Chemical Activation Research Articles

Study on the Anti-Inflammatory Mechanism of Coumarins in Peucedanum decursivum Based on Spatial Metabolomics Combined with Network Pharmacology.

Peucedanum decursivum (Miq.) Maxim (P. decursivum) is a traditional Chinese medicinal plant with pharmacological effects such as anti-inflammatory and anti-tumor effects, the root of which is widely used as medicine. Determining the spatial distribution and pharmacological mechanisms of metabolites is necessary when studying the effective substances of medicinal plants. As a means of obtaining spatial distribution information of metabolites, mass spectrometry imaging has high sensitivity and allows for molecule visualization. In this study, matrix-assisted laser desorption mass spectrometry (MALDI-TOF-MSI) and network pharmacology were used for the first time to visually study the spatial distribution and anti-inflammatory mechanism of coumarins, which are metabolites of P. decursivum, to determine their tissue localization and mechanism of action. A total of 27 coumarins were identified by MALDI-TOF-MSI, which mainly concentrated in the cortex, periderm, and phloem of the root of P. decursivum. Network pharmacology studies have identified key targets for the anti-inflammatory effect of P. decursivum, such as TNF, PTGS2, and PRAKA. GO enrichment and KEGG pathway analyses indicated that coumarins in P. decursivum mainly participated in biological processes such as inflammatory response, positive regulation of protein kinase B signaling, chemical carcinogenesis receptor activation, pathways in cancer, and other biological pathways. The molecular docking results indicated that there was good binding between components and targets. This study provides a basis for understanding the spatial distribution and anti-inflammatory mechanism of coumarins in P. decursivum.

Boosting mechanical properties of carbon fibers by gas-liquid dual-effect approach

The tensile strength and tensile modulus of existing carbon fibers (CFs) are 3 %–5 % of the theoretical values, which greatly limits the performance of CFs when used alone or as a reinforcing material. To increase the chemical reaction activity and roughness of the surface of CFs based on the enhancement of their mechanical properties, a comprehensive treatment of CFs was carried out by the gas-liquid dual-effect method. CFs were oxidized at high temperatures after immersion treatment using cobalt nitrate solution, and the effects of cobalt nitrate solution concentration, oxidation time, and calcination temperature on the surface morphology, functional groups, structural defects, and mechanical properties of CFs were investigated by the controlled-variable method. The results showed that when the concentration of cobalt nitrate solution was 0.2 molL-1, the calcination temperature was 200 °C, and the oxidation time was 4 h, the modification effect was the best. At this time, the tensile strength of CF is 6104.50 MPa, which is 40.35 % higher than that of the pure CF, and the tensile modulus is 378.56 GPa, which is 13.27 % higher than that of the pure CF, with a significant enhancement effect. It can offer feasible ideas for further research and development of CF composites, and provide an effective way to promote the industrialization of modified CFs for application.

Sustainable removal of tetracycline and paracetamol from water using magnetic activated carbon derived from pine fruit waste

This work presents highly porous magnetic activated carbon nanoparticles (MPFRC-A) derived from pine fruit residue. The MPFRC-A were produced through a three-step process: physical activation (carbonization temperature: 110–550 °C), chemical activation (H2SO4 (0.1 N, 96%)), and co-precipitation. These nanoparticles were then used to remove tetracycline (TC) and paracetamol (PC) from water. Functionalization with Fe3O4 nanoparticles on the surface of the pine fruit residue-derived activated carbon (PFRC-A) resulted in high saturation magnetization, allowing for separation from aqueous solution using an external magnet. The MPFRC-A adsorbent was characterized by Brunauer–Emmett–Teller (BET) analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Energy-dispersive X-ray spectroscopy (EDX) analyses, In the experimental section, the effects of various factors on the adsorption process were investigated, including pH, contact time, initial pollutant concentrations, adsorbent dosage, and temperature. Based on these investigations, adsorption isotherm models and kinetics were studied and determined. The results showed that MPFRC-A exhibited a large specific surface area (182.5 m2/g) and a high total pore volume (0.33 cm3/g). The maximum adsorption capacity was achieved at pH 6 and 5 for PC and TC drugs with an adsorbent dose of 400 mg and an initial concentration of 20 mg/L at 25 °C. The study revealed that the experimental data were well-fitted by the Langmuir isotherm model (R2 > 0.98), with maximum uptake capacities of 43.75 mg/g for TC and 41.7 mg/g for PC. Outcomes of the adsorption thermodynamics shows non-spontaneity of the reaction and the adsorption process by all adsorbents was endothermic.

