Chemical Activation Research Articles

Application of sewage sludge derived hydrochar as an adsorbent for removal of methylene blue

Hydrothermal pretreatment (HTP) is used to convert biomass into hydrochar (HC) through the application of heat and pressure in a water-based medium. The HC has emerged as a promising material for various environmental applications including wastewater treatment, soil amendment, and carbon sequestration. In this study, the applicability of sewage sludge (SS) derived HC was tested as an adsorbent for methylene blue (MB) dye removal from wastewater. The HC was also subjected to chemical activation with KOH before the adsorption study. The HC samples were characterized for structural morphology and molecular functionalities using instrumental analysis. All the HC samples exhibited almost similar adsorption capacity (∼190 mg/g) for MB after 24 h of contact time (MB concentration = 200 mg/L, solution pH = 7 and adsorbent dose = 1 g/L). The equilibrium data could be adequately fit in Langmuir model equation. The negative value of free energy indicated favorable MB adsorption process. The study demonstrated that the SS derived HC can be recycled as adsorbent in wastewater treatment plant which is not only an environment-friendly approach but also may reduce cost of tertiary treatment at sewage treatment plant often required to remove emerging contaminants.

A New Process of Chemical Plating Ni-P Electromagnetic Induction Heating Activation on the Surface of Aluminium Alloy Base Material

Nowadays, there are many surface treatment methods for aluminium alloys; the most commonly used of these is the chemical dip galvanizing process, which is complicated due to its use of large quantities of corrosive drugs. In order to simplify the process, this paper proposes a new electromagnetic induction heating activation method instead of the zinc dipping process. The method works as follows: The substrate is first degreased and then activated. The activation process starts by soaking the degreased substrate in an activation solution, taking it out after ten minutes, and placing it into an induction heating unit. The activation solution is sprayed onto the surface of the substrate while heating, using the energy generated by high temperatures to complete the activation reaction. The surface of the activated substrate forms a nanoscale film of nickel, which is finally utilised as a catalytic centre for ENP (an advanced surface treatment process that deposits a very uniform layer). The optimisation of important parameters of the non-destructive activation process was determined using the L9 Taguchi method. The main parameters ranged from 0.15 L/min to 0.25 L/min for spray rate, 200 °C to 400 °C for heat treatment temperature, and 1:4, 1:5, and 1:6 for Ni2+ and H2PO4− ion concentration ratios. The above data were derived from a single variable and were analysed using Minitab 20 software. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy spectrometry (EDS), and ultrasonic experiments were used to characterize and analyse the surface morphology, composition, and bond strength of the coatings. The results show that the nanoscale nickel particles can completely cover the surface of the substrate, forming a layer of nano-film. After activation and ultrasonic cleaning for 30 s at an ultrasonic frequency of 40 KHz and a power of 80 W, the surface nano-film was not destroyed, which proves that it had a high bonding strength. After the application of the plating, the plated surface had a compact microstructure, and the continuity was good. Therefore, compared with the currently commonly used zinc dipping process, this process has the advantages of being a low-cost, simple operation, and non-destructive and environmentally friendly activation process for the substrate.

Excipient effects on supersaturation, particle size dynamics, and thermodynamic activity of multidrug amorphous formulations

Multidrug formulations enhance patient compliance and extend the life cycle of pharmaceutical products. To overcome solubility challenges for multidrug combinations, amorphous formulations are commonly used. However, the excipients for creating amorphous formulations are often selected without an understanding of their effects on the bioavailability of the drugs. In this context, we investigated the impact of three types of excipients (polymers, surfactants and amino acids) on the supersaturation and thermodynamic activity of multidrug amorphous formulations. Additionally, we studied the particle size dynamics of the colloidal phase formed as a result of liquid–liquid phase separation. The amorphous solubility of two drugs, atazanavir and ritonavir, was determined in solutions containing predissolved excipients and the particle size dynamics of the colloidal particles was measured by dynamic light scattering. Dissolution experiments of atazanavir and ritonavir were conducted in predissolved sodium dodecyl sulfate (SDS), an anionic surfactant, and alanine solutions under non-sink conditions. Membrane transport of the drugs was evaluated using a MicroFLUX setup. The polymers had only minor effects on the amorphous solubility, but SDS significantly increased the solubilities of both drugs. In contrast, the other non-ionic surfactants and amino acids reduced the solubility of atazanavir but had no negative effect on ritonavir. Polymers were effective in maintaining supersaturation and preventing the coarsening of the colloidal particles. Conversely, alanine was neither able to inhibit the solution crystallization nor increase the flux of either drug. Despite the increase in the amorphous solubility of both drugs in SDS, flux was reduced. These results highlight the importance of properly selecting excipients for supersaturating amorphous formulations. The choice of excipient impacts the thermodynamic activity, the phase behaviour of the drugs and hence, the resulting absorption after oral intake.

