Sustainable Chemistry

Natural deep eutectic solvents (NADES) are gaining interest as environmentally friendly alternatives to conventional organic solvents in the functional food sector. Their low volatility, biodegradability, and tunable polarity, combined with high affinity for phenolics, carotenoids, and other phytochemicals, make them particularly relevant for developing antioxidant and anti-inflammatory ingredients at a time of rising diet-related chronic disease burden. This review critically analyses the role of NADES along the functional food chain. We summarize their composition, preparation, and key physicochemical properties, and then examine the NADES-based extraction of antioxidant and anti-inflammatory compounds from plants and food by-products in comparison with traditional solvent systems. The influence of NADES on the stability and biological activity of recovered compounds is discussed, together with their use in the formulation, stabilization, and delivery strategies for functional foods. Emerging data indicate that NADES often enhance extraction yields and may protect labile bioactives, leading to stronger antioxidant and anti-inflammatory responses in vitro compared with ethanol or water extracts when normalized to phenolic content. At the same time, large-scale implementation is limited by challenges related to safety assessment, regulatory acceptance, viscosity, and recovery issues, and incomplete techno-economic data. This review highlights these constraints, identifies key knowledge gaps, and outlines research priorities required to translate NADES-based processes into scalable, safe, and health-promoting functional food applications. Full article

Semiconductor manufacturing is a resource and energy-intensive industry with a substantial environmental footprint. To address the footprint, we present a methodology for quantifying the environmental impact of semiconductor unit processes using the Environmental Footprint 3.1 Life Cycle Impact Assessment (LCIA) framework, focusing on identifying improvement opportunities in process steps with less sensitivity to defects. We apply this methodology to backside wet cleaning by proposing an alternative single-wafer process that adopts ozonated chemistries. The assessment used primary data from imec’s 300 mm pilot line. Results show that the proposed process reduces the total environmental footprint by 55% compared to the baseline Spin Cleaning with Repetitive use of Ozonated water and Diluted HF process. Key reductions include 67% less electricity for cleaning, 59% less HF use, and a 31% reduction in ultrapure water consumption. When scaled to a facility producing N28 Logic wafers at 50,000 wafer starts per month, with 46 backside clean steps per processed wafer, the process achieves annual savings of approximately 4 million kWh of electricity and 28 million liters (28,000 m³) of tap water per year. A sensitivity analysis revealed that replacing fossil-based electricity with hydroelectric power further reduces total environmental impacts by up to 63%, emphasizing the benefit of combining process innovation with renewable energy sourcing. Full article

Accurate prediction of the Langelier Saturation Index (LSI), an indicator of water’s scaling and corrosive potential, is vital for water treatment and infrastructure maintenance. In this study, five machine learning models (Ridge Regression, Support Vector Machine, Random Forest, Deep Neural Network, and XGBoost) were applied to predict the LSI from physicochemical characteristics of groundwater in the Morava River basin (Serbia). Rigorous data preprocessing (outlier removal, missing data handling, z-score normalization) and feature selection were performed to ensure robust model training. Models were optimized via 10-fold cross-validation on a 70/30 train–test split. All models achieved high predictive accuracy, with ensemble methods outperforming others. XGBoost yielded the best performance (R² = 0.98; RMSE = 0.06), followed closely by Random Forest (R² = 0.95). The linear Ridge model showed the lowest (yet still strong) performance (R² = 0.90) and larger errors at extreme LSI values. Feature importance analysis consistently identified pH as the most influential predictor of the LSI, followed by alkalinity and calcium. Partial dependence plots confirmed that the models captured established nonlinear LSI behavior. The LSI rises steeply with increasing pH and moderately with mineral content. Overall, this comparative study demonstrates that modern machine learning models can predict the LSI accurately, providing interpretable insights through feature importance and dependence plots. These results underscore the potential of data-driven approaches to complement traditional water stability indices for proactive water quality management. Full article