Surface Treatment Strategies and Their Impact on the Material Behavior and Interfacial Adhesion Strength of Shape Memory Alloy NiTi Wire Integrated in Glass Fiber-Reinforced Polymer Laminate Structures.

Over the past few decades, there has been a growing trend in designing multifunctional materials and integrating various functions into a single component structure without defects. This research addresses the contemporary demand for integrating multiple functions seamlessly into thermoplastic laminate structures. Focusing on NiTi-based shape memory alloys (SMAs), renowned for their potential in introducing functionalities like strain measurement and shape change, this study explores diverse surface treatments for SMA wires. Techniques such as thermal oxidation, plasma treatment, chemical activation, silanization, and adhesion promoter coatings are investigated. The integration of NiTi SMA into Glass Fiber-Reinforced Polymer (GFRP) laminates is pursued to enable multifunctional properties. The primary objective is to evaluate the influence of these surface treatments on surface characteristics, including roughness, phase changes, and mechanical properties. Microstructural, analytical, and in situ mechanical characterizations are conducted on both raw and treated SMA wires. The subsequent incorporation of SMA wires after characterization into GFRP laminates, utilizing hot-press technology, allows for the determination of interfacial adhesion strength through pull-out tensile tests.

AKT-dependent nuclear localization of EPRS1 activates PARP1 in breast cancer cells

Glutamyl-prolyl-tRNA synthetase (EPRS1) is a bifunctional aminoacyl-tRNA-synthetase (aaRS) essential for decoding the genetic code. EPRS1 resides, with seven other aaRSs and three noncatalytic proteins, in the cytoplasmic multi-tRNA synthetase complex (MSC). Multiple MSC-resident aaRSs, including EPRS1, exhibit stimulus-dependent release from the MSC to perform noncanonical activities distinct from their primary function in protein synthesis. Here, we show EPRS1 is present in both cytoplasm and nucleus of breast cancer cells with constitutively low phosphatase and tensin homolog (PTEN) expression. EPRS1 is primarily cytosolic in PTEN-expressing cells, but chemical or genetic inhibition of PTEN, or chemical or stress-mediated activation of its target, AKT, induces EPRS1 nuclear localization. Likewise, preferential nuclear localization of EPRS1 was observed in invasive ductal carcinoma that were also P-Ser473-AKT+. EPRS1 nuclear transport requires a nuclear localization signal (NLS) within the linker region that joins the catalytic glutamyl-tRNA synthetase and prolyl-tRNA synthetase domains. Nuclear EPRS1 interacts with poly(ADP-ribose) polymerase 1 (PARP1), a DNA-damage sensor that directs poly(ADP-ribosyl)ation (PARylation) of proteins. EPRS1 is a critical regulator of PARP1 activity as shown by markedly reduced ADP-ribosylation in EPRS1 knockdown cells. Moreover, EPRS1 and PARP1 knockdown comparably alter the expression of multiple tumor-related genes, inhibit DNA-damage repair, reduce tumor cell survival, and diminish tumor sphere formation by breast cancer cells. EPRS1-mediated regulation of PARP1 activity provides a mechanistic link between PTEN loss in breast cancer cells, PARP1 activation, and cell survival and tumor growth. Targeting the noncanonical activity of EPRS1, without inhibiting canonical tRNA ligase activity, provides a therapeutic approach potentially supplementing existing PARP1 inhibitors.

Litsea cubeba essential oil: Extraction, chemical composition, antioxidant and antimicrobial properties, and applications in the food industry.

