Ethanol Solution Research Articles

Genistein and Aphid Probing Behavior: Case Studies on Polyphagous Aphid Species

(1) Background: Genistein is a naturally occurring flavonoid with a rich spectrum of biological activities, including plant-herbivore interactions. The aim of the study was to evaluate the effect of exogenous application of genistein on aphid behavior during probing in plant tissues. (2) Methods: Vicia faba, Brassica rapa ssp. pekinensis, and Avena sativa were treated transepidermally with a 0.1% ethanolic solution of genistein, and the probing behavior of generalist aphid species Aphis fabae, Myzus persicae, and Rhopalosiphum padi was monitored on their respective treated and untreated host plants using electropenetrography (=electrical penetration graph technique, EPG); (3) Results: Genistein did not deter aphid probing activities in non-phloem tissues. In A. fabae and R. padi, a trend towards reduction and in M. persicae a trend towards increase in phloem sap ingestion occurred on genistein-treated plants, but these trends were not statistically significant. (4) Conclusions: Genistein is not a deterrent chemical against generalist aphid species studied; therefore, it is not recommended for practical application.

The Formation Mechanism of Zein Gel Induced by Amyloid-like Fibrils

The preparation of zein gels often leads to unstable product quality due to poor reproducibility, posing substantial challenges for the food industry and biomedical applications. Thus, it is essential to study the gelation mechanism and key factors responsible for gelation. Herein, we report four types of assembled structures from zein solutions in binary ethanol–water solvents with either a high concentration (30% w/v) and a low concentration (5% w/v), namely, spheres, spheres with tangential structures, amyloid-like fibrils, and sub-agglomerates with crystal structures. The tangential structure at the edges of the spheres was first observed by transmission electron microscopy (TEM) at the initial stage, offering a model for studying protein folding and aggregation mechanisms. By observing the gelation processes with TEM for morphology, cryo-TEM to confirm structure preservation, HR-TEM for fine details, and negatively stained TEM to reveal hidden features, along with small-angle X-ray scattering (SAXS), we identified two types of gels: one was mainly network structures formed by sphere–sphere fusion, which was thermoreversible, and the other one was irreversible gel due to the increase in the amount of amyloid-like fibrils. Results show that the existence of thermoreversible zein gels indicates potential effective regulation tools of zein gel properties. In addition, amyloid-like fibrils were first isolated from native zein. During amyloid-like fibril formation, the number of tangential structures increased considerably, which were composed of thinner fibrils. High-resolution TEM showed a substructure with a 0.35 nm interplanar spacing, providing evidence of β-sheet aggregates also as confirmed by SAXS. This unique substructure has not been reported in other edible proteins. Moreover, understanding the fibrillation mechanism of zein provides a basis for controlling and developing novel food structures for food protein function and offers insights into neurodegenerative diseases.

Hydrophobic ion pairing as a novel approach to co-axial electrospraying of peptide-PLGA particles

Electrospraying is a processing technique that has gained much interest to prepare polymeric particles. The technique operates at ambient temperature, thereby avoiding heat induced degradation of labile therapeutics (e.g. peptides and proteins). Exposure to organic solvents can be minimised by co-axial electrospraying through separation of core (aqueous) and shell (organic) solvents. However, aqueous solutions are often difficult to electrospray due to high surface tension. Immiscibility between the core–shell solvents creates a further process challenge. Herein, we describe for the first time the use of hydrophobic ion pairing (HIP) to encapsulate a polypeptide into polymeric particles prepared by co-axial electrospraying. Peptide ion pairs were prepared to incorporate a model peptide – teriparatide – into an organic solvent, permitting facile electrospraying while also protecting the peptide from denaturation. Teriparatide loaded PLGA particles were generated by electrospraying from aqueous or ethanolic peptide solutions (core). A PLGA solution in chloroform (with and without co-solvents) was employed as the shell solution. The aqueous core solution led to a teriparatide encapsulation efficiency of 79.2 ± 19.8 %, which was not significantly different from the ethanolic core (57.1 ± 14.5 %). When aqueous solutions were used the process lacked reproducibility, resulting in low process yields (61.3 ± 4.0 %). In contrast, when an organic core was used a dry powder bed was achieved with a yield of 102.2 ± 8.8 %. The peptide’s integrity and biological functionality were retained after electrospraying as ion pairs, as evidenced in a cell-based PTH1R receptor binding assay.

