Decreasing Particle Size Research Articles

Study on the Characteristics of Fine Rice Flour by Micro-Crushing and Its Effects on the Quality Improvement of Rice Cakes

To investigate the impact of micro-crushing technology on rice flour characteristics and its enhancement of rice cake quality, resting angle, slip angle, solubility, water-holding capacity, emulsification, oil absorption, gelatinization, and baking quality, rice flour and rice cakes were analyzed using a texture analyzer and a gelatinization instrument. The results indicated that a decrease in particle size led to a significant increase in damaged starch from 18% to 26.5%. Both the resting angle and slip angle increased, indicating reduced fluidity. The gelatinization temperature decreased from 76.63 °C to 71.61 °C, the gelatinization time was reduced from 6.6 min to 6.4 min, and gelatinization viscosity initially increased and then decreased. Water-holding capacity increased 1.0-fold with decreased particle size, and solubility increased 11.6-fold together with the increase temperature. Emulsification and oil absorption were optimal when the particle size exceeded 120–140 mesh. The conductivity of the rice flour suspension rose with decreased particle size, while the conductivity of rice flour paste and cake batter decreased. Decreased particle size led to significantly reduced rice cake hardness and chewiness of 47.77% and 52.44%, while elasticity, restoration, specific volume, and porosity increased 18.75%, 15.15%, 31.16% and 25.10%, respectively. The skin and core color darkened with reduced luminosity, correlating with enhanced sensory scores. Correlation analysis revealed that physiochemical properties of rice flour influenced gelatinization properties, thereby affecting rice cake quality. This study provides a foundation for utilizing fine rice flour in rice cakes.

Comparative analysis of the antimicrobial activity and dye degradation of metal oxides (TiO2, CdO, Mn2O3, and ZnO) nanoparticles using a green approach.

A tremendous amount of recent work has been done on different metal oxide nanomaterials for biological activities and photocatalytic dye degradation. This work used the Cissus quadrangularis leaf extract to prepare TiO2, CdO, Mn2O3, and ZnO nanoparticles using a green synthesis approach. To ascertain the physicochemical characteristics of the generated metal oxide nanoparticles, various characterisation techniques were used. The X-ray diffraction technique was used to determine the composition of the crystal and phase. Metal oxide nanoparticles have been proven to be present through surface morphological investigations using a scanning electron microscope and energy dispersive spectroscopy analysis. UV-Vis and Fourier transform infrared spectra were used for spectroscopic analysis. X-ray photoelectron spectroscopy can determine a material's elemental composition in addition to the electronicand chemicalstates of its atoms. The nanomaterial's distinct morphology, which resembles rods, rose petals, platelets, and spheres, was discovered by scanning electron microscope. Synthesized metal oxide nanoparticles have demonstrated a remarkable efficiency of 87.5-90.6% when utilized as a catalyst towards the removal of the malachite green dye under UV light irradiation. Additionally, we use the disc diffusion method to assess antibiotic efficacy against Bacillus subtilis, Candida tropicalis, and Escherichia coli. ZnO nanoparticles had the greatest zones of inhibition for 80 μL doses, measuring 26.99mm for Bacillus subtilis, 27.57mm for Escherichia coli, and 25.28mm for Candida tropicalis. The antimicrobial activity was strongly impacted by the size of the nanoparticles and increased with decreasing particle size. Overall, our research demonstrates that metal oxide nanoparticles are a promising photocatalytic agent for wastewater treatment and biological applications.

Formulation and Assessment of Tolnaftate Microsponges for Topical Medication Deliverance

Objective: This study aimed to develop and evaluate the sustained delivery of Tolnaftate using topical polymeric microsponges. Materials and Methods: Tolnaftate-loaded microsponges made of ethyl cellulose were prepared via quasi-emulsion solvent diffusion. The effects of the drug-to-polymer ratio on active drug content, particle size, and entrapment efficiency were examined. The optimized formulation was incorporated into a Carbopol gel and evaluated for drug content, pH, viscosity, and in vitro drug release. The study considered internal phase volume, stirring rate, and emulsifier concentration as variables and analyzed their impact on entrapment efficiency and particle size. Results: Increasing stirring speed reduced particle size and improved entrapment efficiency, while a higher volume of dichloromethane decreased particle size. Scanning electron microscopy revealed porous and spherical microsponges. The 1.5:1 drug-to-polymer ratio yielded the highest active drug content, optimal entrapment efficiency, and smallest particle size, making it the preferred ratio for further studies. Conclusions: The drug release from the microsponge gel was more sustained compared to both the marketed product and pure drug gel. An ex vivo drug deposition study using rat abdominal skin showed satisfactory drug deposition. These polymeric microsponges show potential as a topical drug delivery system for antifungal therapy.