Litsea cubeba (Lour.) Pers. (Lauraceae) is a valuable industrial crop that produces essential oil. The essential oil extracted from L. cubeba (LCEO) has broad-spectrum antimicrobial activity and high antioxidant properties, with great potential for increased usage in the food industry. This literature review summarizes the extraction techniques, content and chemical composition, and antioxidant and antimicrobial activities of LCEO, with a focus on its usage in the food industry, which is an area of substantial recent research. The chemical composition of LCEO, which is affected by various factors, plays a key role in determining its bioactivity and usage in food. The potent antimicrobial activity of LCEO against various foodborne pathogens gives it potential for use in food packaging and preservation to extend shelf life. Future research challenges include the elucidation of the role and mechanism of individual chemical components of LCEO in inhibiting specific foodborne microorganisms; cultivar development to produce germplasm that yields essential oils of the desired chemical composition; and the development of commercial products that can be used in the food industry.

Post-translational activation of the C-terminus of polypeptides for the synthesis of peptide thioesters and peptide thioester surrogates.

Semisynthesis using recombinant polypeptides is a powerful approach for the synthesis of proteins having a variety of modifications. Peptide thioesters, of which the peptide C-terminus is activated by a thioester, are utilized for coupling peptide building blocks. Biological methods employing intein have been a center for the C-terminal thioesterification of recombinant polypeptides. Chemical activation has emerged as an alternative methodology for synthesizing peptide thioesters from recombinant polypeptides. Chemical reactions are compatible with various solutions containing organic solvents, chaotropic reagents, or detergents that are generally incompatible with biomolecules such as intein. Despite the potential utility of chemical activation, available methods remain limited. This article introduces the methods for the chemical activation of a peptide C-terminus applied to the chemical synthesis of proteins. By showcasing these methodologies, we aim to accelerate the advancement of new chemical reactions and methodologies and broaden the frontiers for the chemical synthesis of proteins.

Production of activated carbons from Quercus cerris acorn shell under various experiment conditions, and their characterizations

Due to the high porosities, large surface areas, insolubilities in solutions, and unique structural and morphological structures, porous materials are utilized in various application areas such as energy conversion and storage, wastewater treatment, adsorption, catalysis and photocatalysis. In this study, activated carbons (QCACs), one type of porous materials, were synthesized from Quercus cerris acorn shells by using ZnCl2 chemical activation under various production conditions. The effects of carbonization temperature, carbonization period, and impregnation ratios on the yields, surface areas, pore developments, and N2 adsorption–desorption isotherms of activated carbons obtained were investigated in detail. The highest surface area (1751.61 m2/g) was reached when utilized at the impregnation ratio of 2.0 at 500 ℃ for 90 min. The total pore volume of QCAC increased with increasing impregnation ratio, however the micropore volume of QCAC reduced. It was found from the pore distribution data that QCACs contained mostly narrow mesopores and a little amount of micropores. Also, N2 adsorption–desorption isotherm data revealed that QCACs produced under different conditions were usually mesopore structures, and the pores were narrow slit-shaped. Moreover, the data provided from SEM, FTIR, Boehm titration, and elemental analysis gave more characterization information about QCACs synthesized.

Hydrodynamic cavitation overall intensity evaluation via noise characterization and its effect on phenol oxidative degradation

In the present research, noise signals generated by Hydrodynamic cavitation (HC) are charcterized to provide an applicable direct measuring for overall intensity estimation of the phenomenon. The signals amplitude plots as well as spectrogram graph and Fast Fourier Transform (FFT) are used for the characterization of the noise generated by the cavitation phenomenon for each experiment. In order to validate the outcomes, results are complied with the chemical activity. For such a purpose, phenol oxidative degradation kinetics is selected. Experiments are performed at various HC inlet pressure (4–7 bar), operating temperature (20–40 °C) and concentration of H2O2 (0–1000 mg L−1). It was found that the amplitude mean square of the cavitation noise signals could be introduced as a quantitative index for HC overall intensity. The results imply a direct correlation of HC overall intensity with chemical reaction at constant temperature. According to the results, it can also be also concluded that H2O2 presence can affect the intensity of HC and facilitate the super cavitation occurrence, as well as its expected beneficial effect on phenol degradation. The optimum values of the signal characterization and chemical experiments are in the same wavelength showing an 88.9 % degradation in the presence of 1000 mg L−1 H2O2 at 5 bar inlet pressure.