Dandelion inspired multi-functional superhydrophobic bamboo scrimber with desirable humidity resistance

Bamboo scrimber is high value added biomass fiber composites from natural bamboo due to its excellent multiple properties. However, the hydrophilicity of bamboo scrimber make it being susceptible to mold, fungi decay, colour changing and cracking during outdoors application. Therefore, wind blowing dandelion inspired multi-functional superhydrophobic bamboo scrimber was fabricated by spraying solution of Cu2O nanoparticles (NPs) modified phenol formaldehyde (PF) resin, immersing ethanol solution of stearic acid, followed by growth of copper stearate nanowires. The superhydrophobic bamboo scrimber exhibited desirable chemical and mechanical durability, liquid permeability, ultraviolet resistance, self-cleaning and anti-fouling properties, as well as mold resistance. More importantly, the modified bamboo scrimber performed best humidity resistance over 136 days under relative humidity of 85 % in this field, which can be attributed to the dense nanostructure of copper stearate nanowires. Furthermore, a specific bamboo cellulose crystalline model from natural bamboo to bamboo scrimber was firstly proposed to support the improvement of hardness. This work provide an biomimetic strategy for bamboo scrimber superhydrophobic modification, and it’s also innovative to promote the high value development of biomass composites.

Extraction of Fucoxanthin from Marine Organisms and Its Therapeutic Effect on Cancer Cells

As China’s economy develops and its population grows, resources are becoming increasingly scarce. As a result, attention is shifting towards utilising marine resources, and the ability to process them is an increasingly important area of development.Within the traditional marine industry, kelp is primarily used for fucoidan extraction, with other substances such as kelp pigments often cast off as waste. Fucoxanthin constitutes the major carotenoid component found within kelp pigments. These pigments are believed to possess immunomodulatory, anti-inflammatory, and anti-tumour properties, and are of multifaceted benefit to human health by counteracting cellular oxidative damage induced by free radicals. Kelp served as the raw material in this study. Macroporous resin was utilized to extract Fucoxanthin from the kelp extract. Only an aqueous ethanol solution was employed for the extraction process. Subsequently, reduced-pressure column chromatography was conducted to quickly enrich the Fucoxanthin. Finally, the anti-tumour activity and free radical scavenging ability of the Fucoxanthin were analyzed. The results of the experiment revealed that Fucoxanthin can be effectively adsorbed by X-5 resin and its adsorption capability is robust. Additionally, using a 60% concentration of ethanol solution can promptly and effectively elute the absorbed Fucoxanthin from the X-5 resin. Moreover, after incubation for 48 hours at a concentration of 80 μg/mL of Fucoxanthin, the expression levels of p65, p52, and p50 genes significantly decreased in cancer cells. Fucoxanthin, a pigment found in kelp, exhibits potent antioxidant activity. The findings suggest that Fucoxanthin possesses the ability to effectively suppress the expression of cancer cells and scavenge free radicals.

Nanoscale Poly(Dopamine)‐Modified ZIF‐8 Particle Hybrid Solvent‐Resistant Thin Film Nanocomposite (TFN) Membranes via Interfacial Polymerization on a Robust Polyether Ether Ketone (PEEK) Substrate

