

Microwave-assisted catalytic dry reforming of methane with CO2 over nitrogen-doped catalysts derived from metal-organic frameworks

Dry reforming of methane (DRM) can convert CO2 into syngas for the production of fuels and chemicals, offering both environmental and energetic benefits. However, its large-scale industrial applications face challenges such as harsh reaction conditions and catalyst deactivation. In this study, metal–organic frameworks (MOFs) derived N-doped Ni-based bifunctional nanomaterials (Ni-Co/NC) were meticulously synthesized to function as microwave absorbers and catalysts. Efficient syngas production was achieved through the microwave-enhanced DRM process over Ni-Co/NC. The results showed that the Ni-Co/NC catalyst significantly increased the conversion of CH4 (∼93.2 %) and CO2 (∼94.8 %). By comparing the changes in the surface properties of the catalysts before and after N-doping, it was found that N-doping enhanced the interaction between the carrier and metal particles, improved the specific surface area and surface basicity, and inhibited the aggregation of metal particles, thereby enhancing catalytic activity. The reaction mechanism was investigated using in-situ infrared spectroscopy, revealing that the formation of intermediates such as carbonates, formates, O-H groups was crucial to improving catalytic activity and stability. Compared to conventional catalytic processes, the catalysts prepared in this study demonstrated stronger catalytic activity and stability in the microwave catalytic process.

Solar evaporation of liquid marbles with composite nanowire arrays

Solar interfacial evaporation is a sustainable technology to produce fresh water. The synergistic realization of broadband light absorption and good thermal insulation is crucial to improving the thermal efficiency. Here, we propose a new structure over the surface of liquid marbles, which via nanowire arrays assembled with composite nanomaterials (Fe3O4/CNT nanoparticles) to enhance the evaporation efficiency. The composite materials can effectively absorb light across the entire solar spectrum. Multiple reflections of light over nanowire array further improve light absorption. The narrow spaces and local particle aggregation of the nanowire array enhance thermal insulation to improve the evaporation efficiency. A series of experiments were conducted to verify the concept. The results showed that liquid marbles with upward Fe3O4/CNT nanowire arrays (Fe3O4/CNT-ULM) enhance the light harvesting ability and thermal insulation. Fe3O4/CNT-ULM at a volume ratio 1:2 provides the highest evaporation rate of 12.25 μg/s, which is about 1.16 and 1.53 times higher than that of Fe3O4 and CNT, respectively. Numerical analysis further illustrates that the combination of composite materials and nanowire arrays enhances concentration of electromagnetic field and heat at the air/water interfaces. This promotes rapid evaporation at the thermal boundary region, which has important implications for the structure design of solar interfacial evaporator.

Turning waste concrete powder into high calcium alkali-activated cementitious materials and artificial aggregates

In order to handle the environmental pollution caused by waste concrete powder, recycled concrete powder (RCP) is utilized to prepare high calcium alkali-activated cementitious materials and artificial aggregates. This study first investigates the high calcium alkali-activated cementitious materials, exploring the effects of different mineral admixtures, liquid-to-solid ratios (L/S), RCP/slag, Na2SiO3 modulus, and Na2O content. The results illustrate that slag powder is the best mineral admixture and the most critical factor affecting cementitious materials. Increasing the slag dosage enhances the generation of C-(A)-S-H, improves the microstructure, and increases compressive strength, with a maximum compressive strength reaching 68.42 MPa. According to these test results, the impact of various factors on RCP aggregates is further explored. The results illustrate that the L/S and slag content are primary factors influencing particle size distribution and strength. Increasing these factors leads to larger aggregate particle sizes and higher strength. The compressive strength of the aggregates at 7d reaches 93.24–-99.5 % of that at 28d, with a maximum strength of 8.2 MPa. Additionally, slag content (10–30 %) and Na2O content significantly impact the physical properties of aggregates, improving apparent density and bulk density while reducing water absorption. To verify the applicability of RCP aggregates, they were used in concrete, and the effects of aggregate strength and replacement rate on concrete performance were explored. The results display that as aggregate strength rises, the mechanical properties of the concrete improve. When RCP aggregates are incorporated, the mechanical properties of the natural concrete decline only slightly (<16.70 %). The probability of aggregate damage increases with decreased RCP aggregate strength or increased RCP aggregate content under pressure. RCP aggregate concrete exhibits better shrinkage resistance compared to natural concrete. The process of utilizing RCP is low-energy, non-polluting, and results in high-performance products, making the large-scale effective utilization of RCP feasible.