Tailoring Macro/Meso/Microporous Structures of Cellophane Noodle-Derived Activated Carbon for Electric Double-Layer Capacitors.

To address the bottleneck associated with the slow ion transport kinetics observed in the porosity of activated carbons (ACs), hierarchically structured pore sizes were introduced on ACs used for electric double-layer capacitors (EDLCs) to promote ion transport kinetics under fast-rate charge-discharge conditions. In this study, we synthesized cellophane noodle-derived activated carbon (CNAC) with tailored porous structures, including the pore volume fraction of macro/meso/micropores and the specific surface area. The porous structures were effectively modulated by adjusting the KOH concentration during chemical activation. In addition, optimized KOH activation in CNAC modulated the chemical bonding ratios of C=O, pyrrolic-N, and graphitic-N. Given the hierarchically designed porous structure and chemical bonding states, the CNAC fabricated with optimized KOH activation exhibited a superior ultrafast rate capability in EDLCs (132.0 F/g at 10 A/g).

Study of essential oils and hydroalcoholic extracts obtained from Clinopodium vimineum (Lamiaceae), according to its different phenological stages

ABSTRACT The Caribbean shrub, Clinopodium vimineum, had its essential oil (EO) and hydroalcoholic extracts analyzed across three growth stages: vegetative, flowering, and post-flowering. The chemical composition of the EOs was analyzed by GC/MS/FID and that of the extracts was studied by UHPLC/ESI-Q-Orbitrap-MS. Twenty six compounds (>0.1%) were detected in the EOs of C. vimineum. p-Menth-3-en-8-ol (35–40%) and pulegone (27–30%) were the major components. Among the hydroalcoholic extracts, hydroxycinnamic acids (18–46 mg/g) and glycosylated flavones (17–19 mg/g) were found. The amounts of rosmarinic acid (20–40 mg/g) in the extracts isolated from the hydrodistillation residual biomass were twice as high as those in the extracts from the fresh plant material. The antioxidant activity of the EOs and extracts was evaluated by the ABTS+• and ORAC assays. No significant differences (p > 0.05) were found in the chemical composition or antioxidant activity of EOs and hydroalcoholic extracts, obtained from plants collected at different phenological stages.

Chemical Characterization and Biological Activities Evaluation of Myrtus communis L. Essential Oil Extraction By-Product towards Circular Economy and Sustainability.

Essential oil (EO) extraction is a widespread practice generating huge amounts of solid plant by-products a potential source of bioactive compounds, on the one hand, and a detrimental risk for the environment that needs to be carefully considered on the other hand. The present study aims to valorize Myrtus communis L. leaf by-products obtained following EO extraction using a steam distillation unit through the recovery of phenolic compounds and the evaluation of their biological activities. The total phenols, flavonoids, and proanthocyanidins contents of the ethanolic extract by-product were higher than the control (leaves without extraction of EO). Their amounts increased from 69.30 to 88.06 mg GAE/g for total phenols, from 36.31 to 70.97 mg QE for flavonoids and from 19.74 to 21.49 mg CE/g of extract for proanthocyanidins. The identification of phenolic compounds by high-performance liquid-chromatography equipped with a reversed-phase (RP-HPLC) system revealed that the by-product sample includes more gallic acid, catechin, syringic acid and luteolin 7-O-glucoside but less p-coumaric acid and kaempferol than the control. Moreover, the mid-infrared spectroscopy (MIR) showed the presence of benzene ring characteristic of phenolic compounds at 756 cm-1, esters of aromatic acids and stretching vibrations of polyphenols at 1141-1234 cm-1, C=C stretching present in phenolic acids such as coumaric acid and catechin at 1604 cm-1. The assessment of antioxidant activity revealed that the ABTS+• radical scavenging activity was significantly increased, whereas the DPPH• radical inhibition activity and the ferric reduction antioxidant power were significantly decreased. The results indicated, as well, that Myrtus communis L. leaf by-products maintained a considerable antibacterial activity depending on the tested bacterial strain. Additionally, the anti-α-amylase activity was higher for the Myrtus communis L. leaf by-product extract. Therefore, Myrtus communis L. leaf by-products of EO extraction offer phenolic compounds with significant biological activities, contributing to the sustainable development and the promotion of circular economy by the recovery of valuable inputs from plant by-products.