ABSTRACTThis study introduces an innovative approach to fabricating a poly ether ketone (PEEK)‐based thin‐film nanocomposite (TFN) nanofiltration membrane. Ultrafine polydopamine (PDA) modified zeolitic imidazolate framework‐8 (ZIF‐8) nanoparticles were integrated into the polyamide (PA) layer through a process of interfacial polymerization. The impacts of PDA@ZIF‐8 nanoparticle loading on composite membranes were examined, and their separation performances with different solvents and small molecular organics with various molecular weights and charges were evaluated. The PDA modification is credited with inducing a thinner, less crosslinked PA layer, culminating in the formation of a selective barrier that is both loose and ultra‐thin, improving the separation capabilities of membranes. The TFN‐3 membrane, with a 0.01 wt% loading of PDA@ZIF‐8 nanoparticles, emerged as a standout, demonstrating notably enhanced hydrophilicity. The pure water and organic solvent permeances through the TFN‐3 membrane were remarkably enhanced, with recorded values of 6.19 ± 0.26 L h−1 m−2 bar−1 for pure water and 3.44 ± 0.21 L h−1 m−2 bar−1 for methanol. Furthermore, the TFN‐3 membrane showcased impressive molecular retention in ethanol solutions for compounds with a molecular weight cut‐off (MWCO) of 464 g/mol. The PEEK‐based TFN‐3 membrane also exhibited exceptional creep resistance, ensuring consistent performance during long‐term testing. In a 5‐day ethanol separation test, the TFN‐3 membrane maintained a Rose Bengal (RB) retention rate exceeding 99%, underscoring its stability and reliability. The newly developed PEEK‐based TFN membrane not only promises robust solvent resistance and stability but also delivers efficient separation and purification capabilities. It holds great potential for offering effective and sustainable solutions across a spectrum of industries, particularly in pharmaceutical production and chemical processing, where the separation, recovery, and purification of solvents are paramount.

Non-contact measurement method of liquid composition using microwave radar cross-section

This study aims to provide a non-contact detection of liquid composition inside containers using Microwave Radar Cross-section (RCS) measurement technology. Firstly, it analyzes the limitations of traditional near-infrared spectroscopy methods and proposes the necessity of introducing microwave detection methods. The research demonstrates through experiments a significant correlation between polar substances like total acid content and radar scattering capability, showing microwave radar’s effectiveness in reflecting the polarity characteristics of liquids. Furthermore, theoretical derivations and experimental validations illustrate that differences in electromagnetic properties of different liquid components lead to variations in echo loss, thereby impacting RCS levels. Experimental results indicate that microwave radar RCS measurement technology achieves an accuracy level of 2%, capable of distinguishing between different concentrations of ethanol, acetic acid, and other solutions. This study highlights the significant advantages of microwave radar RCS measurement technology in non-contact detection of liquid composition, providing new methods and a technological foundation for precise liquid component detection.

Flavonoids from Ougan (Citrus suavissima Hort. ex Tanaka) peel exert hypoglycemic potency through inhibiting insulin resistance in HepG2 cells and regulating gut microbiota in diabetic mice

To fully and value-addedly utilize the citrus peel resource, flavonoids were extracted and purified from peel powder of Ougan (Citrus suavissima Hort. ex Tanaka) using an ultrasonic assisted ethanol solution extraction method and AB-8 macroporous resin purification. The obtained flavonoid extract from peel of Ougan (FEPO) was used for the hypoglycemic experiments in vitro and in vivo on glucose consumption in insulin resistance model HepG2 cells and streptozotocin induced diabetes model mice. A significant reduction of glucose consumption in the model cells while a significant increase in the treated were found in a dose-dependent manner, compared to 5.2241 ± 0.2201 mmol/L of the normal cells (P < 0.05). When the FEPO concentration was 80 μg/mL, the cell glucose consumption was 4.4055 ± 0.1772 mmol/L. Compared with those in the model group (diabetic mice), the fasting blood glucose in the FEPO intervened mice was significantly decreased (P < 0.05). FEPO intervention caused decreased levels of TC, TG, LDL-C, and increased HDL-C and insulin contents in the serums as well as ameliorative histopathology of the liver, kidney, and pancreas in diabetic mice. FEPO improved the gut microbiota structure of diabetic mouse by regulating its composition, especially significantly increasing the relative abundance of Lactobacillus, Ileibacterium, unclassified_f_Lachnospiracea, Romboutsia, norank_f_Muribaculaceae, Faecalibaculum and Coriobacteriaceae_UCG-002 (P < 0.05), while decreasing that of norank_f_norank_o_Clostridia_UCG-014, Lachnospiraceae_NK4A136_group and Candidatus_Saccharimonas. In conclusion, FEPO had good hypoglycemic efficacies both in vitro and in vivo as well as gut microbiota regulating effect.

