The global pursuit of sustainable and renewable energy sources has intensified research into biomass-derived biofuels. Among various feedstocks, discarded coconut water, primarily associated with fully developed fruits, constitutes a sustainable byproduct abundant in fermentable sugars that can be converted into bioethanol fuel. This study explored the potential of converting mature coconut water, supplemented with molasses and inoculated with Saccharomyces cerevisiae yeast, into bioethanol. The fermentation process achieved an initial bioethanol concentration of 25% v/v (150 g yeast, 6 days fermentation). Subsequent distillation steps concentrated the ethanol to a high purity of 98.74% v/v, despite a decrease in distillate volume. Physicochemical analyses indicated bioethanol with a density of 0.9218 g/mL, viscosity of 1.08 cP, and turbidity within acceptable ranges. The chemical composition showed ethanol as the predominant substance, exceeding 95%, with minor amounts of acetic acid and aldehyde compounds. The presence of residual sugars in coconut water positions it as a valuable raw material for high-grade bioethanol synthesis, aiding in sustainable fuel development, although the low sugar content highlights the importance of process improvements.
Graphene, a remarkable material with extraordinary properties, has revolutionary potential for various technological applications. However, conventional methods of graphene production often involve energy-intensive and polluting processes. To address this challenge, we propose a sustainable approach that combines the production of high-quality graphene from recycled battery waste and its integration into nanofluids. Thanks to a simple and scalable electrochemical exfoliation technique, it is possible to obtain graphene with superior properties. The present study focuses on the large-scale preparation of graphene by recycling graphite from energy storage devices using a simple and inexpensive electrochemical technique. Characterization of the obtained materials was carried out by Raman spectroscopy, X-ray diffraction, specific surface area analysis, and scanning electron microscopy. The viscosity measurement and analysis of a graphene–water nanofluid were carried out at different temperatures and volume fractions. All viscosity measurements were carried out using a capillary viscometer at temperatures between 25 and 65 °C. The nanofluid showed increasing viscosity with increasing nanoparticle concentration and decreasing viscosity with increasing temperature.
In this study, the heterogenous photocatalytic degradation of the azo food dye tartrazine (TRZ) was investigated using a TiO 2 catalyst under UV light in contaminated water. A Box–Behnken experimental design with three factors at three levels was applied, considering pH, catalyst mass, and dye concentration as the main variables. The response was the TRZ photodegradation rate (%), statistically controlled by ANOVA and response surface method (RSM). The model developed demonstrated a strong correlation between predicted and experimental values. Furthermore, a kinetic study was carried out to determine the reaction order and rate constants, and a photocatalytic degradation mechanism was proposed. The optimal values of the operating conditions were found: pH 5.7, TiO 2 mass 48.4 mg, and dye concentration 5 mg/L, corresponding to a photodegradation rate of 89.3% as predicted by the model, with a coefficient of linear regression around R 2 = 98.9%.
In recent years, hydrothermal carbonization (HTC) has transitioned from a laboratory-scale process to a demonstrated technology for valorizing citrus waste. This review synthesizes post-2015 experimental studies and critical analyses, focusing on the real-world applicability of HTC for citrus peels and pomace. The assessment covers energy carriers, water treatment, soil amendment, aqueous phase valorization, and advanced materials. Quantitative benchmarking reveals strong progress in fuel pellet specification compliance and adsorption performance, supported by pilot-scale continuous operation and life cycle assessment (LCA). Key findings indicate that continuous HTC of orange peels can produce hydrochar pellets meeting industrial fuel standards, with improved ash behavior and higher heating value (HHV). Process water recirculation enhances solid mass yield, while anaerobic digestion (AD) of the aqueous phase achieves high chemical oxygen demand (COD) removal and near-theoretical methane yields. However, gaps remain in standardized reporting, field-scale agronomic trials, and techno-economic analyses for adsorption applications. This synthesis underscores the maturity of citrus-waste HTC for energy applications and highlights the need for integrated system analyses to fully capitalize on its biorefinery potential within a circular economy framework.