Unique features of plasmonic absorption in ultrafine metal nanoparticles: unity and rivalry of volumetric compression and spill-out effect

Abstract We present a solution to a longstanding challenge in nanoplasmonics and colloid chemistry: the anomalous optical absorption of noble metal nanoparticles in the ultrafine size range of 2.5–10 nm, characterized by a rapid long-wavelength shift in plasmon resonance as the particle size increases. Our investigation delves into the impact of alterations in electron density along the radial direction of nanoparticles and the resulting variations in dielectric constants on the spectral positioning of the plasmon resonance. We explore the interplay of the spill-out effect, volumetric compression, and their combined impact in different experimental conditions on electron density variation within the particle volume and its blurring at the particle boundary. The latter effectively forms a surface layer with altered dielectric constants and a size-independent extent. As particle size decreases, the influence of the surface layer becomes more pronounced, especially when its extent is comparable to the particle radius. These findings are specific to ultrafine plasmonic nanoparticles and highlight their unique properties.

Effect of Silver Nanoparticle Size on Antibacterial Activity

The ubiquitous use of products containing AgNPs results in the entry of nanoparticles into the environment. Both nanoparticles and Ag+ released upon their oxidative dissolution have a toxic effect on living microorganisms. The antibacterial activity of spherical silver nanoparticles of 10.8 ± 0.8 nm and 22.7 ± 2.2 nm in size stabilized by carbonate ions was studied against Escherichia coli and other bacteria. The biocidal action of silver increases as the particle size decreases. Analysis of these results and other known data made it possible to substantiate a linear proportional relationship between the minimum inhibitory concentration (MIC) or the half-maximal inhibitory concentration (IC50) and silver nanoparticle size and determine empirical parameters for this relationship. The antibacterial activity (toxicity) is directly proportional to the specific surface area of nanosized silver.

High-intensity ultrasound modification of techno-functional and structural properties of white finger millet protein fractions.

In this study, albumin, globulin, and glutelin were extracted from white finger millet, and their amino acid content, functional and structural properties were investigated. The protein concentration of albumin, globulin, and glutelin were 76.01%, 74.32%, and 69.55%, respectively. The results showed that all the fractions had a significant amount of essential amino acids. Aqueous protein dispersions (10%, w/v) were treated for 12min at different ultrasound power levels (100, 200, and 300W). The solubility, emulsifying, and foaming properties of albumin and glutelin were significantly (p<0.05) improved after ultrasound treatment (20kHz) which indicates that ultrasound could unfold protein aggregates. A decrease in particle size, increase in surface hydrophobicity, and zeta potential correlated with improved functional properties. Ultrasound treatment reduced the size of all proteins except for fractions at 300W and also sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a significant change in the molecular weight of albumin and glutelin at 300W. Scanning electron microscopy of treated protein fraction showed distinctive microstructure with irregular structure compared to untreated protein fraction. Although Fourier transform infrared spectroscopy spectra of proteins were similar after ultrasonication, a partial increase in the intensity of the Amide A band was observed. In conclusion, the ultrasound-treated protein fraction can be used as a high-value plant-based emulsifier.

Impact of Ligand Concentration on the Properties of Nucleic-Acid-Encapsulated MOFs and Inflammation Modulation in Prostate Cancer Cells.