Comparative Analysis of Chemical Profiles and Biological Activities of Essential Oils Derived from Torreya grandis Arils and Leaves: In Vitro and In Silico Studies.

Torreya grandis (T. grandis, Taxaceae) is a well-known nut tree species. Its fruit aril and leaves possess a unique aroma, making it an ideal natural raw material for extracting essential oils (EOs). This study aims to comprehensively compare the composition, biological activities, and pharmacological mechanism of EOs extracted from the arils (AEO) and leaves (LEO) of T. grandis. The results revealed that the chemical composition of the two EOs was highly consistent, with α-pinene and D-limonene as the main components. Both EOs significantly reduced cellular melanin production and inhibited tyrosinase activity in α-MSH-stimulated B16 cells (p < 0.05). AEO and LEO suppressed inflammatory responses in LPS-stimulated RAW 264.7 macrophages, significantly inhibiting cellular NO production and proinflammatory cytokines such as TNF-α and IL-6 (p < 0.05). A network pharmacology analysis reveals that AEO and LEO share similar molecular mechanisms and pharmacological pathways for treating skin pigmentation and inflammation. Regulating inflammatory cytokines may be a critical pathway for AEO and LEO in treating skin pigmentation. These findings suggest that AEO and LEO have potential for cosmetic applications. The leaves of T. grandis could be a valuable source of supplementary materials for producing T. grandis aril EO.

Qualitative Profiling, Antioxidant and Antimicrobial Activities of Polar and Nonpolar Basil Extracts.

Basil (Ocimum basilicum L.) is a widely used culinary herb. In this study, ethanol, dichloromethane, and sunflower oil were used separately as solvents with distinct polarities for the extraction of basil aerial parts to simulate the different polarity conditions in domestic food processing. The oil extract (OE) was re-extracted with acetonitrile, and the chemical composition, antioxidant potential, and antimicrobial activities of the ethanol (EE), dichloromethane (DCME), and acetonitrile (ACNE) extracts were determined. A total of 109 compounds were tentatively identified in EE, DCME, and ACNE by HPLC-DAD/ESI-ToF-MS. Fatty acids were present in all extracts. Phenolic acids and flavonoids dominated in EE. DCME was characterised by triterpenoid acids, while diterpenoids were mainly found in ACNE. The extracts were analysed for their antioxidant capacity using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. EE and DCME showed significant radical scavenging potential. Antimicrobial activity was explored in eight bacterial, two yeast, and one fungal species. All extracts exhibited high antifungal activity, comparable to or better than that of the commercial drug nistatin. Antibacterial activities were notable for EE and ACNE, while DCME showed no activity against bacteria in the applied concentration ranges. The different polarities of the solvents led to distinctive phytochemical compositions and bioactivities in the extracts.

Activated biomass-derived 3-dimensional porous graphene-like carbon for high-performance energy storage electrode materials

This article reports studies on the fabrication of active material for supercapacitor electrodes, from 3D porous graphene-like carbon (GLC), synthesized by carbonization from coffee waste (CW) and tea waste (TW) at 550 °C, followed by thermochemical activation in KOH at 850 °C in a quartz tubular furnace. The microstructure of coffee and tea waste shows the form of micro- and mesopores during carbonization and further chemical activation forms hierarchically highly porous 3D graphene-like carbon. GLC-CW exhibited a higher specific surface area (SSA) of 3486 m2/g according to the Brunauer-Emmett-Teller (BET) method, compared to GLC-TW, which had an SSA of 2407 m2/g. These results highlight the effectiveness of graphene-like carbon derived from coffee and tea waste, demonstrating its potential as a promising material for high-capacity supercapacitors. The electrochemical characteristics of the assembled supercapacitors using GLC-CW and GLC-TW revealed significantly higher specific capacitance values of 214 F/g and 182 F/g respectively, along with cycling stability of 98 % and 95 % during 5000 cycles of charge and discharge at 2 A/g current density. This approach can produce high-performance electrode materials for supercapacitors at a reasonable cost and with easy scalability.

Antioxidant and Biological Activity of Mexican Madroño Fruit (Arbutus arizonica).