Ammonium Oxathioamidate

Ammonium oxathioamidate (1) was synthesised by the reaction between O-ethyl-thioxamate (oxalic acid-1-amide-2-O-ethyl ester) and ammonium hydrogen carbonate in water solution. Compound 1 was fully characterised by both microanalytical (elemental analysis, melting point determination) and spectroscopic means (FT-IR and NMR spectroscopy). Crystals suitable for single-crystal X-ray diffraction were isolated by slow evaporation of an ethanol solution of the compound. The analysis of the crystal packing reveals the prominent role exerted by intermolecular hydrogen bonding (HB) and chalcogen bonding (ChB) interactions.

Shelf life extension of ‘’Gyros'’ pork meat using plant extracts with antioxidant and antimicrobial activities

The aim of the present study was to estimate the shelf life of ‘’Gyros'’ pork meat (GPM), during storage under refrigeration. Raw (R) (control sample), marinated (M), and treated samples with green coffee (GC), turmeric (T) and ginger (G) extracts with ethanol solution of grape origin were subjected to microbiological, physicochemical, and sensory analyses. Results showed that TVC and Pseudomonads in R, M, and G treated samples reached 7 log CFU/g on day 4, whereas Enterobacteriaceae remained <6 log CFU/g throughout storage. T and GC samples had TVC and Pseudomonads populations <7 log CFU/g on day 6 and day 8, respectively, and Enterobacteriaceae populations <6 log CFU/g. Furthermore, the ethanolic extracts of GC and T showed antibacterial activity against Salmonella Typhimurium and Staphylococcus aureus. The ethanolic extracts exhibited also high antioxidant activity against DPPH free radical, indicating lower TBARS and mercaptans content values, whereas delayed the decrease in heme iron during refrigerated storage compared to the R samples. Sensory analysis showed that treated samples had a special and acceptable taste. Based on the obtained results, the shelf life of R, M and G treated GPM was 4 days, while samples treated with T and GC had an increased shelf life by 2 and 4 days, respectively.

Influences of Coagulant Polarity on the Modulus of the Chitin Hydrogel.

The chitin hydrogel draws great attention in biomedical fields owing to its high similarity and good affinity for peptides. The conversion of raw chitin to the designed hydrogel through a sol-gel process prevails, while the modulus of the chitin hydrogel is significantly influenced by the factors of gelation technology (i.e., coagulation, involving polymer chain rearrangement and the reconstruction of multiple interactions). Water and several organic solvents such as ethanol, DMAc, and DMSO are effective coagulants for aqueous chitin/KOH/urea solutions. In particular, the concentration of aqueous ethanol solutions displays a high dependency on the modulus of chitin hydrogels. However, recent reports about chitin hydrogel fabrication seldom demonstrate the effect of coagulant factors on hydrogel performance. Our study found that the polarity of the coagulant and its diffusion index for entry into the chitin solution during the coagulation process had a direct influence on the hydrogel modulus. The influence of the two factors was investigated to find out their quantified relationship with the hydrogel modulus, which will inspire a practical method to develop new coagulants to prepare modulus-manipulable chitin hydrogels.

Исследование проницаемости эпителиального слоя клеток TEER методом

The study investigated the electrical characteristics of the Caco-2 cellular layer grown on a cellulose acetate membrane using impedance spectroscopy and cyclic voltammetry methods. The effect of ethanol solutions of varying concentrations on the electrophysical properties of the cellular layer was studied. During measurements of the layer characteristics by the cyclic voltammetry method under direct current, it was found that its resistance before ethanol treatment was 642 kOhm. Treatment with a 25% ethanol solution increased this value to 645 kOhm, while 50% and 95% solutions decreased it to 505 kOhm and 373 kOhm, respectively. During the study of the cellular layer's properties using impedance spectroscopy with alternating current, dependencies of the real and imaginary parts of the resistance on the ethanol concentration in the treatment solution were obtained. The obtained data were used to construct Nyquist diagrams. Their analysis allowed for the proposal of an equivalent circuit describing the process of current flow through the studied system. The equivalent circuit included parameters of paracellular transport, membrane resistance and capacitance, as well as elements accounting for electrode polarization. As a result, values of capacitance and membrane layer resistance were obtained. It was established that the membrane layer capacitance changes under the influence of ethanol. When treated with a 50% ethanol solution, capacitance increases, indicating degradation of the cell membrane and a reduction in its barrier function. Treatment with a 95% solution led to a decrease in capacitance, which can be attributed to the compression of the cell layer, reducing the capacitance contribution to the system's overall conductivity. The results demonstrate the importance of quantitative analysis of cellular electrical parameters for studying their response to chemical stress and confirm the potential of such approaches in biomedicine for creating sensors and «organ-on-a-chip» systems.