The zeolitic imidazolate framework (ZIF) is one of the most explored metal-organic-framework-based systems for nucleic acid delivery to cancer cells. Current nucleic acid delivery tools exhibit several drawbacks, such as high manufacturing costs, endosomal entrapment, toxicity, and immunogenicity. However, the biomimetic mineralization of Zn-based ZIFs offers a low-cost and facile encapsulation of nucleic acids at room temperature in aqueous conditions. The efficiency of nucleic acid delivery and its subsequent impact on inflammation in cells are influenced by the physicochemical properties of the material. The imidazole content determines the formation and crystallinity of ZIF, and an optimal ratio ensures the formation of well-defined and highly crystalline structures. In this study, a series of siRNA-encapsulated ZIFs (siRNA@ZIF) were systematically prepared by varying ligand-to-metal (L/M) molar ratios. Our study demonstrates that variations in ligand concentrations influence the crystalline structures, particle size, and shape of siRNA@ZIF particles. At low L/M, two-dimensional siRNA@ZIF particles form with a size of 1 μm. As the L/M ratio increases gradually, the particle size decreases, resulting in three-dimensional particles ∼200 nm in size. We also observed better stability of siRNA@ZIF in water prepared using high L/M values and time-dependent cellular uptake by the cells. Additionally, no significant impact of the biocomposites on inflammation was found, indicating the lack of an unwanted immune response and nonimmunotoxic nature over longer periods (96 h). These findings highlight the necessity of fine-tuning ligand concentrations and synthesis chemistry in designing efficient and optimal ZIF-based systems as versatile delivery platforms for nucleic acids.

Engineering sodium alginate microparticles with different crystallinities for niclosamide repositioning and solubilization to improve solubility and oral bioavailability in rats

Niclosamide is a commonly used anthelmintic; however, its poor aqueous solubility limits its oral bioavailability. Enhancing its solubility and oral bioavailability is crucial for its repositioning as an anticancer agent. Here, we aimed to develop new sodium alginate–poloxamer microparticles with different crystallinities to increase drug solubility and oral bioavailability. Sodium alginate and poloxamer were used as the polymer and surfactant, respectively, to prepare niclosamide-loaded microparticles via spray drying. The optimized amorphous and crystalline microparticles were prepared with niclosamide/sodium alginate/poloxamer weight ratios of 1:2.5:3 and 1:1.125:0.375, respectively. Their solubilities, dissolution rates, physicochemical properties, and oral bioavailabilities were compared with those of drug powder in rats. Physicochemical characterization of the developed particles revealed changed structure from crystalline to amorphous, with no irregular crystalline characteristics but decreased particle size. Compared to the pure drug powder, crystalline microparticles retained their crystalline nature with no significant changes in particle size. Both microparticles showed significantly higher aqueous solubilities, dissolution rates, and oral bioavailabilities than niclosamide powder in rats. Amorphous microparticles showed higher solubility (approximately 1775-fold) and oral bioavailability (approximately 5.6-fold) than niclosamide powder due to the crystalline-to-amorphous change and decreased particle size. The developed amorphous microparticles can be used to improve niclosamide solubility and oral bioavailability.

Biocompatible Pickering emulsions and films: Unlocking the chitosan-polyvinyl alcohol synergy for multifaceted capabilities

The exciting potential of harnessing the synergy between polysaccharides and bioactive components is attracting significant scientific interest. This research paves the way for the development of novel materials that can improve human health. Therefore, current research is conducted to explore the innovative use of chitosan, polyvinyl alcohol (PVA) complex (CHN-PVA), olive oil-stabilized Pickering emulsions (PEs), and films with multifaceted applications. The sonication stabilized Pickering emulsions (PEs at different pH values 3, 5, 7, 9, and 11) exhibited decrease in particle size compared to control PEs. The pH significantly impacted the zeta potential of PEs. Fourier-transform infrared spectroscopy (FTIR) confirmed the non-covalent linkages. The antibacterial activity of the PEs revealed greater efficacy against gram-positive bacteria than gram-negative bacteria. The CHN-PVA synergy greatly impacted the mechanical properties of films, resulting in tremendous increase of tensile strength and elongation at break compared to CHN film. The PEs efficiently delivered quercetin at neutral pH. The electro spraying of PEs significantly extended strawberry shelf life. Finally, the films exhibited promising properties of adsorbent and the results depicted that pH had a significant impact on methylene blue removal. Conclusively, this investigation underscores the potential of CHN-PVA films in food, health, and environmental fields.

