Search Results (214)

MIL-101(Cr), a widely studied chromium-based metal–organic framework material consisting of chromium metal ions and terephthalic acid ligands, has attracted much attention due to its ultra-high specific surface area, large pore size, and excellent thermal, chemical, and aqueous stability. The outstanding properties and abundant unsaturated Lewis acid sites of this material have shown promising applications in aqueous phase adsorption, gas storage, separation, catalysis, drug delivery, and sensing. In this paper, we systematically review the synthesis technology and performance optimization strategy of MIL-101(Cr), discuss the advantages and limitations of various synthesis methods, such as traditional hydrothermal method, microwave-assisted hydrothermal method, template method, and solvent-thermal method, and summarize and analyze the optimization strategy of MIL-101 from the aspects of physical modification and chemical modification. In addition, this paper summarizes the latest application progress of MIL-101(Cr) in gas adsorption and separation, wastewater purification, pollutant removal, catalysis, and pharmaceutical delivery, and points out the current challenges and future development directions, to provide guidance and inspiration for the industrial application of MIL-101(Cr) and the development of new materials. Full article

Several new coumarin–isoxazole–pyridine hybrids were synthesized through a 1,3-dipolar cycloaddition reaction of nitrile oxides, prepared in situ from pyridine aldehyde oximes, with propargyloxy- or propargylaminocoumarins in moderate-to-good yields. Synthetic modifications were applied using (diacetoxyiodo)benzene (PIDA) at room temperature, microwave irradiation, or tert-butyl nitrite (TBN) under reflux. Coumarin, isoxazole, and pyridine groups were selected for hybridization in one molecule due to their biological impact to inhibit lipid peroxidation and an enzyme implicated in inflammation. Preliminary in vitro screening tests for lipoxygenase (LOX) inhibition and anti-lipid peroxidation for the new hybrids were performed. A discussion on the structure–activity relationship is presented. Compounds 12b and 13a were found to be potent LOX inhibitors with IC₅₀ 5 μΜ and 10 μΜ, respectively, while 12b presented high (90.4%) anti-lipid peroxidation. Furthermore, hybrids 12b and 13a exhibited moderate-to-low anticancer activities on HeLa, HT-29, and H1437 cancer cells. Full article

This study investigated the effects of physical field protein modification methods on the mechanical properties, color, rehydration performance, thermal stability, and sensory quality of yuba. The results showed that all three modification methods shortened the drying time of yuba, and each method enhanced the tensile strength and thermal stability of yuba. Yuba treated with microwave–vacuum for 10 min demonstrated the best performance in terms of tensile strength, elongation, color, and overall sensory score, making it the optimal method for the physical field modification of yuba. In addition, microwave–vacuum treatment led to better rehydration performance, thermal stability, and a faster rehydration rate. Through the analysis of the microstructure of yuba as well as its protein secondary and tertiary structures, it was found that microwave–vacuum treatment can maintain the tissue network structure of yuba while promoting more heat-induced protein conformational changes, showing a greater increase in the content of β-sheets, which contribute to enhancing the tensile strength and water-holding capacity of yuba, thereby improving its product quality. Full article

Hydrothermal carbonization (HTC) is a novel thermochemical process that turns biomass into hydrochar, a substance rich in carbon that has potential uses in advanced material synthesis, energy production, and environmental remediation. With an emphasis on important chemical pathways, such as dehydration, decarboxylation, and polymerization, that control the conversion of lignocellulosic biomass into useful hydrochar, this review critically investigates the fundamental chemistry of HTC. A detailed analysis is conducted on the effects of process variables on the physicochemical characteristics of hydrochar, including temperature, pressure, biomass composition, water ratio, and residence time. Particular focus is placed on new developments in HTC technology that improve sustainability and efficiency, like recirculating process water and microwave-assisted co-hydrothermal carbonization. Furthermore, the improvement of adsorption capacity for organic contaminants and heavy metals is explored in relation to the functionalization and chemical activation of hydrochar, namely through surface modification and KOH treatment. The performance of hydrochar and biochar in adsorption, catalysis, and energy storage is compared, emphasizing the unique benefits and difficulties of each substance. Although hydrochar has a comparatively high higher heating value (HHV) and can be a good substitute for coal, issues with reactor design, process scalability, and secondary waste management continue to limit its widespread use. In order to maximize HTC as a sustainable and profitable avenue for biomass valorization, this study addresses critical research gaps and future initiatives. Full article