AQbD-enhanced green RP-UPLC-PDA methodology for quantification and forced degradation studies for omeprazole, amoxicillin, and rifabutin

The ternary combination like omeprazole (OMP), amoxicillin (AMX), and rifabutin (RFB) was approved by the FDA in November 2019 for combating Helicobacter pylori infections and ulcers caused by this infection. This study aims to develop and authenticate a robust and eco-friendly RP-UPLC technique aimed at the concurrent analysis of OMP, AMX, and RFB, following ICH guidelines, Analytical Quality by Design (AQbD), and green analytical chemistry (GAC) principles. The analysis used the Thermo C18 column (100 mm × 2.1 mm, 1.7 µm), ethanol, and formic acid solution (43:57) as mobile phase with a flow rate of 0.2 ml/min at 272 nm. The method was developed based on the ICH Q14 and validated according to ICH Q2(R1) followed by Forced degradation studies under various conditions. The method showed good linearity for OMP, AMX, and RFB, with coefficient of determination (r2) of 0.9995, 0.9993, and 0.9997, respectively. Precision studies indicated low %RSD values, confirming high reproducibility. Forced degradation studies confirmed the stability of the drugs for 30 min in acid, base, and redox reactions, and they were also stable for 6 h at 105 °C in dry conditions. GAPI assessment depicted a green and yellow pictogram, AGREE scored 0.85, BAGI scored 80, and RGB12 Whiteness Assessment Tool scored 97.5%. The developed RP-UPLC-PDA technique is robust and reliable for the concurrent quantification of the triple combination. It aligns with sustainability goals, enhancing the efficiency and environmental sustainability of pharmaceutical analysis, and setting a benchmark for future analytical methods.

Development of Antioxidant-Active Sericin-Curcumin-Loaded Sodium Alginate/Polyvinyl Alcohol Films Crosslinked with Calcium Chloride as a Promising Wound Dressing Application.

Silk sericin (SS) and curcumin (Cur) possess significant antioxidant properties, making them highly beneficial for wound healing applications. This study aimed to develop SS-Cur-loaded sodium alginate/polyvinyl alcohol (SA/PVA) films crosslinked with calcium chloride, creating a biomaterial with enhanced stability and antioxidant properties. Wound dressings containing SS-Cur were fabricated by mixing SA and PVA at different ratios of 1:1, 1:2, 1:4, and 1:6. The resulting films were then crosslinked with calcium chloride in an ethanol solution to enhance film integrity. These films were characterized using several techniques, revealing that the presence of ethanol in calcium chloride affected film properties, including the gel fraction, swelling, film thickness, and FTIR analysis. The presence of ethanol in calcium chloride revealed the highest drug content in the SA/PVA films. In vitro release studies demonstrated sustained release of SS-Cur from all formulations. Cytotoxicity and antioxidant activity tests showed that SS-Cur-loaded SA/PVA films with ethanol in calcium chloride increased cell viability and enhanced antioxidant effects in L929 cells. In conclusion, this study demonstrates that the presence of ethanol in the crosslinking solution improved the functionality of SS-Cur-loaded SA/PVA films, making them promising candidates for wound healing and soft tissue regeneration.

Novel Peptide Analogues of Valorphin-Conjugated 1,8-Naphthalimide as Photodynamic Antimicrobial Agent in Solution and on Cotton Fabric.