Lactobacillus plantarum LP1 Fermentation Effects on Aegle marmelos Mucilage: Physicochemical, Structural, and Bioactive Properties

Fermentation is a promising technique for altering the structure of fruit mucilage, leading to enhanced health benefits. In this study, we explored the impact of fermenting Aegle marmelos mucilage using Lactobacillus plantarum LP1 on its physicochemical, structural, and bioactive properties. The findings revealed a decrease in total sugar (39.45±0.23% to 34.67±0.45%) and glucuronic acid content (20.80±0.31% to 14.34±0.37%) post-fermentation, while protein content increased (1.80±0.32% to 2.14±0.24%). In addition, fermented mucilage exhibited a decrease in particle size (178.4±5.06 to 146.3±4.18nm), more negative zeta potential (−16.4±1.13mV to −25.31±1.15mV), and higher solubility (89.36±1.69 to 92.13±1.42%) compared to non-fermented mucilage. Structural characterization revealed alterations in surface morphology, but minimal changes in the fundamental mucilage structure were observed. Additionally, fermented mucilage showed an increased ability to scavenge free radicals and stimulate macrophages to secrete NO and IL-6 in RAW 264.7 cells compared to non-fermented mucilage. Overall, the findings suggest that fermentation with Lactobacillus plantarum LP1 can improve the functional properties and bioactivities of bael fruit mucilage, thereby enhancing its potential applications in various industries.

Melting-dissolving kinetics and mechanism of high silica-alumina coal ash particles deposited to liquid slag wall in entrained flow gasification

The depositing and subsequent physicochemical behaviors of coal ash particles to the liquid slag wall in an entrained flow gasifier are essential to the wall reaction, slag flow and discharge. In this study, the melting-dissolving behavior and kinetics of high silica-alumina ash on the typical molten slag surface were investigated at a particle scale through in-situ melting experiments. The multifactorial effect on the ash fusibility was further evaluated. Experimental results revealed that the presence of molten slag significantly reduced the melting temperatures of high silica-alumina ash particles, with an initial melting temperature of around 1270 ℃. Dissolvability was linearly correlated with temperature, and the melting rate increased with increasing temperature or decreasing particle size. However, complete melting was difficult to achieve at 1400 ℃. Consequently, the effect of adding flux (CaO) in the molten slag on the ash fusibility was further evaluated. The ash particles achieved complete melting at a 4 wt% CaO addition, and the flux addition increased the melting rate and solubility. Besides, the mechanism-level explanation of the melting-dissolving process showed that Ca ion migration led to the transformation of aluminum to higher coordination sites, which destabilized the silica-aluminium tetrahedra structure and manifested in the generation of Bytownite macroscopically. Comparative analysis showed the melting rate depended on the diffusion process, and the melting-dissolution kinetics was established to predict the dissolution rate, which could provide a reference for the slag discharge of coals with high ash fusion temperatures in the industry.

Effects of interaction between wheat bran dietary fiber and gluten protein on gluten protein aggregation behavior.

Effects of wheat bran dietary fiber (WBDF) as a nutritional additive on flour products quality mainly depends on the interaction between WBDF and gluten protein. In this study, the effects and mechanisms of WBDF with different particle sizes and additive amounts on gluten protein aggregation behavior were investigated. The results showed that the addition of WBDF led to a decrease in free sulfhydryl content, particle size, molecular weight and gluten macromer (GMP) content, an increase in zeta potential and SDS-extractable protein content, and a deterioration in the gluten network morphology compared to the control group, suggesting that the aggregation behavior of gluten protein was inhibited. When WBDF was added at 3 % and 6 %, dilution effect, mechanical shear, steric hindrance, and non-covalent binding were the main mechanisms leading to depolymerization. Further addition of WBDF (9 %, 12 %) inhibited the depolymerization of gluten protein due to competitive hydration and non-covalent binding. However, when WBDF was added at 15 %, the dilution effect, mechanical shear and steric hindrance of WBDF (88 μm < particle size<150 μm) dominated, and their inhibitory of aggregation induced the formation of a loose gluten network structure. In contrast, the weaker mechanical shear and steric hindrance effects of WBDF (particle size<88 μm) mitigated the degradation of gluten network structures by WBDF.