A sustainable circular pathway was developed for poly(ethylene terephthalate) (PET) nanocomposites through a catalyst-driven polymerization and depolymerization process. In this study, calcium dodecylbenzene sulfonate with n-butyl alcohol modified ZnAl layered double hydroxides (LDHs) were utilized as bifunctional catalysts to synthesize highly exfoliated PET/LDH nanocomposites via in situ polycondensation of bis(2-hydroxyethyl) terephthalate (BHET). The organic modification of LDHs expanded interlayer spacing, improved interfacial compatibility, and promoted uniform dispersion, leading to enhanced mechanical, thermal, and barrier properties. In the second stage, the pristine LDH catalyst efficiently depolymerized the prepared PET/LDH nanocomposites back into BHET through glycolysis, completing a closed-loop BHET-to-BHET cycle. This integrated strategy demonstrates the reversible catalytic functionality of LDHs in both polymerization and depolymerization, reducing metal contamination and energy demand. The proposed approach represents a sustainable route for designing recyclable high-performance PET nanocomposites aligned with the principles of green chemistry and circular material systems. Full article

This work used activated carbon material obtained by chemical activation of abundantly available agricultural sunflower waste residues to remove metol (4-(methylamino) phenol sulfate, MTL) from aqueous solutions. The adsorbent structure was characterized using SEM-EDS and FT-IR spectroscopy. A modified screen-printed carbon electrode (SPCE) with gold nanoparticles synthesized using the Laser Ablation Synthesis in Solution (LASIS) method was used to detect MTL. The successful LASIS formation of gold nanoparticles was confirmed by the specific dark burgundy–red color. TEM measurements showed uniform pseudo-spherical particles with an average diameter of 7.9 ± 0.2 nm. The modified electrode showed improved electrochemical activity, which was confirmed by comparing it with an unmodified electrode using cyclic voltammetry and electrochemical impedance spectroscopy. The modified electrode was subsequently used to optimize the MTL detection conditions. UV–Vis spectroscopy was used to optimize the adsorption conditions, with the optimal values for pH and contact time found to be 8 and 120 min, respectively. The electrochemical detection of MTL was performed using differential pulse voltammetry, and the linear calibration range was established for concentrations ranging from 0.73–49.35 µM. The obtained limits of detection (LOD) and quantification (LOQ) were 0.06 µM and 0.2 µM, respectively. The efficiency of MTL removal was 100% after a contact time of 1 min and remained at 100% after 120 min. Full article

Biogenic nanoparticles have recently emerged as promising bacterial growth inhibitors, requiring low concentrations and not producing harmful byproducts. However, knowledge gaps remain regarding how different extraction techniques affect nanoparticle synthesis, thereby influencing their replicability and scalability across various applications. To address these knowledge gaps, this study compared six extracts derived from Moringa oleifera biomass for the synthesis of iron oxide nanoparticles. Multivariate statistical analyses correlated extraction methods with biomolecule content (polyphenols, flavonoids, carbohydrates, proteins), iron percentage, and E. coli growth inhibition. All extracts showed varying concentrations of biomolecules, and different extraction methods were preferable for specific components. Flavonoids were best extracted by salting-out, while infusion methods were better for obtaining carbohydrates. Higher percentages of iron (22.77%) were linked to the presence of polyphenols and flavonoids. Nanoparticles prepared using salting-out and infusion extraction from leaf biomass displayed the highest efficiency in inhibiting E. coli growth, up to a dilution factor of 4. The outcomes of this research study provide an in-depth understanding of the role of specific biomolecules in biogenic nanoparticle synthesis, confirming that both synthesis yield and application effectiveness depend on the extract preparation method. Full article

Water-based drilling fluids (WBDFs) are widely used due to their economic and environmental advantages; however, shale hydration remains a major limitation. This study evaluates Fe₂O₃, CuO, ZnO, and MgO nanocrystalline metal oxides synthesized via co-precipitation as inorganic shale inhibitors for WBDFs. Comprehensive characterization confirmed phase-pure nanocrystalline oxides (17–38 nm) with high thermal stability. Performance tests revealed that MgO-based WBDF exhibited the lowest plastic viscosity (17 cP), the highest pH (≈10.0), and the strongest shale inhibition (6.1% swelling), while Fe₂O₃ provided superior filtration control (6.0 mL). CuO showed balanced rheology, whereas ZnO displayed comparatively weaker inhibition. Compared with commercial inhibitors (Amine NF and Glycol), MgO- and Fe₂O₃-based systems achieved comparable or improved performance with enhanced thermal and environmental robustness. These results demonstrate the potential of nanocrystalline metal oxides as sustainable additives for improving WBDF performance under high-pressure, high-temperature (HPHT) conditions. Full article