We propose a distinct mechanism to explain the matter–antimatter imbalance observed in the universe, rooted in quantum entanglement asymmetry (QEA). Our concept of QEA differs from its usage in the recent literature, where it typically measures how much symmetry is broken within a subsystem of a larger quantum system. Here, we define QEA as an intrinsic asymmetry in the entanglement properties of particle–antiparticle pairs in the early universe, leading to a preferential survival of matter over antimatter. We develop a theoretical framework incorporating QEA into the standard cosmological model, providing clear justification for the asymmetry in entangled states and corresponding modifications to the Hamiltonian. Numerical simulations using lattice Quantum Chromodynamics (QCD) demonstrate that QEA can produce a net baryon asymmetry consistent with observations. We also predict specific signatures in Cosmic Microwave Background (CMB) anisotropies and large-scale structure formation, offering potential avenues for empirical verification. This work aims to deepen the understanding of cosmological asymmetries and highlight the significance of quantum entanglement in the universe’s evolution. Full article

To investigate the structure–antioxidant activity relationship, Pleurotus ferulae polysaccharides were extracted using ultrasonic (U-PFPS) and microwave/ultrasonic-assisted methods (MU-PFPS). Compared to U-PFPS with a molecular weight of 1.566 × 10³ kDa, MU-PFPS exhibited a lower molecular weight of 89.26 kDa. In addition, unlike U-PFPS, which is primarily composed of glucose (Glu:Man:Gal = 91.1:3.5:5.4), MU-PFPS has a more balanced composition of Glu:Man:Gal in the ratio of 39.4:27.8:32.8 and contains more branched chains. Furthermore, antioxidant analysis revealed that high concentration (at concentrations above 600 μg/mL) MU-PFPS demonstrated stronger protective effects against oxidative damage in RAW264.7 cells than U-PFPS did. Collectively, these data suggest that lower molecular weight and higher branching degree of polysaccharides at appropriate concentrations may correlate with enhanced antioxidant enzyme activities. Our work provides a method for isolating polysaccharides with higher antioxidant activity and offers insights into the structure–activity relationship of polysaccharides, laying the foundation for future applications in polysaccharide modification and structural characterization. Full article

This study examined the effects of varying microwave treatment durations (0–120 s) on the structural and functional properties of glycosylated soybean 7S protein. The results indicated that microwaving for 60 s significantly altered the structure of 7S, resulting in a more ordered protein configuration. The treated protein exhibited the largest particle size (152.3 nm), lowest polydispersity index (0.248), highest α-helix content (47.86%), and lowest β-sheet, β-turn, and random coil contents (12.33%, 16.07%, and 22.41%, respectively). It also showed the lowest endogenous fluorescence and surface hydrophobicity, and the highest thermal denaturation temperature (76.8 °C). Additionally, microwaving for ≤90 s led to increased peptide modifications, with carbamylation and deamidation being the most prevalent. A microwave treatment time of 60 s also notably enhanced the functional properties of glycosylated soybean 7S protein, optimizing water-holding capacity (6.060 g/g), emulsification activity, and stability (45.191 m²/g and 33.63 min). The foaming capacity was second only to the 120 s treatment (32% at 60 s versus 34% at 120 s), though the oil-holding capacity (22.73 g/g) and foaming stability (33.42%) were significantly lower than those of the controls. Microwave treatment durations exceeding or below 60 s led to the structural disintegration of the protein, diminishing most of its functional properties. This study explores the mechanism of how microwave processing time affects the structure and functional properties of glycosylated soybean 7S protein and identifies 60 s as the optimal microwave processing time. It meets the demands for healthy and delicious food in home cooking, providing scientific evidence for using microwave processing technology to enhance the nutritional value and quality of food. Full article

To reduce the adverse effects of bran on whole wheat flour products. In this study, seven reconstituted whole wheat flours were prepared and used to determine the effects of microwave and steam treatment on bran. We aimed to understand the effect of modification treatment on the properties of reconstituted whole wheat flour and dough. Treatment with whole wheat flour had a significant impact on the color, solubility, and swelling. As the cooking time increased, the initial temperature (To), peak temperature (Tp), and final temperature (Tc) of pasting and enthalpy (Hp) decreased. The combination of microwave and steam modification increased water absorption and stabilization time, leading to improved fermentation performance and cooking stability of the dough. The modified whole wheat flour and dough exhibited a significant decrease in crystallinity, possibly due to the degradation of the crystalline and amorphous regions of the starch granules during heat treatment. Upon modification treatment, the spiral β-turn structure was transformed into an irregular curled and β-sheet structure, and the β-sheet ratio increased significantly (p < 0.05). The modification of bran through microwave treatment (700 W for 30 s) followed by steam treatment (10 min) enhanced the processing performance of reconstituted whole wheat flour, offering substantial potential for the development of novel products and the optimization of industrial production efficiency. Full article