Ce travail explore le développement de films bioplastiques à base d’amidon extrait des pelures de pomme de terre, renforcés par deux biomatériaux naturels issus de déchets agro-industriels : la pectine extraite des pelures d’orange et la nanocellulose isolée de la paille. Les propriétés thermiques, mécaniques, hydriques et biodégradables des formulations ont été étudiées afin d’évaluer l’influence de ces renforts sur les performances globales des bioplastiques. Les résultats montrent que l’incorporation de pectine améliore la rigidité, la résistance mécanique et la stabilité thermique des films, tandis que la nanocellulose renforce la structure mais requiert une meilleure dispersion pour un effet optimal. Les essais d’absorption et de biodégradation en milieux naturels (sol et eau de mer) confirment la sensibilité hydrophile et la dégradabilité rapide des films, démontrant leur potentiel environnemental. En comparaison avec les plastiques conventionnels, ces bioplastiques biosourcés constituent une alternative durable et écologiquement avantageuse. Enfin, des perspectives d’optimisation sont proposées, notamment l’amélioration de la dispersion des renforts, l’adaptation à d’autres matrices polysaccharidiques et l’évaluation de leurs performances en contexte industriel.
Electrochemiluminescence (ECL) has evolved into a cornerstone of modern bioanalytical science, primarily due to the development of coreactant-based systems that enable highly sensitive detection in aqueous media. The performance of these systems is fundamentally governed by the transient radical intermediates generated from the coreactants themselves. This review provides a critical examination of these pivotal species, focusing on the two most significant and mechanistically distinct coreactant classes: tertiary amines, exemplified by tri- n -propylamine (TPrA), and persulfate. We delve into the complex and often contentious mechanistic pathways of radical generation, dissecting the long-standing debate between direct oxidation and catalytic routes for the TPrA system and exploring the emerging evidence for non-radical pathways in persulfate chemistry. A comprehensive overview of advanced analytical techniques is presented, highlighting how methods such as electron paramagnetic resonance (EPR) spectroscopy, real-time mass spectrometry, and high-resolution ECL microscopy have been instrumental in detecting and characterizing these fleeting radicals, thereby providing the experimental foundation for mechanistic elucidation. Finally, we establish a direct link between the fundamental physicochemical properties of these radical intermediates and the ultimate performance of ECL-based bioanalytical platforms, including sensitivity, selectivity, and robustness. By synthesizing the current state of knowledge and identifying key unresolved questions, this review aims to provide a nuanced understanding of coreactant radical intermediates and to chart a course for the future rational design of next-generation ECL systems.
Phosphorus dendrimers are highly branched, monodisperse macromolecules built around a phosphorus core, and having phosphorus atoms at all branching points. Their modular architecture allows for precise control over size, shape, and surface functionality. When functionalized at the surface with heterocycles—organic rings containing one or more heteroatoms (e.g., nitrogen, oxygen, sulfur)—these dendrimers gain catalytic activity, in the materials or biological fields. This review is organized according to the type of heterocycles (including N, O, S, or combined heteroatoms) linked to the surface of phosphorus dendrimers and emphasizes their properties.
Coordinative Chain Transfer Polymerization, or CCTP, has gained much interest in the last years. This can notably be ascribed to its ability to allow catalyst economy, but also the design of original polyolefinic microstructures. Group 10 metals such as Ni were much less studied for CCTP comparatively to other metals. Indeed, the β-H transfer/elimination processes associated to these metals can be considered at first glance as a significant drawback in the realm of CCTP. In this perspective, we discuss this paradox and highlight the peculiar role played by Ni catalysts for CCTP reactions, both as polymerization and chain displacement catalysts, and highlight its implications for molecular and macromolecular engineering.
Supramolecular dendrimers formed through the self-assembly of amphiphilic dendritic building blocks have emerged as powerful nanoplatforms that combine dendritic architectural features with dynamic adaptability. In contrast to conventional covalent dendrimers, self-assembling supramolecular dendrimers are readily accessible, structurally tunable, and capable of forming functional nanomicelles with large internal voids and multifunctional surfaces, enabling efficient drug and nucleic acid delivery as well as advanced biomedical imaging. This short Account summarizes our decade-long dedication to engineering self-assembling supramolecular dendrimers for biomedical applications, with a particular emphasis on molecular engineering that governs self-assembly, pharmaceutical agent loading and release, biodistribution, and biomedical performance. Collectively, our studies establish self-assembling supramolecular dendrimers as versatile and programmable platforms for next-generation nanomedicine.