Efficient Demulsification of Crude Oil Emulsion Using Novel Sugar-based Surfactant.

This study aimed to synthesize ecofriendly and low-cost surfactant-based sugar, HA-ST, under mild conditions and a short route via an opening ring of hexadecylsuccinic anhydride (HA) using starch (ST). HA-ST's chemical structure, thermal behavior, and surface activity were evaluated using Fourier Transform Infrared (FTIR) spectroscopy, thermogravimetric analysis, and a pendant drop technique. The results indicated HA-ST formation, thermal stability, and surface activity. HA-ST's green character, low cost, and surface activity recommended its use as a demulsifier for crude oil emulsions at different affecting parameters such as temperature, seawater ratio (SR), demulsifier concentration, demulsification time (DT), and pH. HA-ST demulsification efficiency (DE) was evaluated and compared with a commercial demulsifier (CD). The results showed improved HA-ST's DE with rising temperature, SR, demulsifier concentration, DT, and pH. The DE of HAST reached 100% at 50% of SR and 250 ppm of demulsifier concentration; the same results were obtained using CD. In contrast, HA-ST gave relatively lower DE at low SR (10%) with a value of 70% than the obtained using CD with a value of 75%. The green character, low cost, and DE of HA-ST make it suitable for demulsifying crude oil emulsions, especially those containing more than 30% seawater, compared with CD, which commonly contains two or more traditional surfactants.

Ultrasound‐assisted synthesis of biodiesel in the presence of a novel catalyst recovered from waste effluent/water: A mini‐review

AbstractThe government of India has mainly focused on waste management, environment protection acts, and control of energy demand, which will lead to the development of a clean and green India. Nowadays most of the drinking water is getting polluted due to the harmful gases released by well‐renowned industries mining operations, alloy industries, and dye industries. The presence of more amounts of heavy metals in drinking water leads to a rise in chemical levels than the constrained level in the environment, inside a human body, and any living being. Protection of the environment through the recovery of heavy metals from waste effluents through a chemical activation process using bio‐derived activated carbons as adsorbents is one of the known strategies in the current decade that can be adopted. The application of these heavy metals as catalysts in the synthesis of biodiesel from nonedible oils through an ultrasound (US)‐assisted process is one of the emerging strategies that will help in the reduction of energy demand. In the current review, the recovery of heavy metals from the waste effluents through a conventional chemical activation process and their applications as catalysts in the US‐assisted synthesis of biodiesel from nonedible oils is discussed.

Transforming a mixture of real post-consumer plastic waste into activated carbon for biogas upgrading

Plastic waste management is a current environmental issue that demands potential solutions since complete mechanical recycling is limited to the complexity and feasibility regarding the quality and purity of plastic waste. Pyrolysis has emerged as a reasonable solution for the recycling of those fractions that are not further suitable for recycling. Although the implementation of this technology is mature, the generated solid fraction or char has not been completely inserted in the closed loop of plastic recycling. This work explores the possibility of using the carbonaceous char as a precursor for the preparation of porous activated carbons for environmental application as CO2 adsorbent and biogas upgrading. The effect of the pyrolysis temperature (450 or 500 ºC) on the obtained chars has been assessed for the benefits in the second stage of chemical activation, exploring the possibility of the use of diverse chemical agents. The composition, textural, and surface properties of the porous materials were characterized. N2 isotherms showed that the char prepared at 500 ºC provided the best textural properties with a performance of K2CO3 ∼ KOH > Na2CO3 > NaOH > ZnCl2 > FeCl3. Isotherms of CO2 adsorption showed that the activation with K2CO3 displayed the best uptake (130.2 mg g−1 at 273 K), closely followed by KOH (125.0 mg g−1 at 273 K), also confirmed by dynamic tests in a fixed bed column configuration. The uptake was well correlated with the ultramicropore volume and the oxygenated functional groups. The CO2 and CH4 adsorption were studied either in static or dynamic assays. The behavior of the sample activated with K2CO3 was studied in detail in column tests, suggesting that the activated material exhibits promising behavior for biogas upgrading.

