RSC Advances最新文献

The search for sustainable, cost-effective and environmentally friendly corrosion inhibitors for hydrochloric acid (HCl) solution in industrial applications has garnered increasing interest in plant extracts and their refined metabolites. In this research, Cleome arabica L. (CA) extract, found in the Algerian Sahara, was considered due to its low cost compared to other studied plants and higher content of active compounds, thereby emerging as a promising candidate and offering the potential to promote a circular economy model. This study assessed the effectiveness of CA extract as a green corrosion inhibitor for AISI 1045 carbon steel in 0.5 M HCl solution and highlighted its potential to advance the field of green corrosion inhibitors. ATR-FTIR and LC-ESI-MS/MS analyses revealed the presence of significant organic compounds, including coumaric acid (74.58%), 4-methoxybenzoic acid (12.53%), and kaempferol (8.05%), which contributed to the corrosion inhibition. The inhibitory effectiveness of the CA extract was evaluated at five concentrations, ranging from 0.125 to 1 g L⁻¹, using weight loss measurements, potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The highest inhibition efficiency (η = 94.45%) was observed at a CA extract concentration of 1 g L⁻¹ after 196 hours of immersion in 0.5 M HCl. Thermodynamic analysis using the Langmuir adsorption isotherm yielded a ΔG_ads value of −24.737 kJ mol⁻¹, indicating the spontaneous adsorption of CA molecules onto the AISI 1045 surfaces, forming a protective layer, which was confirmed by SEM/EDX analysis. Density functional theory (DFT) calculations showed a significant correlation with the experimental data, confirming that CA extract is a highly efficient and environmentally friendly corrosion inhibitor.

Two pure fungal strains were isolated and identified from Ficus sycomorus and Morus nigra, namely, Penicillium oxalicum (OR673586) and Phoma herbarum (OR673589), respectively. The extract and fractions of secondary metabolites of each fungus were evaluated for antioxidant, anti-inflammatory, antimicrobial, antibiofilm, antidiabetic, and cytotoxic activities. The chloroform fraction of P. oxalicum showed potent cytotoxic activity (IC₅₀ = 7.695 μg mL⁻¹) against Hep-G2 cell line, alongside moderate antioxidant and anti-inflammatory activities. On the other hand, the P. herbarum chloroform fraction showed potent antioxidant (DPPH IC₅₀ = 5.649 μg mL⁻¹) and antidiabetic activities (IC₅₀ = 14.91 μg mL⁻¹) against inhibition of α-glucosidase, in addition to moderate cytotoxicity, anti-inflammatory, and antimicrobial activities. Guided cytotoxic fractionation leads to identifying bioactive compounds using hyphenated techniques. LC-MS identified fourteen compounds for P. herbarum and thirteen compounds for P. oxalicum. Three known compounds, mevalolactone (1), glycerol monolinoleate (3), and ergosterol (7) in addition to one new compound, barcelonyl acetate (2), were isolated from P. herbarum. On the other hand, four known compounds, 4-hydroxyphenyl acetic acid (4), secalonic acid D (5), altersolanol A (6), and ergosterol (7), were isolated from P. oxalicum. Altersolanol A (6) and secalonic acid D (7) exhibited outstanding cytotoxic activity against Hep-G2 and Caco-2 cell lines, with IC₅₀ values ranging from 0.00038 to 0.208 μM. In silico study findings showed altersolanol A (6), 4-hydroxyphenyl acetic acid (4), glycerol monolinoleate (3), and barcelonyl acetate (2) displayed significant potential but may benefit from further optimization as lead for developing potent c-Jun N-terminal kinase 2 (JNK2, PDB: 3NPC) inhibitors, potentially leading to novel therapeutic strategies targeting cancer therapy.

The rice husk biomass remaining from the industrial processing of rice constitutes approximately 25 wt% of the edible rice produced, and its disposal is challenging due to its high silica content. Here, we describe the optimization of a single step innovative chemical process for the conversion of rice husk-based biomass into useable products which tackles all fractions of the input biomass. The chemical process consists of a single step hydrothermal low temperature treatment of rice husk biomass leading to three easy-to-recover fractions. With appropriate chemical treatments, each of these fractions can serve specific applications effectively, overcoming the issues present in the original biomass. This paper will present the treatment method and the optimization of chemical conditions for ideal fractionation as well as include the characterization of the recovered materials. Additionally, the paper will explore the use of one of these materials—the inorganic precipitate fraction (P), which is rich in calcium silicate hydrate (C–S–H) phase—as an additive to promote C–S–H nucleation in cementitious materials. The process also yields a liquid fraction (S) rich in sugars and soluble inorganic species, and a fibrous fraction (HR) containing lignin and cellulose residues. All these components were characterized to assess their suitability for potential applications. A detailed study on the application of these materials in the fields of plant biology and polymer science will be presented in (a) subsequent publication(s). The three fractions were characterized by a multi-technique approach involving PXRD, XRF, TGA/DSC, Electron microscopy and NMR. The above chemical process can be extended to any straw and husk-based cereal crops (wheat or barley), broadening and strengthening the bio-based industries and improving the circularity of food-related byproducts.