The fruit of the Mexican madroño (Arbutus arizonica) has been consumed since pre-Columbian times by North American tribes and native groups in Mexico. Despite this, reports on its chemical composition and biological activity are limited. This work aims to determine the antioxidant, antiproliferative, and digestive enzyme inhibition activities of the methanol amberlite-retained extract of Mexican madroño. Results showed that madroño fruit is rich in antioxidants: DPPH (EC50 = 0.89 ± 0.03 mg/mL), TEAC (1078 ± 4.9 μM/g), and hemolysis inhibition (IC50 = 358.07 μg/mL), with high phenolic and flavonoid content at 15.92 ± 3.2 mg GAE/g and 4.33 ± 0.3 mg CA/g, respectively. Using analytical chromatography, gallic acid, vanillic acid, chlorogenic acid, ferulic acid, quercetin, and rutin were quantified. The extract also showed α-glucosidase inhibition (IC50 = 3.1 ± 0.17 mg/mL), but no inhibition against α-amylase and lipase (>5 mg/mL), while showing antiproliferative activity against HeLa, HT-29, and MCF-7 cancer cell lines. These results point towards an interesting potential for the fruit of the A. arizonica as chemopreventive and hold potential for elaborating functional foods.

Chemical Activation of S/Li2S in Li-S Batteries by a Bidirectional Organic Redox Mediator

Chemical Activation of S/Li2S in Li-S Batteries by a Bidirectional Organic Redox Mediator

Preparation and characterization of activated carbon from medlar seed by chemical activation with phosphoric acid and its application in uranium adsorption

Preparation and characterization of activated carbon from medlar seed by chemical activation with phosphoric acid and its application in uranium adsorption

Insights into the Chemical Structure and Antioxidant Activity of Lignin Extracted from Bamboo by Acidic Deep Eutectic Solvents.

Deep eutectic solvents (DESs) composed of choline chloride as hydrogen bond acceptors (HBAs) and six organic acids as hydrogen bond donors (HBDs) were used to extract lignin from bamboo (Phyllostachys edulis (Carrière) J. Houz.). The structures of the DES-extracted lignin samples were analyzed by Fourier-transform infrared spectroscopy (FT-IR), UV-visible spectroscopy (UV-vis), thermogravimetric analysis (TG), and gel permeation chromatography (GPC) to investigate the relationship between the chemical structure of lignin and its antioxidant activity. The results showed that DES treatment removed a large portion of the lignin (73.37-86.38%) from bamboo, and the chemical structure of lignin was changed due to the use of different types of HBDs. The extracted lignin exhibited good UV-vis light shielding properties, thermal stability, and antioxidant activity. Moreover, the total phenolic hydroxyl content of lignins was positively correlated with their antioxidant activity, while the molecular weight of lignins was negatively correlated with their antioxidant activity. Notably, lignin extracted with choline chloride-p-toluenesulfonic acid had the highest phenolic hydroxyl content and lower molecular weight, showing the strongest antioxidant activity (IC50DPPH = 417.69 μg/mL, IC50ABTS = 58.62 μg/mL). This study confirms the high thermal stability, excellent antioxidant activity, and UV shielding properties of lignin extracted with choline chloride-organic acid DESs, suggesting its potential application in the fields of antioxidants and material modifiers.

Study on the anti-HBV activity of matrine alkaloids from Oxytropis ochrocephala by MTT, 3d-QSAR, molecular docking and molecular dynamics simulation

To elucidate the structure-activity relationship of 17 matrine alkaloids from Oxytropis ochrocephala Bunge, their effect on hepatitis B surface antigen (HBsAg) secretion was studied using the MTT assay. A 3D-QSAR analysis showed a strong correlation between chemical structures and biological activities (q2 = 0.625, r2 = 0.859). Molecular docking and molecular dynamics simulations revealed that hydrogen bonding and hydrophobic interactions with hepatitis B core protein (PDB:5T2P) are key to inhibiting HBsAg secretion, suggesting potential for developing natural anti-hepatitis B drugs.

In vitro and in silico therapeutic properties of Artepillin C and Aromadendrin as collagenase and elastase inhibitors and investigation of anti-Ovarian cancer effects and antioxidant potential