Two-ways regulation of the emulsion gel properties of curdlan by dry ball milling treatment and their relationships with the microstructures, emulsification characteristics and gel properties of ball milled curdlan

Ball milling treatment could affect the microstructures, improve the emulsification properties of curdlan (CL) and regulate the emulsion gel properties of CL based emulsion gel in two-ways. With increasing ball milling time (1 h–8 h), the particle size first decreased and then increased, the relative crystallinity decreased, and the contact angle increased. Ball milled curdlan (BMCL)-6 h showed the best emulsifying property and stability, which was the combined effects of decreased particle size and increased hydrophobic property. Ball milling 1 h and 2 h significantly improved the hardness and chewiness of CL-based emulsion gels, while, ball milling 4 h–8 h could make the emulsion gels much softer and ice cream-like. When the emulsion gels were heated twice consecutively, the visual appearance and texture properties did not change significantly, indicating the excellent thermal stability of these emulsion gels. The BMCL based emulsion gel with adjustable gel properties and good thermal stability has a wide range of uses in the food system.

The Effect of Dihydromyricetin (DMY) on the Mechanism of Soy Protein Isolate/Inulin/Dihydromyricetin Interaction: Structural, Interfacial, and Functional Properties.

The combination of proteins with polysaccharides and polyphenols is expected to improve their physicochemical and functional properties. In this study, a novel plant-based antioxidant emulsifier was formed by soybean protein isolate (SPI), inulin (INU), and dihydromyricetin (DMY). Based on the binary system of SPI/INU, we focused on exploring the effect of the DMY concentration (0.5 mg/mL~2.5 mg/mL) on the formation and properties of the ternary complex. The structure, interaction mechanism, and interfacial and functional properties of the ternary complex were investigated. The results indicate that compared to the SPI/INU binary complex, the SPI/INU/DMY ternary complex had a significant decrease in particle size (~100 nm) and a slight decrease in absolute zeta potential. The SPI/INU binary complex with DMY mainly interacted by hydrogen bonding and hydrophobic interactions. Due to the incorporation of DMY, the structure of SI was denser and more flexible. The ternary complex exhibited an ideal three-phase contact angle and demonstrated better foaming and antioxidant ability. Additionally, compared to SPI/INU, the ternary complex had a significant improvement in EAI. These results provide a strategy for polyphenols to modify the structure, interfacial properties, and functions of protein/polysaccharide complexes. This provides a potential reference for the preparation of more ternary complexes with excellent emulsifying and antioxidant properties for application in emulsions.

Plasma-induced aging of microplastics and its effect on mercury transport and transformation

Microplastics are known to adsorb heavy metals, with aged microplastics exhibiting greater adsorption capacity. This study investigates the impact of microplastic aging on the transport and transformation of mercury (Hg), a highly toxic heavy metal. Polystyrene (PS) and polyvinyl chloride (PVC) were aged using plasma treatment to simulate environmental conditions. Characterization of virgin and plasma-treated microplastics revealed aging mechanisms induced by plasma treatment. Notably, aged PS, unlike PVC, did not show a decrease in particle size but exhibited a decrease in specific surface area, likely due to chain cleavage and re-polymerization of polystyrene fragments, and thermal effects during plasma treatment. Both aged PS and PVC demonstrated increased hydrophilicity, enhanced negative charge, and a higher presence of nitrogen- and oxygen-containing functional groups. These changes were correlated with a significant increase in Hg adsorption capacity. Density functional theory (DFT) calculations further indicated that the adsorption of Hg2+ by microplastics is promoted by the presence of oxygen- and nitrogen-containing functional groups. The particularly strong influence of nitrogen-containing functional groups on Hg2+ adsorption was confirmed through both experimental and theoretical approaches. Adsorption kinetics and isothermal experiments, along with X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analyses, were conducted to elucidate the Hg adsorption mechanism of on microplastics before and after aging. The mechanisms involved include pore filling, van der Waals’ forces, electrostatic interactions, hydrophobic interactions, and functional group complexation. The intraparticle diffusion model indicated that adsorption is controlled by multiple steps. Importantly, the surface functional groups of aged microplastics can reduce Hg2+ to Hg+ and adsorb it, suggesting a more complex adsorption process for Hg on aged microplastics. This study provides a scientific basis for understanding microplastic aging and the Hg adsorption mechanism on microplastics, highlighting the complex dynamics of combined microplastic and heavy metal contamination.

Size effect of ZIF-8 based nanocarrier pesticide delivery system on targeted release and insecticidal activity.