Conducting polymers represent a crucial class of functional materials with widespread applications in diverse fields. Among these, poly(3,4-ethylenedioxythiophene) (PEDOT) and its derivatives have garnered significant attention due to their distinctive optical, electronic, and magnetic properties, as well as their exceptional tunability. These properties often exhibit intricate interdependencies, manifesting as synergistic, concomitant, or antagonistic relationships. In optics, PEDOTs are renowned for their high transparency and unique photoelectric responses. From an electrical perspective, they display exceptional conductivity, thermoelectric, and piezoelectric performance, along with notable electrochemical activity and stability, enabling a wide array of electronic applications. In terms of magnetic properties, PEDOTs demonstrate outstanding electromagnetic shielding efficiency and microwave absorption capabilities. Moreover, these properties can be precisely tailored through molecular structure modifications, chemical doping, and composite formation to suit various application requirements. This review systematically examines the mechanisms underlying the optoelectromagnetic properties of PEDOTs, highlights their tunability, and outlines prospective research directions. By providing critical theoretical insights and technical references, this review aims to advance the application landscape of PEDOTs. Full article

This study evaluated the potential usage of phosphorylated egg white protein (P-EWP) nanogels fabricated via microwave-induced phosphorylation modification and gel process and further ultrasonic nanometrization as novel delivery systems for cinnamon bark essential oil (CBEO). Compared to EWP-CBEO nanogels without chemical phosphorylation, the obtained P-EWP-CBEO nanogels have shown smaller average hydrodynamic diameter (133.6 nm), relatively uniform size distribution (polydispersity index around 0.265), enhanced negative surface charge (−35.4 mV), and improved stability under the conditions of high temperature (up to 90 °C) and ionic strength (up to 200 mM NaCl). Moreover, P-EWP-CBEO nanogels, with hydrophobic interactions and disulfide bonds as the main intermolecular forces, exhibited a remarkable conformational change in microstructures. In addition, the results of the antibacterial experiments on Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes showed that the MIC values of P-EWP-CBEO nanogels were two times lower than those of EWP-CBEO nanogels and could completely inhibit the growth of pathogenic bacteria within 108 h. Hence, we have suggested that P-EWP-CBEO nanogels are successfully fabricated with improved physicochemical properties as novel potential natural preservatives in the food industry. Full article

The photocatalytic reduction of CO₂ to useful products is an area of active research because it shows a potential to be an efficient tool for mitigating climate change. This work investigated the modification of titania with copper(II) nitrate and its impact on improving the CO₂ reduction efficiency in a gas-phase batch photoreactor under UV–Vis irradiation. The investigated photocatalysts were prepared by treating P25-copper(II) nitrate suspensions (with various Cu²⁺ concentrations), alkalized with ammonia water, in a microwave-assisted solvothermal reactor. The titania-based photocatalysts were characterized by SEM, EDS, ICP-OES, XRD and UV-Vis/DR methods. Textural properties were measured by the low-temperature nitrogen adsorption/desorption studies at 77 K. P25 photocatalysts modified with copper(II) nitrate used in the process of carbon dioxide reduction allowed for a higher efficiency both for the photocatalytic reduction of CO₂ to CH₄ and for the photocatalytic water decomposition to hydrogen as compared to a reference. Similarly, modified samples showed significantly higher selectivity towards methane in the CO₂ conversion process than the unmodified sample (a change from 30% for a reference sample to 82% for the P25-R-Cu-0.1 sample after the 6 h process). It was found that smaller loadings of Cu are more beneficial for increasing the photocatalytic activity of a sample. Full article