In this investigation, the enzymes collagenase and elastase were inhibited by artepillin.C and aromadendrin molecules with excellent to good IC50 values of 16.65, and 0.79 μM for artepillin.C and 7.31, 19.38, and 10.56 μM for aromadendrin. Using the molecular modeling study, the chemical activity of these compounds against the enzymes, collagenase, and elastase were evaluated. The anti-cancer properties of the compounds were evaluated using the following cell lines: NIH: OVCAR-3, ES-2, UACC-1598, Hs 832(C).T [Hs832.Tc], TOV-21G, UWB1.289. The DPPH (1,1-diphenyl-2-pricrylhydrazyl) free radical scavenging assay was used to measure antioxidant activity, and the spectrophotometric method was used in this work. The chemical activities of artepillin.C and aromadendrin against collagenase and elastase were investigated utilizing the molecular docking study. The anti-cancer activities of the compounds were evaluated against NIH: OVCAR-3, ES-2, UACC-1598, Hs 832(C).T [Hs832.Tc], TOV-21G, UWB1.289 cell lines. Also, some cell lines had best results for aromadendrin like NIH: OVCAR-3, ES-2, UACC-1598, Hs 832(C).T [Hs832.Tc], TOV-21G, UWB1.289 (10.54 ± 0.94, 22.11 ± 2.52, 31.85 ± 4.73, 8.14 ± 1.52, 17.94 ± 1.88, and 24.31 ± 2.64 μM). The chemical activities of artepillin.C and aromadendrin against some of the expressed surface receptor proteins (folate receptor, CD44, EGFR, Formyl Peptide Receptor–Like 1, M2 muscarinic receptor, and estrogen receptors) in the mentioned cell lines were assessed using the molecular docking calculations. The outcomes provided information on potential interactions and their atomic-level properties. According to the docking scores, the compounds show a high affinity for binding to proteins and enzymes. Furthermore, these substances made good contact with the receptors and enzymes. As a result, these substances may have the ability to suppress cancer cells and enzymes.

Targeted construction of porous biochar with well-developed pore structure for high-performance CO2 adsorption

Targeted construction of porous biochar is vital for the development of carbon capture. In this paper, we use the KOH chemical activation with walnut shell as raw material, to investigate the effects of the preparation process on the targeted construction of CO2 adsorbents. We have revealed the vital factors influencing CO2 adsorption and developed the design strategy for porous biochar under different application conditions. The specific surface area can up to 2115 m2 g−1, and the microporosity can up to 95.5 %. The CO2 adsorption capacities are 6.75 mmol g−1 and 17.59 mmol g−1 at 0°C, 1 bar and 10 bar. Meanwhile, the heat of adsorption ranges from 18 to 30 kJ mol−1. In addition, the sample exhibits outstanding adsorption kinetics, good adsorption selectivity, and its CO2 adsorption capacity fluctuates within 5 % after 10 adsorption-desorption cycles. Therefore, the strategy developed in this paper can be applied to the high-performance adsorption of CO2 under different conditions.

Entropy formation in second grade nanofluid flow across a curved surface with the impact of activation energy and chemical reaction

The heat and mass transfer through the second-grade nanofluid across a curved surface is investigated in the present article with the consequences of chemical reaction, activation energy and Ohmic heating. The Buongiorno model is employed to simulate the thermophoretic and Brownian diffusions effect. The flow phenomena for second-grade fluid (SGF) have been modelled in the form of system of partial differential equations (PDEs) which are converted into a system of ordinary differential equations (ODEs) by substituting the similarity variables. The model equations are converted into a system of ODEs by inserting a suitable variable. The set of dimensionless equations along with boundary conditions are evaluated computationally through the numerical differential equation solver (ND Solve) technique. The entropy optimization, energy curve, Nusselt number, mass transfer, Sherwood number, velocity and skin friction are computed and examined versus distinct physical parameters. The finding reveals that the concentration and velocity profile exhibits enhancement as the curvature parameter increases, whereas an opposite trend has been found in relation to the energy outline. Furthermore, the concentration profile raises as the activation energy increased, while diminishes with the augmentation of chemical reaction.

Chemical Composition and Biological Activities of Essential Oil from Oreocallis grandiflora

Chemical Composition and Biological Activities of Essential Oil from Oreocallis grandiflora

Total Chemical Components, Biological Activity and Chromatographic Analyzes of Styrax officinalis Fruit Extract

This study aims to investigate the total chemical component, biological activity and chromatographic analysis of the fruit extract of Styrax officinalis, obtained from local markets trading local products in the Gaziantep region. Methanol was used to extract the pericarp and seed samples that make up the fruit. Fruit pericarp extract with high phenolic content showed a significant capacity in all antioxidant activity analyses. No antibacterial activity of the extracts was observed against the standard strains used. Regarding phenolic acid content, the most abundant phenolic acid in the fruit pericarp extract was chrysin and t-cinnamic acid. In contrast, in the seed extract, it was t-cinnamic acid and quercetin. HPLC results revealed that succinic acid was the main component of organic acid contents in all extracts. The fact that the main components determined from all analyses have various strong pharmacological activities reveals the importance of the widespread use of S. officinalis.