We present theoretical investigations of 2D raft-type heterometallic clusters [MMoCp(or C5H4NMe2)(CO)(3)](n) (M = Cu, Ag, Au) with a triangular (n = 3) or square (n = 4) copper, silver, or gold core edge-bridged by three or four metalloligands MoCp(or C5H4NMe2)(CO)(3), respectively (Cp = eta(5)-C5H5; C5H4NMe2 = eta(5)-C5H4NMe2). Various molecular symmetries, C-1, C-s, C-2, D-2, and S-4, were considered, and our calculations reveal an excellent agreement between the most stable computed structures and those determined experimentally by X-ray diffraction when the Cp ligand is used. In contrast, clusters incorporating the C5H4NMe2 ligand display alternative geometries that are energetically more stable than those found experimentally, emphasising the crucial role of the pi-bound ligand on cluster stability. For M = Cu, we demonstrate that square cores with elongated Cu-Cu distances can be stabilised, consistent with previously described systems. Energy decomposition analysis (EDA) at the BP86 level shows that the Cu, Ag, and Au clusters are stabilised by a strong interplay of electrostatic and orbital interactions, with markedly stronger binding in the tetranuclear systems due to cooperative metal-metal and metal-ligand effects. Frontier molecular orbital analysis was used to investigate the electronic structure and potential reactivity of these clusters. The results reveal that metal nature, NMe2 substitution, and cluster nuclearity strongly affect the HOMO-LUMO gaps and charge-transfer behaviour. NMe2-substituted Cu and Au clusters with higher nuclearity display reduced HOMO-LUMO gaps and greater frontier orbital delocalisation, indicating an increased propensity for redox processes. Our theoretical study satisfactorily reproduces the experimental structures of these 2D raft-type heterometallic clusters and highlights the possibility of uncovering new potentially accessible geometries of transition-metal clusters.
In this paper, we report the synthesis, structural, vibrational, and optical characterization of the BaSb0.5Fe0.5(PO4)(2) compound, prepared via the conventional solid-state reaction method. X-ray powder diffraction analysis, followed by Rietveld refinement, revealed that the material crystallizes in the monoclinic system with the C C2/m space group and Z = 2, consistent with a yavapaiite-type structure. Scanning electron microscopy was employed to examine the microstructure and confirm elemental homogeneity. Raman and infrared spectroscopy were used to investigate the internal modes of the phosphate units, providing evidence for well-defined PO43- tetrahedra and confirming the integrity of the crystal framework. UV-visible spectroscopy measurements indicated both direct and indirect optical band gap energies of 2.96 and 3.28 eV, respectively, suggesting that BaSb0.5Fe0.5(PO4)(2) behaves as a semiconducting material. The combination of a well-ordered crystal structure, vibrational stability, and semiconducting properties highlights the potential of this phosphate-based compound for applications in optoelectronic devices and functional materials.
This work investigates the conversion of orange peel waste into effective biomaterials. Two pectins were first extracted from these peels under acidic conditions using citric acid (PCT-1) or hydrochloric acid (PCT-2), then thoroughly characterized and finally tested for biomedical applications. The characterization of pectin was carried out using various analytical techniques including Fourier-transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and differential scanning calorimetry. The biomedical application of the extracted pectins demonstrates that neither PCT-1 nor PCT-2 have an antibacterial effect on Pseudomonas aeruginosa or E. coli. Nevertheless, a significant antibacterial effect was observed on the Staphylococcus epidermidis strain. This highlights their potential use for the treatment of some infectious diseases and particularly against Gram-positive strains. Besides, the extracted pectins exhibit a high potential use as antioxidants. Although PCT-2 does not display marked anticoagulant activities, PCT-1 shows an interesting potential to be valorized as an anticoagulant. All these results show that pectins extracted from orange peel waste can be valorized as effective biomaterials with numerous biomedical applications.
Herein, we report a straightforward protocol for synthesizing 4-(methylthio)-3-phenyliso-quinolines, which are valuable compounds in medicinal chemistry for their biological activities. This method uses 1-(azidomethyl)-2-(phenylethynyl)benzenes and dimethyl(methylthio)sulfonium trifluoromethanesulfonate (DMTSM) under mild, metal-free conditions. Notably, it tolerates diverse aromatic functional groups, enabling derivative preparation. The reaction proceeds smoothly, affording products in good to excellent yields. By avoiding hazardous and malodorous methylthio radical reagents as well as methylthio nucleophile precursors, this protocol provides a practical and ecofriendly route to sulfur-containing heterocycles.