The swift recombination of photo-induced electrons and holes is a major obstacle to the catalytic efficiency of TiO₂ nanomaterials, but the incorporation of graphene oxide and out-field modification is considered a potent method to augment photocatalytic properties. In this work, a series of GO/TiO₂ photocatalysts were successfully optimized by a microwave field. As determined by transient photocurrent response and electrochemical impedance spectroscopy (EIS) tests, microwave irradiation at 600 W for 5 min on the GO/TiO₂ photocatalyst promoted interfacial charge transfer and suppressed charge recombination. Through systematic characterizations, GT(600/5) exhibited the highest photooxidation rate (81.5%, 60 min) of Rhodamine B under visible light compared to other homologous samples, owing to the minimum grain size (16.914 nm), enlarged specific surface area (151 m²/g), maximum light response wavelength (510 nm), narrowest bandgap width (2.90 eV), and stronger oxidized hydroxyl radicals (•OH). Given the environmental friendliness, greenness, and sustainability, this study could present an efficient and economical strategy for synthesizing and fine-tuning photocatalysts. Full article

The paper presents the process of cellulose extraction from rice straw using water–alkaline solution treatment and the subsequent process of carboxymethylation of the obtained product when activated by microwave radiation. After mercerization of rice straw, the obtained product contained 89.2% cellulose and 6.7% lignin. The X-ray diffraction pattern of the obtained lignocellulose shows three diffraction peaks in the region typical for the polymorphic modification of cellulose Iβ (2θ = 15.50(78), 21.70(145), 34.70(52)). The degree of crystallinity was 65%. The product was heat-stable up to 247 °C. The synthesis of carboxymethylcellulose (CMC) based on the obtained product included successive processes of thermostating in alcohol–alkali solution and cellulose esterification reaction using monochloroacetic acid. To activate the carboxymethylation process, microwave radiation was used (350 W for 90 s), which made it possible to reduce the reaction time by more than 100 times. Functional group analysis of the carboxylated lignocellulose from rice straw was carried out using an FTIR spectrometer. In the IR spectra, a band with a maximum of 1742 cm⁻¹ was recorded, corresponding to stretching vibrations of >C(O)OH groups. The degree of polymerization was recorded by mass spectrometry. Full article

To enhance the pore structure of green coffee beans (GCB) and detect the sorption capacity and extraction characteristics of flavor compounds before roasting, this study employed several methods: hot air drying (HD), freeze-drying (FD), 3-levels short-time heating with puffing (SH₁P, SH₂P, and SH₃P), and 3-levels microwave with puffing (MW₄₅P, MW₆₀P, and MW₇₅P). These methods were applied to GCBs pre-soaked in water for different times. The effects of these treatments on color change, porosity, microstructure, citric acid sorption capacity, and caffeine and chlorogenic acid extraction yield were investigated. Results indicated that, except for GCBs treated with SH₁P, SH₂P, SH₃P, and MW₇₅P, all other modified GCBs showed minimal color change. GCBs treated with MW₆₀P exhibited favorable pore structures. MW₆₀P treatments significantly improved the extraction yield of caffeine and chlorogenic acid. Furthermore, the increased porosity and improved pore size distribution of GCB after MW₆₀P resulted in a significant increase in the sorption of citric acid onto modified GCB. The rate of the sorption reaction followed the pseudo-first-order kinetics. In conclusion, MW₆₀P are effective treatments for enhancing the microstructure of GCB, improving sorption capacity, and improving the extraction yield of flavor compounds. Full article

Microwaving has been used to qualitatively improve feed ingredients prior to including them in cattle feed. However, it is not known whether feed ingredients should be microwaved separately or in a mixture before being included in cattle feed concentrates. In the current study, the effects of the partial and full microwaving of high starch ingredients were investigated regarding their impact on the nutritional composition, physicochemical properties, and in vitro digestibility of feed concentrates. The cassava was microwave-irradiated before being mixed with other ingredients (MC, 35% of formulation). A microwave-cooked cassava–corn meal mixture (MCC, 45% of formulation) and a combination of all solid components (MSI, 96% of formulation) were also compared. A feed containing non-microwaved ingredients was formulated and served as the control (NM). Significantly altered proximate compositions and nutritive profiles were observed in all the microwaved components (p < 0.05). The observed modifications in pHs, water absorption capacities, thermal properties (differential scanning calorimetry), diffraction patterns (X-ray diffractometry), and microstructures (scanning electron microscopy) indicated enhanced enzymatic hydrolysis in vitro. A higher cellulase organic matter solubility and digestible organic matter were observed in the MCC and MSIs feeds relative to the control NM (p < 0.05). These findings indicate a combination of components could be added to feedstock before it is microwave processed to potentially include this pretreatment in the feed production process. Full article