Traditional chemical pesticides are easily lost by surface runoff and only small quantities reach the target, thus causing serious environmental pollution. In this work, dinotefuran@zeolitic imidazolate framework-8@polydopamine@zein (DNF@ZIF-8@PDA@zein), was constructed to deliver DNF with pH and enzyme double response of release, thereby achieving targeted release and efficient long-term pest control. DNF@ZIF-8@PDA@zein was synthesized with three hydrated diameters (249.73 ± 9.99 nm, 142.94 ± 5.63 nm and 75.16 ± 4.66 nm, respectively). The release of DNF from DNF@ZIF-8@PDA@zein after 28 h was significantly higher at pH 5.0 (89.22 ± 7.18%) compared to that at pH 8 (81.8 ± 6.11%). Protease-assisted release of DNF was notably higher than that without protease (pH 5: 89.22 ± 5.55% versus 27.19 ± 3.22%; pH 8: 81.8 ± 6.11% versus 25.39 ± 3.87%). The stimuli-responsive release of DNF from DNF@ZIF-8@PDA@zein increased with decreased particle size due to increased pore size, reduced binding forces (i.e., weaker π-π stacking, hydrogen bonding, and Zn-N covalent bonding), and the shortening of diffusion path, leading to faster disintegration and drug release. Additionally, the anti-photolysis ability of DNF@ZIF-8@PDA@zein was 3.2 times that of pure DNF. The insecticidal activity improved with smaller nanoparticles due to higher drug release rate and greater inhibition of detoxification enzyme activity by more zinc ion (Zn2+) dissolution. The pH and enzyme dual-responsive release as well as insecticidal activity of DNF@ZIF-8@PDA@zein increase with decreased nanoparticle size, showing effective pest management in long-term and potential application prospects in sustainable agriculture. © 2024 Society of Chemical Industry.

Effect of Particle Size on Physical Properties, Dissolution, In Vitro Antioxidant Activity, and In Vivo Hepatoprotective Properties of Tetrastigma hemsleyanum Diels et Gilg Powders

Objective: The aim of this study was to analyze the effects of different particle sizes of Tetrastigma hemsleyanum Diels et Gilg (TDG) powders on physical properties, dissolution, in vitro antioxidant activity, and in vivo hepatoprotective properties. Methods: The particle size of TDG coarse powders (TDG-CP), TDG fine powders (TDG-FP), and TDG micro powders (TDG-MP) were measured by a laser particle size analyzer. The physical properties were measured according to the latest version of the Chinese Pharmacopoeia (Committee Chinese Pharmacopoeia 2020). The content of the total flavonoids, total polysaccharides, kaempferol-3-O-rutinoside, and rutin of TDG powders were determined using the NaNO2-Al (NO3)3 colorimetric method, the sulphate-phenol colorimetric method, and HPLC, respectively. In vitro dissolution and antioxidant activity were determined by the paddle method in phosphate buffer (pH 6.8) and the DPPH radical scavenging method, respectively. In addition, the liver tissue pathology was evaluated by hematoxylin and eosin staining (H&amp;E), and the AST and ALT activities were measured by automatic biochemical analyzer. The superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) activities were measured by using commercial analysis kits. Results: As the particle size decreases, the fluidity of TDG powders decreased and the porosity increased. In addition, there were no significant differences in physical properties between low temperature pulverized powders and room temperature pulverized powders. The final dissolution rates of the four bioactive ingredients in TDG-MP were found to be 85.06%, 85.61%, 83.88%, and 83.26%, respectively, whereas in TDG-CP, the dissolution rates were significantly lower at 18.79%, 17.96%, 22.46%, and 24.35%. The EC50 values of TDG-CP, TDG-FP, and TDG-MP on DPPH scavenging activity were 0.82, 0.31, and 0.10 mg/mL, respectively. The AST and ALT activities of the TDG-FP group and the TDG-MP group were significantly decreased and the SOD, CAT, and GSH activities were significantly increased when compared with that of the model group. The inflammatory cell infiltration and vacuolar degeneration of liver cells in the TDG-FP group and the TDG-MP group were significantly improved. Conclusions: The particle size of TDG powders had a significant effect on the physical properties and in vivo bioactivity. TDG pulverized to a fine particle size or smaller is a promising approach for clinical applications with improved physicochemical and biological properties.