Investigation on a sustainable magnesium phosphate cement (MPC) with recycled waste MPC powders

Magnesium phosphate cement (MPC) has been used for the structure rapid-repair of damaged buildings. To reduce the cost and resource consumption during MPC preparation, recycled MPC powders were used to prepare an environmental-friendly MPC by replacing the dead burned MgO powders. The workability and early hydration temperature development of MPC paste with recycled powders were investigated. To characterize the effect of recycled powders on the performance of the MPC paste, the mechanical properties, volume stability, phase developments and microstructures were determined. The results showed that due to the small particle size and the large specific surface area, the recycled powders absorbed part of the water during the mixing and reduced the fluidity of the MPC paste. The chemical reaction activity of recycled powders was lower than that of MgO powders, resulting in the reduction of the hydration reaction rate and hydration products of MPC. With the recycled powder content increasing, the mechanical strength and volume stability of MPC decreased. The decreased strengths could be attributed to the poor MPC paste structure with increased pores and microcrack content caused by recycled powders. Nevertheless, when the recycled powder content was 40 %, MPC paste obtained a workability of 20.8 cm, setting time of 24.75 min, 3-h compressive strength of 30.9 and 28-d compressive strength of 50.3 MPa. Therefore, under this replacement rate, the MPC paste still had acceptable properties, which could still meet the rapid-repair requirements.

Enhancing the oxygen evolution reaction activity and stability of high-valent CoOOH by switching the catalytic pathway through doping low-valent Cu

The oxygen evolution reaction (OER) is a critical process in electrochemical energy storage and conversion systems. The adsorbate evolution mechanism (AEM) pathway possesses the characteristics of high stability but slow catalytic kinetics. We propose that combining AEM with the lattice oxidation mechanism (LOM) pathway can potentially enhance the OER catalytic activity and stability. However, the triggering of LOM is an important challenge due to the high thermodynamic activation barrier of lattice oxygen. To solve this problem, we performed theoretical calculations and experiments which suggest that the introduction of low-valent Cu in CoOOH (CuxCo1−xOOH) could directionally modulate the local coordination environment of CoO bonds. This approach can activate lattice oxygen and generate oxygen vacancies to enhance the nucleophilic attack of *OH and directly establish OO coupling, thereby facilitating the smoothly switching from AEM to LOM pathway by increasing voltage and thus activating lattice oxygen in CuxCo1−xOOH. The switching of AEM and LOM enables CuxCo1−xOOH showing an outstanding overpotential of only 252 mV (10 mA cm−2) and durability of only 2.80 % degradation after 280h. This work provides a new way for designing efficient and stable electrocatalysts with AEM and LOM pathway switching.

Conductive Li2S‐NbSe2 Cathode Material Capable of Bidirectional Self‐Activation for High‐Performance All‐Solid‐State Lithium Metal Batteries

AbstractAll‐solid‐state lithium metal batteries (ASSLBs) offer an alternative route to safe and high energy density power sources. Sulfur‐based cathodes with high theoretical specific capacity and low cost are crucial for advancing ASSLBs. However, the electronic insulation and sluggish kinetics of sulfide materials like Li2S severely limit battery performance. Herein, the strategy is proposed that a highly electronic conductive Li2S‐NbSe2 material enhances the electrochemical performance through bidirectional self‐activation. The chemical interaction between Li2S and NbSe2 induces NbSe2‐xSx and Li2Se derivatization, serving as the basis for activation. The carrier transport properties, chemical evolution and self‐activation mechanism of Li2S‐NbSe2 during the oxidation–reduction process are revealed. The chemical activation of NbSe2‐xSx is explored to accelerate the electrochemical processes by modifying the conductivity of sulfur species and the conversion pathways without insulating Li2S and S aggregation. Therefore, ASSLBs using Li2S‐NbSe2 as cathode active material achieve an electrode‐level energy density of 394 Wh kg−1 and a power density of 524 W kg−1 at 1 C (4.35 mA cm−2) and 25 °C. The capacity retention after 100 cycles at 0.5 C is ≈99.3% with almost no degradation. This work provides new options and insights for the rational design and development of chalcogenide cathode active materials for high‐performance ASSLBs.

Electric field induced dissociation of a confined hydrogen molecule

The effect of a static electric field ionization on the neutral hydrogen molecule H2 confined in a spherical potential well is studied, as a simple model for the chemical activation of molecular species in a medium. Quantum diffusion Monte Carlo is employed with complete account of electron correlation. Field-induced ionization and dissociation are discussed, for different values of the confinement radius and electric field strength. This study allows to highlight the mechanism of electric field initiation of chemical reactions in fluids at different pressures, without the details of a specific chemical environment.