For the first time, N-modified analogues of VV-hemorphin-5 (Valorphin) were synthesised and conjugated with three different 4-substitured-1,8-naphthalimides (H-NVal without substituent, Cl-NVal with chloro-substituent, and NO2-NVal with nitro-substituent). Cotton fabric was modified with these peptides by soaking it in their ethanol solution, and the colourimetric properties of the obtained fabric were measured. The fluorescent analysis shows that peptide immobilisation on a solid matrix as fabric decreases the molecule flexibility and spectrum maxima shift bathocromically with the appearance of a vibrational structure. The peptides' contact antimicrobial activity, and the resulting fabrics, have been investigated against model Gram-positive B. cereus and Gram-negative P. aeruginos bacteria. For the first time, the influence of light on bacterial inactivation was investigated by antibacterial photodynamic therapy of similar peptides. Slightly more pronounced activity in liquid media and after deposition on the cotton fabric was obtained for the peptide containing 4-nitro-1,8-naphthalimide compared to the other two peptides. Immobilisation of a peptide on the surface of fibres reduces their antimicrobial activity since their mobility is essential for good contact with bacteria. Cotton fabrics can be used in medical practice to produce antibacterial dressings and materials.

Synthesis of New 1,4-Naphthoquinone Fluorosulfate Derivatives and the Study of Their Biological and Electrochemical Properties.

This study presents the synthesis of new fluorosulfate derivatives of 1,4-naphthoquinone by the SuFEx reaction. Anticancer properties of obtained compounds were studied on PC-3 (prostate adenocarcinoma), SKOV-3 (ovarian cancer), MCF-7 (breast cancer), and Jurkat cell lines. All the studied compounds showed higher cytotoxic effects than Cisplatin. The DFT method was applied to determine the electronic structure characteristics of 1,4-naphthoquinone derivatives associated with cytotoxicity. A method of determination of 2,3-dichloro-1,4-naphthoquinone (NQ), 3-chloro-2-((4-hydroxyphenylamino)-1,4-naphthoquinone (NQ1), and 4-((3-chloro-1,4-naphthoquinon-2-yl)amino)phenyl fluorosulfate (NQS) in a pharmaceutical substance using an impregnated graphite electrode (IMGE) was developed. The morphology of the IMGE surface was studied using scanning electron microscopy (SEM). The electrochemical behavior of NQ, NQ1, and NQS was studied by cyclic voltammetry (CV) in 0.1 M NaClO4 (96% ethanol solution) at pH 4.0 in a potential range from -1 to +1.2 V. Electrochemical redox mechanisms for the investigated compounds were proposed based on the determining main features of the electrochemical processes. Calibration curves were obtained by linear scan voltammetry in the first derivative mode (LSVFD) with the detection limit (LOD) 7.2 × 10-6 mol·L-1 for NQ, 8 × 10-7 mol·L-1 for NQ1, and 8.6 × 10-8 mol·L-1 for NQS, respectively.

Modeling, simulation, and optimization of multi-stage equilibrium extraction of phenolic compounds from grape pomace

The seasonal nature of wine production results in the accumulation of significant quantities of grape pomace (GP) during harvest, presenting management challenges for wineries that traditionally regard this solid byproduct as low-value waste. However, extracting phenolic compounds (PCs) from GP offers a promising avenue for creating bioactive extracts for use in the food, pharmaceutical, and cosmetic industries. This study develops a mathematical model for predicting the total phenolic content (TPC) and total dissolved solids (TDS) in liquids obtained from multi-equilibrium-stage extraction processes using a 50% aqueous ethanol solution to recover PCs from Tannat GP. The model is applicable across a wide range of TPC and TDS concentrations in the liquid (0.2–45.4 gGAE/L for TPC and 1–118 g/L for TDS) and extraction temperatures between 30 and 70 °C. It is used to determine the optimal operational conditions of a Shanks extraction system, either to minimize fresh solvent consumption or to maximize selectivity for PCs extraction, achieving a desired extraction yield with a specified number of extraction vessels.

The Formation of Porous Silicon Using Vertical Photoelectrochemical Method with Laser Energy Variation