Different CeO₂ nanostructures were synthesized using a hydrothermal method and treated with alkaline NaOH, followed by drying at 120 °C for 16 h and calcined at 400 °C for the direct oxidation of kenaf stalks to vanillin under microwave irradiation. The catalysts were characterized for their physicochemical properties using XRD, BET, Raman spectroscopy, TPR, TPO, and XPS. All synthesized CeO₂ nanostructures show diffraction peaks corresponding to the formation of cubic fluorite, which agrees with Raman spectra of the F_2g mode. The N₂ adsorption–desorption isotherms showed that all catalysts possess a type IV isotherm, indicating a mesoporous structure. TPR and TPO analyses display formation peaks corresponding to surface-to-bulk reducibility and the oxidized oxygen ratio, which is responsible for the redox properties of ceria nanostructures. The XPS analysis of CeO₂ nanostructures proved that Ce exists in the Ce³⁺ and Ce⁴⁺ oxidation states. All catalysts were tested for direct oxidation of kenaf stalks under microwave irradiation with the highest vanillin yield obtained by the CeO₂-Nps-400 heterogeneous catalyst at 3.84%, whereas 4.66% vanillin was produced using 2 N NaOH as a homogeneous catalyst.

The development of biocompatible antibacterial films plays a crucial role in the fight against antibiotic-resistant bacteria strains. Here, we developed an SBA-15–NH₂ decorated biocompatible CMC/PVA film containing Ag NPs as an antibacterial material against Gram-positive and Gram-negative bacteria strains. The structure of the manufactured film was studied by XRD, SEM, mapping, and TGA analysis showing its formation and firm structure. The prepared film has a flexible structure which makes it suitable for a variety of bio-related applications. The CMC/PVA/SBA-15–NH₂@AgNPs film was used as a bactericidal agent against pathogens (especially MRSA; methicillin-resistant Staphylococcus aureus) isolated from surgical site infections, showing promising results.

Fuel cells, one of the clean energy sources, is quite remarkable for energy production. In this context, catalysts are needed for the electrochemical reactions of DMFCs (direct methanol fuel cells) to work efficiently. In this study, Pt and Pt@Ti-MOF (Pt@MIL-125) NPs (nanoparticles) catalysts were synthesized by chemical synthesis. The Ti-MOF (MIL-125) structure was synthesized using the solvothermal method, and the effect of Ti-MOF on methanol oxidation was investigated. The results showed that Pt@Ti-MOF NPs provided 9.45 times more electrocatalytic activity for methanol oxidation compared to Pt NPs. In addition, Ti-MOF doping was shown to increase the stability and durability by long-term tests. The study provides important results on how MOF-supported structures behave electrochemically. The results show that Ti-MOF provides very high potential in MOR applications and is promising for use as an anode catalyst in DMFC systems.

Organic semiconductor devices have a lower intrinsic carrier density than inorganic semiconductors, and improving their electrical conductivity is important for organic electronic devices. Further theoretical investigations and understanding the properties of these electronic devices are necessary to improve the electrical conductivity of organic devices. In this study, we demonstrate how two carbon-material-assisted organic semiconductor devices affect the electrical conductivity and charge mechanism by using electrical measurements (i.e., I–V and C–V measurements, and numerical simulations). To clearly demonstrate the enhancement of the charge injection into TIPS (6,13-bis(triisopropylsilylethynyl)-pentacene), we studied the blending effect of carbon materials (carbon nanotube and fullerene) in TIPS and discussed injection, transport and charge accumulation of hole and electron in relation to trapped charge. This study will be helpful for understanding charge mechanisms in composite organic semiconductor devices.

Correction for ‘Design, synthesis, pharmacological evaluation, and in silico studies of the activity of novel spiro pyrrolo[3,4-d]pyrimidine derivatives’ by Abdullah Y. A. Alzahrani et al., RSC Adv., 2024, 14, 995–1008, https://doi.org/10.1039/D3RA07078F.

In this work, ZnO nanoparticles (NPs) are synthesized using avocado seed extract and annealed at different annealing temperatures from 400 to 800 °C. The morphology of the nanoparticles changes from poly shapes at 400 °C to spherical ones at 800 °C, and particle sizes increase from ∼42 nm to ∼128 nm. The Ag/ZnO@400/FTO memory device exhibits stable resistive switching over 100 cycles and a resistance window of approximately 150. Also, the performance characteristics of ZnO@600 and ZnO@800-based devices are degraded gradually over operating cycles. The concentration of oxygen interstitials (O_i) in ZnO nanoparticles, which may originate from organic residues, decreases as the annealing temperature increases. These O_i ions reduced the energy barrier at the interfaces, facilitating electron transport under an external electric field. This study has demonstrated the close correlation between resistive switching characteristics and organic residuals in green synthesized nanoparticles.

The endogenous neurosteroids dehydroepiandrosterone sulfate (DHEAS) and pregnenolone sulfate (PS) are allosteric modulators of γ-aminobutyric acid type A (GABA_A) and N-methyl-D-aspartate (NMDA) type glutamate receptors. Analogues of these endogenous steroid sulfates can be either positive or negative allosteric modulators (PAMs or NAMs, respectively) of these receptors, but there is limited information about the steroid-protein binding interactions that mediate these effects and photoaffinity labeling reagents (PALs) of sulfated steroids have not been reported previously. The synthesis of a panel of ten sulfated steroid analogues containing a diazirine group, five of which also contain an alkyne group for click chemistry reactions, for use in photoaffinity labeling studies to identify binding sites for steroid sulfates that are either positive or negative allosteric modulators is reported. Electrophysiological measurements on cultured rat hippocampal neurons were made to determine the modes of allosteric modulation in comparison to those of PS on both receptors. PALs with the activity profile of PS (NMDA PAM, GABA_A NAM) were identified. Unexpectedly, PALs with PAM activity at both receptors were also found. Photolabeling of both receptors by two of the PALs was performed to demonstrate their utility, and by inference those of the other PALs, for future studies to identify binding sites for endogenous steroid sulfates on both receptors.