Green adsorption of quinoline as basic N-compounds from liquid fuel using mesoporous and Fe-functionalized walnut shell-activated carbon

Removing nitrogenous compounds from liquid fuels is essential, and adsorption de-nitrogenation is a new process for this goal. This work has the purpose of investigating quinoline adsorption using Iron functionalized Activated carbon (IFAC) mesoporous nanocomposite. The mesoporous nanocomposite was synthesized in a one-step process by chemical activation of the walnut shell using Iron chloride as the activation and modification agent. The IFAC mesoporous nanocomposite was utilized to remove quinoline from isooctane as the liquid fuel via a discontinuous (batch) process by examining the effect of initial concentration, contact time, and temperature. The effect of contact time on the adsorption ability of IFAC for quinoline was well described by the pseudo-second-order model. The Langmuir model described the equilibrium manner of the process well, and the adsorbent could retain 344.82 mg/g of quinoline (37.37 mg N/g). The thermodynamic parameters show the endothermic (ΔH°= +30.070 kJ/mol) and spontaneity of the adsorption process. The regeneration experiments indicated that functionalized AC’s adsorption ability for quinoline adsorption decreased by 23% after five cycles. The obtained data indicate that the functionalization of activated carbon surface with iron particles leads to improving its adsorption ability toward N-containing compounds from liquid fuels.

Optimization of Hydrochemical Leaching Process of Kaolinite Fraction of Bauxite with Response Surface Methodology

A technology for the hydrochemical processing of the kaolinite fraction of bauxite has been developed, and it involves preliminary chemical activation in a sodium bicarbonate solution and alkaline leaching in a recycled high-modulus solution with the addition of an active form of calcium oxide. Chemical activation allows for the transformation of the difficult-to-explore kaolinite phase to form easily soluble phases of dawsonite, sodium hydroaluminosilicate and bemite. An active, finely dispersed form of calcium oxide was obtained as a result of CaO quenching in Na2SO4 solution at elevated temperature and pressure. Using a central composite design (CCD) via response surface methodology (RSM), the technological leaching mode was achieved. The influence on the leaching process was studied by adjusting the CaO/SiO2 ratio, temperature, alkaline solution concentration and duration. It was found that the determining factors are the concentration of the leaching solution and the temperature. At a stable CaO/SiO2 ratio, a combination of these two factors determines the duration of the process to achieve the predicted degree of recovery. The results of experiments carried out using the developed model of the leaching process confirmed the validity of the calculated indicators, with an error of 2.01%. In an optimal technological mode at a Na2O leaching solution concentration of 260 g/L, a temperature of 260 °C, a CaO/SiO2 ratio of 1.5 and a leaching time of 5 h, the extraction of Al2O3 into the solution was 89.7%, which is close to the value of 87.9% predicted by the model.

Valorization of argan paste cake waste: Enhanced CO2 adsorption on chemically activated carbon

This study addresses the critical need to reduce energy penalties in CO2 capture processes by exploring the potential of activated carbons derived from argan paste cake for post-combustion CO2 capture applications. Leveraging their cost-effectiveness, stability in humid conditions, and microporous structure, a series of activated carbons with diverse textural characteristics were synthesized through a two-step chemical activation process employing a KOH: biochar ratio of 1:1. Activation temperatures ranged from 700 to 850 °C. Characterization techniques such as Raman spectroscopy, X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, elemental analysis, and Fourier-transform infrared spectroscopy were employed to analyze the structural and chemical properties of the synthesized activated carbons. Remarkably, all synthesized samples exhibited excellent CO2 adsorption properties. Notably, the activated carbon sample prepared at 700 °C (APC-500–700) demonstrated the highest CO2 adsorption capacity, reaching up to 4.89 mmol/g at 0 °C and 2.98 mmol/g at 25 °C. Additional samples, including APC-500–800 and APC-500–850, exhibited CO2 adsorption capacities of 4.89 mmol/g and 4.83 mmol/g, respectively, at 0 °C, with corresponding values of 2.74 mmol/g and 2.60 mmol/g observed at 25 °C. Selectivity and stability tests were conducted to evaluate the adsorption performance under varied conditions, further highlighting the potential of activated carbon derived from argan paste cake in contributing to efficient CO2 capture processes. These findings underscore the significance of synthesis conditions in tailoring adsorption performance and pave the way for the sustainable utilization of waste biomass for environmental applications.