Due to its notable characteristics, porous silicon (PSi) has become the main focus in silicon upgrades for optoelectronics, medical, and sensor applications. Here, successful vertical photoelectrochemical fabrication of PSi based on crystalline silicon n-type wafers with orientation (100) has been accomplished. Silicon surfaces were anodized for 10 min in a solution of hydrofluoric acid and ethanol at a ratio of 1:3 and a current density of 4 mA/cm2 under laser illumination. Illumination sources were red, green, and purple laser beams with energies of 1.91 eV, 2.33 eV, and 3.06 eV, respectively, conducted to observe the effects on PSi microstructures and optical properties. The pores formed on the silicon surface were characterized via SEM, XRD, FTIR, and UV-Vis DRS Spectrophotometer. SEM analysis showed pore size distributions of 2.130, 3.353, and 1.078 mm for PSi samples with red, green, and purple lasers, respectively. XRD investigation revealed diffraction angles of 33.14° and 69.47° belonging to (211) and (422) planes, respectively, corresponding to the PSi. For samples of silicon and PSi with red, green, and purple lasers, the crystallite size and crystallinity were 168.55 nm and 44.80%, 25.02 nm and 17.12%, 29.19 nm and 23.56%, and 145.05 nm and 35.17%, respectively. FTIR observation confirmed that the PSi surface contained chemical bonds of Si-Si, Si-H, Si-H2, Si-O-Si, and C=O. UV-Vis DRS examination revealed the reflectance spectrum oscillation, indicating that lasers caused pore formation in PSi with bandgap energies of between 1 and 2 eV.

Electronic Synergistic Effects on the Stability and Oxygen Evolution Reaction Efficiency of the Mesoporous LiMn2-xMxO4 (M = Mn, Fe, Co, Ni, and Cu) Electrodes.

Stable porous manganese oxide-based electrodes are essential for clean energy generation and storage because of their high natural abundance and health safety. This investigation focuses on mesoporous LiMn2-xMxO4 (where M is Fe, Co, Ni, and Cu and x is 0, 0.1, 0.3, 0.5, and 0.67) electrodes and thin/thick films. The mesoporous electrodes and films are fabricated by coating clear and homogeneous ethanol solutions of the salts (LiNO3, [Mn(OH2)4](NO3)2, and [M(OH2)x](NO3)2) and surfactants (P123 and CTAB) and calcining at elevated temperature (denoted as F-LiMn2-xMxO4, G-LiMn2-xMxO4, and meso-LiMn2-xMxO4, respectively). The electrochemical properties, stability, and oxygen evolution reaction (OER) performance of the F/G-LiMn2-xMxO4 electrodes are investigated in alkaline media using a three electrode setup. The F-LiMn1.33M0.67O4 electrodes (where M is Mn, Fe, Co, and Ni) exhibit low Tafel slopes of 60, 43, 44, and 32 mV/dec, respectively. While all the Mn-rich and F-LiMn2-xFexO4 electrodes degrade via Mn(VI) disproportionation reaction, the 33% Co electrode shows high stability during the OER. The nickel-based electrodes are stable with as little as 15% Ni and display excellent OER performance over 25% Ni, albeit undergoing a transformation that accumulates Ni(OH)2 species on the electrode surface. Copper in the F-LiMn2-xCuxO4 electrodes is homogeneous at low Cu percentages but forms a CuO phase above 15% Cu, undergoes degradation, and displays a weak OER performance. In short, Co and Ni stabilize the F-LiMn1.33Co0.67O4 and F-LiMn1.7Ni0.3O4 electrodes, which display excellent OER performance.

Growth of Surface Oxide Layers on Dendritic Cu Particles by Wet Treatment and Enhancement of Sinter-Bondability by Using Cu Paste Containing the Particles

Pastes were prepared using dendritic Cu particles as fillers, and a compression die attachment process was implemented to establish a pure Cu joint using low-cost materials and high-speed sinter bonding. We aimed to grow an oxidation layer on the particle surface to improve sinter-bondability. Because the growth of the oxidation layer by general thermal oxidation methods makes it difficult to use as a filler owing to agglomeration between particles, we induced oxidation growth by wet surface treatment. Consequently, when the oxidation layer was appropriately grown by surface treatment using an acetic acid–ethanol solution, we obtained an improved joint strength, approximately 2.8 times higher than the existing excellent result based on a bonding time of 10 s. The joint formed in just 10 s at 300 °C in the air under 10 MPa compression showed a shear strength of 28.4 MPa. When the bonding time was increased to 60 s, the joint exhibited a higher strength (35.1 MPa) and a very dense microstructure without voids. These results were attributed to the acceleration of sintering by the in situ formation of more Cu nanoparticles, which effectively reduced the increased oxide layers in the particles using a reducing solvent.