This study aimed to valorize grape seed residues from the wine industry by characterizing cold-pressed grape seed oil obtained from five Vitis vinifera L. varieties ("Malbec", "Syrah", "Italia", "Moscatel", and "Criolla") collected in Arequipa, Peru. The structural and chemical characteristics of the grape seeds were analyzed using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). The fatty acid composition of the recovered oil was determined by gas chromatography-mass spectrometry (GC-MS), total phenolic compounds (TPC) were quantified using the Folin-Ciocalteu method and antioxidant capacity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Microbiological quality and a preliminary cost analysis were also assessed. The average oil yield obtained by cold pressing was 9.06% (90.64 g/kg of seeds). FTIR analysis confirmed the presence of functional groups mainly associated with lipids (C=O and C-H) and phenolic compounds (O-H), while GC-MS revealed that the oil was mainly composed of linoleic acid ethyl ester (64.40%), ethyl oleate (11.83%), and hexadecanoic acid ethyl ester (10.14%). Among the evaluated varieties, Syrah oil exhibited the highest total phenolic content (143.84 mg gallic acid equivalent/kg) and the highest antioxidant activity. Overall, DPPH radical scavenging values ranged from 33% to 46% among the analyzed oils. No microbiological growth was detected in the oil samples. The estimated production cost of grape seed oil was 25.58 USD per liter. These findings indicate that grape seed residues represent a sustainable source of value-added oil with antioxidant properties, which supports their potential application within a circular economy framework.
The synthesis of branched alpha-olefins employing the diversely available and inexpensive feedstock ethylene is challenging. The recently reported elongation and branching reaction of alpha-olefins by two ethylene molecules and the identification of more selective catalysts for this reaction permit the multigram synthesis of mono-and dibranched alpha-olefins. We report here the synthesis of 4-ethyl-1-octene, 4-ethyl-1-decene and 4-ethyl-6-methyl-1-heptene. The key is the long-term stability of the catalyst employed.
The synthesis of dendritic architectures has steadily advanced to overcome challenges associated with biological applications. Key issues-including reduced toxicity, enhanced target specificity, improved stability, and efficient delivery of drugs, vaccines, and genes-have posed significant hurdles, particularly when scalability for therapeutic translation is required. Among these, optimizing dendrimer systems to engage in carbohydrate-related biological functions has remained a central focus since the introduction of glycodendrimers. The emergence of glycodendrimers has proven especially effective in contexts demanding multivalent binding interactions. This review highlights advancements in the design of multivalent carbohydrate-based nanomaterials, tracing their evolution from the early development of glycopolymers to the emergence of glycodendrimers. It presents key developments in the use of scaffolds featuring an expanded array of surface functional groups alongside variations in the chemical building blocks traditionally employed in classical dendrimer synthesis-culminating in the so-called "onion-peel strategy". These innovations are further complemented by the integration of orthogonal ligation techniques. Additionally, efforts to streamline the synthesis of multivalent glycoarchitectures have led to the emergence of simplified methodologies, including transition-metal-templated assembly and the self-organization of glycodendrimersomes.
The presence of micropollutants, such as pharmaceuticals, in aquatic environments is a major concern due to the risks they pose to living organisms. Given the often inadequate management of wastewater, it is crucial to develop reliable and effective methods to eliminate these contaminants, thus ensuring our safety and protecting the ecosystem. This study aims to test the ability of a polyvinyl chloride/graphene oxide (PVC/GO) composite membrane to adsorb metformin (Met) in an aqueous solution. The graphene oxide was synthesized using the Hummers method from recycled graphite obtained from drilling molds, thereby adding an ecological dimension to this research. This graphene oxide was then used to prepare PVC/GO. The resulting materials were characterized using Fourier-transform infrared spectroscopy, thermogravimetric analysis and Brunauer-Emmett-Teller analysis. The following adsorption parameters were investigated: pH (2-8), temperature (25-40 degrees C), time (5-30 min), GO content in PVC/GO (0-15%) and initial concentration (4, 6, 8, and 10 mg/L). Adsorption experiments revealed that 75% removal of Met was achieved within 15 min at an optimum concentration of 4 mg/L. Maximum adsorption efficiency of Met was obtained at 40 degrees C in an acidic medium (pH 2); however, adsorption decreased as the pH increased. Thermodynamic studies indicated that Met adsorption was spontaneous (triangle G degrees < 0) and exothermic (triangle H degrees < 0) at 25, 30, and 35 degrees C. However, the process was endothermic and non-spontaneous at 40 degrees C. Based on the obtained results, PVC/GO 5% was found to be an efficient and promising adsorbent for Met.
This study explores various approaches to enhancing the activity and selectivity of gas-phase photocatalytic CO2 reduction under humid conditions by implementing and optimizing bimetallic M-Cu systems (M = Pt, Pd, Au, Ag) supported on titanium dioxide (TiO2). By tuning the total metal content, the molar ratio between M and Cu, the deposition method, and the nature of the TiO2 support, it is possible to create a synergy between copper and the secondary metal, each contributing its own advantages while minimizing drawbacks. This strategy also improves the stability of the systems by increasing their resistance to Cu oxidation. These results offer a promising pathway for the development of efficient photocatalysts for solar-driven gas-phase CO2 conversion into chemical fuels.