Development of a novel Al-Si microcapsules with heat-resistant, high latent heat, and efficient solar heat absorption

Aluminum-silicon (Al-Si) alloys are prominent in high-temperature thermal storage due to their high thermal storage density, thermal conductivity, and low cost. Despite their potential, the corrosivity and chemical activity from their liquid phase leakage limit broader applications. The hydrothermal method, often used for encapsulating Al-Si into microencapsulated phase change materials (MEPCMs), consumes the core material, reducing latent heat values. Additionally, the inability to modify the shell material fails to meet multifunctional demands. Addressing solar thermal application needs, we developed a novel heat-resistant, high-latent-heat Al-Si MEPCMs using a “double-layer coating, sacrificial inner layer” approach. This method, originally proposed by our research group and first extended to the microencapsulation of high-temperature phase change materials (PCM), uses Al-12Si as the core, PMMA as the sacrificial layer, and SiO2 as the outer shell.The MEPCMs demonstrated an encapsulation efficiency of 90.7 % and a latent heat value of 454.9 J/g. By adjusting the core–shell ratio, the size of the internal void was optimized to enhance thermal performance and cyclic stability, with MEPCM-S3 maintaining 98.6 % of its latent heat (439.5 J/g) after 10 thermal shocks and 300 thermal cycles. Furthermore, surface loading of carbon black (CB) enhanced the spectral absorption rate to 87.72 % in the 200–2500 nm range, marking an 11 % increase. These modifiable, high-latent heat, and cycle-resistant Al-Si MEPCMs hold broad prospects for applications in high-temperature thermal storage and as next-generation efficient solar energy storage media.

Exploring chemical composition and insecticidal activities of Alpinia calcarata rhizome essential oil against three major storage insects

Alpinia calcarata (Roscoe), generally recognized as snap ginger or lesser galangal of the Zingiberaceae family, undergoes widespread cultivation in tropical nations. It is characterized by its noteworthy pharmacological attributes, such as anti-inflammatory, analgesic, antinociceptive, reproductive, anti-cancer, and gastro-protective effects. Many storage pests now resist traditional chemical pesticides. Transitioning to organic alternatives is a preferable and sustainable solution. This research investigates the insecticidal activity of essential oil from A. calcarata rhizomes, obtained via hydro-distillation. Chemical analysis was conducted, and the study assessed its toxicity and repellent effects on Tribolium castaneum (Herbst), Lasioderma serricorne (F.), and Callosobruchus chinensis (L). A yield of 0.44 ± 0.02 % essential oil was obtained from dry rhizomes. Gas chromatography-mass spectrometry (GC-MS) characterization revealed the major chemical constituents as 1,8-cineole (25.71 %), ethyl iso-allocholate (16.01 %), and fenchyl acetate (15.15 %). The findings from the investigation into the pesticidal characteristics of essential oils derived from the rhizome of A. calcarata unveiled significant contact (LC50 at 24 h was 10.9 mg/cm2 for T. castaneum, 1.0 mg/cm2 for L. serricorne and 0.5 mg/cm2 for C. chinensis) and fumigant toxicity (LC50 at 24 h was 4.05 mg/L air for T. castaneum, 1.75 mg/L air for L. serricorne, and 1.03 mg/L air for C. chinensis). The repellent efficacy was evaluated through an area preference test, revealing robust repellent activity at various concentrations. Undoubtedly, the essential oil extracted from the rhizome of A. calcarata is valuable and has the potential to be a safe, organic pesticide for controlling storage pests.