This study investigates amorphous anodized porous TiO₂ (a-TiO₂) as a substrate for iridium-based oxygen evolution catalysts. The substrates were prepared via anodization of Ti foil in a glycerol-based solution for 15 min @ 60 V. Nickel was subsequently electrodeposited to act both as a conductive and sacrificial layer for the galvanic deposition of iridium from an Ir(IV) chloro-complex solution. Electrochemical anodization resulted in a uniform IrO_x layer on the a-TiO₂ substrate, featuring Ir aggregates ~250 nm in size and an Ir:Ni atomic ratio of ca. 7, as determined by EDS analysis. The quantity of Ni determined by ICP-MS bulk analysis indicated that Ni resided also within the porous matrix. Varying the Ni deposition charge density (q_Ni) revealed that an intermediate loading (1463 mC cm⁻²) provided the best balance between Ir accessibility during the galvanic replacement step and electronic continuity. The optimized IrO_x/Ir-Ni/a-TiO₂ electrode achieved excellent OER performance (η = 344 mV @ 10 mA cm⁻²; 1.68 mA μg_Ir⁻¹ @ η = 300 mV) at an ultra-low Ir loading of 2.15 μg_Ir cm⁻² and demonstrated good short-term stability, with only a 20 mV potential increase over 4 h of continuous operation at 5.5 mA cm⁻². Overall, this strategy offers a scalable pathway for producing efficient OER electrodes with minimal noble metal loading. Full article

In whey valorization, membrane separation stands out as a highly effective technique for purifying and isolating the various components of whey. The efficiency of whey ultrafiltration and diafiltration (UF/DF) largely depends on the balance between membrane selectivity, hydrodynamic conditions, and solute interactions at the membrane interface. In this study, sweet whey was fractioned using 10, 30 and 50 kDa polyether sulfone (PES) membranes under identical transmembrane pressure (TMP = 2.5 bar) with ultrafiltration and a subsequent 4-step constant volume diafiltration stages. The resulting compositional and dielectric changes were evaluated to identify optimal separation conditions and assess the applicability of dielectric parameter measurement as a rapid, non-destructive monitoring technique. Results showed that, regardless of the applied molecular weight cut-off (MWCO), using three DF cycles can wash out almost all the removable lactose from the retentates, and the dielectric assessment of both permeate and retentate fractions showed a strong, linear relationship between the change in dielectric behavior and the composition of each fraction. Analysis of the dielectric spectra confirmed that the ratio of the dielectric constant to the loss factor (ε′/ε″) exhibited a strong linear correlation (R² > 0.98, r > 0.99) with lactose concentration in the permeate fractions of all three MWCO membranes, as well as a similarly strong correlation (R² > 0.975, r > 0.98) with the total chemical oxygen demand (TCOD) measured in the retentate fractions. Full article

The old spectral displacement method can be suitably revitalized for a didactic experimental approach to fundamental concepts of supramolecular chemistry and to the study of complex equilibria in general. In particular, the case of the β-cyclodextrin/phenolphthalein/adamantane ternary system has been taken into account as a viable and impressive example due to the remarkable color changes that can be observed when performing the experiments. A new method for data regression analysis is proposed, with a smart trick able to overcome the mathematical difficulties arising whenever multiple equilibria must be considered. Hence, some aspects of the reliability of fitting procedures are discussed. Full article

Mercury (Hg²⁺) contamination in water systems poses a severe environmental and health hazard due to its high toxicity and bioaccumulation potential. In this study, a novel adsorbent was developed by sequentially modifying kaolin via acid–base treatment, titanium dioxide (TiO₂) incorporation, and 3-aminopropyltriethoxysilane (APTES) grafting. Batch adsorption experiments revealed that the fully modified kaolin (TiO₂-loaded and APTES grafted) exhibited the highest adsorption capacity (25.6 mg/g) compared to the acid–base-treated (5.8 mg/g) and TiO₂-loaded (17.7 mg/g) kaolin. Under optimal conditions (75 mg adsorbent dosage; 70 mg/L Hg²⁺; pH 5), the fully modified kaolin maintained its performance even in the presence of varying ionic strengths, natural organic matter, and competing metal ions. Adsorption kinetics followed a pseudo-second-order model, and the equilibrium data were well fitted by the Langmuir isotherm. Antibacterial activity assay revealed that the TiO₂-loaded kaolin effectively inhibited S. aureus (minimum inhibitory concentration = 2.5 mg/mL) and showed moderate activity against E. coli (BL21) (minimum inhibitory concentration = 5 mg/mL). However, antibacterial activity decreased after amine functionalization, indicating a compromise between enhancing adsorption capacity and preserving antibacterial functionality. This study presents a promising cost-efficient approach for the simultaneous removal of Hg²⁺ ions from water matrices and inhibiting bacterial growth, aligning with SDG 6 (Clean Water and Sanitation). Full article