Mechanisms of hardness enhancement in CrB2 thin films with varying VB2 concentrations

Transition metal borides are well-known for their high hardness, excellent wear resistance, chemical inertness, and electrical conductivity, making them promising for a wide range of applications. Understanding the interconnections between material structure, composition, and mechanical properties is essential for designing and synthesizing effective coatings. This study systematically investigates the structural and mechanical properties of CrB₂ thin films with varying concentrations of VB₂ (0–10 wt%), focusing on structure, hardness, elastic behavior and deformation characteristics mechanisms through atomic force microscopy and nanoindentation measurements. The results show that increasing VB₂ content leads to the formation of island cluster structures, which significantly strengthens atomic bonds and, in turn, enhances the hardness of the thin films. As particle size decreases, the higher proportion of surface atoms and increased surface energy have a more pronounced effect on the mechanical properties. In particular, the addition of VB₂ up to 10 wt% in CrB₂ thin films results in a marked improvement in superhard properties. 26 % increase in hardness value is also influenced directly by the changes in Young's modulus and Poisson's ratio that depend on the VB₂ concentration.

Recovery of Selenium-Enriched Polysaccharides from Cardamine violifolia Residues: Comparison on Structure and Antioxidant Activity by Different Extraction Methods.

The residues from selenium-enriched Cardamine violifolia after the extraction of protein were still rich in polysaccharides. Thus, the recovery of selenium polysaccharides (SePSs) was compared using hot water extraction and ultrasonic-assisted extraction techniques. The yield, extraction rate, purity, specific energy consumption, and content of total and organic selenium from different SePS extracts were determined. The results indicated that at conditions of 250 W (ultrasonic power), 30 °C, and a liquid-to-material ratio of 30:1 extracted for 60 min, the yield of SePSs was 3.97 ± 0.07%, the extraction rate was 22.76 ± 0.40%, and the purity was 65.56 ± 0.35%, while the total and organic selenium content was 749.16 ± 6.91 mg/kg and 628.37 ± 5.93 mg/kg, respectively. Compared to traditional hot water extraction, ultrasonic-assisted extraction significantly improves efficiency, reduces energy use, and boosts both total and organic selenium content in the extract. Measurements of particle size, molecular weight, and monosaccharide composition, along with infrared and ultraviolet spectroscopy, revealed that ultrasonic-assisted extraction breaks down long-chain structures, decreases particle size, and changes monosaccharide composition in SePSs, leading to lower molecular weight and reduced dispersity. The unique structure of SePSs, which integrates selenium with polysaccharide groups, results in markedly improved antioxidant activity and reducing power, even at low concentrations, due to the synergistic effects of selenium and polysaccharides. This study establishes a basis for using SePSs in functional foods.

Study on UV-VIS characteristics of Aluminum Zinc Oxide nanoparticles through manganese substitution using Wemple-Di domenico method and diffuse reflectance spectroscopy

In this research Manganese-substitution impact on linear and nonlinear (NL) optical properties of Aluminum-doped ZnO (AlZnO) Nanoparticles (NPs) are investigated. Utilizing measured data of reflectance acquired from the DRS, the higher-order NL optical characteristics of the provided NPs are examined. The maximum quantity of NL susceptibility χ3 is measured to be around 3.945 × 10−10 esu at wavelength λ = 520 nm and 7.467 × 10−11 esu at wavelength λ = 530 nm for AlZnO and Manganese-substituted Aluminum-doped Zinc-Oxide (Mn-also) NPs, for particle sizes 14−67 nm and 11−54 nm, consecutively. Consequently, the synthesis method (sol–gel) which is used in this work concluded a decrease in particle size and different optical behavior especially in UV spectral regions during the substitution with Manganese in comparison with the AlZnO. This decrement assures that a decrease in the size of crystallite induces a decline in the χ3. The obtained optical parameters are red shifted with the Manganese substitution. Also, the NL absorption coefficient (β c(m/W)) is enhanced in the UV range. The maximum of the NL absorption coefficient (β c(m/W)), for AlZnO and Mn-AlZnO NPs, are determined (at λ = 250 nm) 2.24 × 10−18 (m/W) and 5.76 × 10−15 (m/W) respectively.