Stearic Acid as Polymerization Medium, Dopant and Hydrophobizer: Chemical Oxidative Polymerization of Pyrrole.

In recent years, fatty acids have garnered significant attention as a natural phase-change material and a hydrophobizer due to their biocompatibility and biodegradability. In this study, the utilization of fatty acid is proposed as a polymerization medium for the first time. As a specific reaction, chemical oxidative polymerizations of pyrrole is conducted using ferric chloride as an oxidant in a stearic acid medium. The polymerizations resulted in the production of micrometer-sized polypyrrole (PPy) grains, which are aggregates of atypical primary particles with submicrometer size. The PPy grains are doped with stearic acid, suggesting that the stearic acid functioned as a dopant and a hydrophobizing agent as well as a polymerization medium. The dried PPy grains can adsorb at the air-water interface and function as a liquid marble stabilizer with light-to-heat photothermal properties. The liquid marble can move on a planar air-water interface by Marangoni flow induced by NIR laser light irradiation.

The Application of Nano Zero-Valent Iron in Synergy with White Rot Fungi in Environmental Pollution Control.

Developing efficient and sustainable pollution control technologies has become a research priority in the context of escalating global environmental pollution. Nano zero-valent iron (nZVI), with its high specific surface area and strong reducing power, demonstrates remarkable performance in pollutant removal. Still, its application is limited by issues such as oxidation, passivation, and particle aggregation. White rot fungi (WRF) possess a unique enzyme system that enables them to degrade a wide range of pollutants effectively, yet they face challenges such as long degradation cycles and low degradation efficiency. Despite the significant role of nZVI in pollutant remediation, most contaminated sites still rely on microbial remediation as a concurrent or ultimate treatment method to achieve remediation goals. The synergistic combination of nZVI and WRF can leverage their respective advantages, thereby enhancing pollution control efficiency. This paper reviews the mechanisms, advantages, and disadvantages of nZVI and WRF in pollution control, lists application examples, and discusses their synergistic application in pollution control, highlighting their potential in pollutant remediation and providing new insights for combined pollutant treatment. However, research on the combined use of nZVI and WRF for pollutant remediation is still relatively scarce, necessitating a deeper understanding of their synergistic potential and further exploration of their cooperative interactions.

Integrating ANSYS Fluent Simulation and Aspen Plus for efficient heavy metal ion removal with de-oiled cake

In this study bio-flocculant extracted from the de-oiled cake, a common waste generated while producing oil was used to treat an electroplating industrial effluent. A comprehensive analysis of flocculation efficiency in a simulated reactor using ANSYS Workbench - Fluent, with a focus on optimizing impeller position was carried out. The findings reveal that the optimal impeller position is 2 cm from the tank base, where maximum turbulent kinetic energy (0.02577 m2/s2) and dissipation rate (22.19 m2/s3) were achieved at 200 RPM, enhancing flocculation efficacy. Furthermore, the study identifies 0.5 g L−1 as the optimal flocculant dosage, resulting in 72.70 % and 89.38 % removal of Ni(II) and Cr(VI), respectively. The flocculation process was determined to follow second-order kinetics, with significant improvements in collision efficiency and particle aggregation at the optimized dosage. Fourier Transform Infrared spectroscopy analysis confirmed chemical interactions leading to flocculation, while zeta potential and particle size distribution studies corroborated the stability and effectiveness of the process. A techno-economic analysis was conducted, estimating the total capital investment required for pilot and industrial-scale implementations, highlighting the feasibility and scalability of the proposed treatment method. A holistic framework for enhancing industrial effluent treatment processes by integrated computational fluid dynamics, kinetic studies, and economic evaluation, is the novelty of this research.

Chitosan enriched with ZnO[sbnd]nanoparticles fabricated using Synadenium glaucescens (Pax) aqueous leaf extract maintains postharvest quality of banana

Applications of edible coatings containing metallic nanoparticles for the preservation of post-harvest fruit quality have emerged as one of the most preferable strategies because of their enhanced antimicrobial properties. In the current study, zinc oxide nanoparticles were synthesized using Synadenium glaucescens leaf extract and added to chitosan for the post-harvest quality preservation of banana. The synthesized zinc oxide nanoparticles (ZnOSydlNPs) were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental dispersive x-ray (EDX) and X-ray diffraction (XRD) techniques. The nanoparticles were found to form large particles due to aggregations of small particles of an average size of 11 ± 4 nm. The coating solution containing a mixture of chitosan and zinc oxide nanoparticles exhibited higher antimicrobial effects against Escherichia coli, Staphylococcus aureus, Puccinia asparagi and Candida albicans compared to chitosan. The inhibition diameters of chitosan and chitosan-ZnOSydlNPs against E. coli were 6 and 15 mm, respectively. Similarly, the average inhibition diameters of chitosan, chitosan-ZnOSydlNPs (0.1%) and chitosan-ZnOSydlNPs (0.3%) against Staphylococcus aureus, Puccinia asparagi and Candida albicans were 10 ± 2, 15 ± 0.5 and 16 ± 3 mm, respectively. The banana coated with chitosan-ZnOSydlNPs solutions exhibited higher titratable acid (maleic) than control and chitosan-coated samples. Additionally, banana coated with chitosan-ZnOSydlNPs films showed lower total soluble solids, weight loss and ripening index compared to chitosan-coated and control samples. The findings from the current study indicated that ZnOSydlNPs incorporated in polymeric materials (chitosan) could serve as a potential preservative of post-harvest qualities for banana and related fruits.

Plasmonic Ag Nanoparticles: Correlating Nanofabrication and Aggregation for SERS Detection of Thiabendazole Pesticide.

The level of aggregation and aggregate morphology of metallic nanoparticles are factors that influence the SERS signal (surface-enhanced Raman scattering), affecting reproducibility and sensitivity. This study presents a systematic evaluation of the colloidal aggregation on the SERS signal by combining transmission electron microscopy and UV-vis extinction spectroscopy. It focuses on the effect of two methods of sample preparation ("external standard method-ESM" and "standard addition method-SAM") on the SERS signal using the fungicide thiabendazole (TBZ) in Ag colloid as a probe molecule. The TBZ critical concentration (concentration for which SERS reaches the maximum intensity) was 6.0 × 10-6 mol/L for ESM and 1.5 × 10-6 mol/L for SAM. Besides, TBZ exhibited a sigmoid-type isotherm for ESM, indicating formation of a TBZ first layer on Ag nanoparticles at lower concentrations (Ag aggregates more compact; size <500 nm) and TBZ multilayers at higher concentrations (Ag aggregates more branched; >2 μm). For SAM, the TBZ first layer formation was also observed at lower concentrations (Ag aggregates more branched; <2 μm). However, at higher concentrations, the Ag colloid degradation/precipitation was observed (Ag aggregates more compact; >2 μm). The Ag aggregation mechanisms align with reaction-limited colloidal aggregation at lower concentrations and diffusion-limited colloidal aggregation at higher concentrations. We believe these results contribute to the SERS research field despite all of the work already done over its 50-year history.