Deep eutectic solvents (DES) were selected for the extraction of anthocyanins from red grape skins as an efficient and environmentally friendly solvent alternative to traditional mixtures based on methanol. In silico studies (COSMO-RS) were employed as screening tools to identify the most suitable options, significantly reducing the chemical space of potential DES to be studied. A total of 30,132 DES combinations were assessed. The DESs selected were polyalcohols (ethyleneglycol, glycerol, 1,2-propanediol, and 1,6-hexanediol) and carboxylic acids (citric, oxalic, malic, and lactic acid) as hydrogen bond donors (HBD) and choline chloride, betaine, or salts (potassium carbonate, sodium acetate, and propionate), as hydrogen bond acceptors (HBA). Choline chloride:glycerol and choline chloride:oxaclic acic were selected as solvents to optimize time, temperature, and water content in ultrasound- and microwave-assisted extraction of anthocyanins. In both cases, around 20 wt% of water was found to be the optimum to maximize the extractions, whereas extraction time and temperature depended on the type of anthocyanin. The amount of malvidin-3-O-glucoside extracted by microwave-assisted extraction with choline chloride: oxalic acid was 172 ± 7 mg/kg and 119.5 ± 0.5 mg/kg by ultrasound-assisted extraction with choline chloride: glycerol, which means an increase in performance of, respectively, 64 and a 13% compared to the traditional method. Full article

This interdisciplinary study explores the potential of bioactive compounds from Aronia melanocarpa pomace, a juice industry by-product. The ethanol extract of the pomace was analyzed using HPLC, revealing key polyphenolic acids and anthocyanins. The extract exhibited outstanding antioxidant activity (100% as measured by the ABTS assay and 98.23% as measured by the DPPH assay) and >99% antibacterial efficacy against E. coli and S. aureus. This bioactive extract was utilized in a one-step process to dye and functionalize textiles (wool, silk, cellulose acetate, cotton, and viscose), with cotton and viscose suited for colored disposable bioactive textiles, particularly protective healthcare textiles, due to strong antioxidant (>97% as measured by the ABTS assay and >76% as measured by the DPPH assay) and antibacterial (>75% for E. coli and >80% for S. aureus) properties. The aronia pomace extract was also incorporated into newly synthesized starch/gelatin hydrogels with a compression modulus of 0.041–0.127 MPa and equilibrium swelling ratios of 3.33–4.26 g/g. Functionalized hydrogels demonstrated over 99% ABTS antioxidant activity, while the antibacterial efficacy against E. coli and S. aureus exceeded 70% and 97%, respectively. These properties, combined with the hydrogels’ ability to control the release of extract compounds, make them adequate for wound care applications. The extract’s effectiveness as a green inhibitor for carbon steel, with inhibition efficiency surpassing 94% at a concentration of aronia pomace extract of 100 ppm, was confirmed by electrochemical methods. Moreover, the extract predominantly retards the cathodic reaction. The current research represents the first exploration of alternative and green sustainable technologies for developing novel products based on aronia pomace extract. Full article

The burning of coal in thermal power plants throughout Serbia produces significant amounts of industrial waste, primarily in the form of fly ash, boiler ash, and slag. Given their annual production, availability, and fine grain structure, it is necessary that sustainable strategies are developed for their reuse, instead of depositing them directly in landfills. In this research, the possibility of using fly ash, slag, and diatomaceous earth as raw materials for the synthesis of geopolymers at low temperatures was examined, in order to replace cement in construction materials, with the aim of reducing carbon dioxide emissions. Special emphasis was put on the effect of addition of organic macromolecules—polyvinyl alcohol (PVA), chitosan, and starch—upon the structure and mechanical properties of the obtained materials. In addition, the behavior of the materials with regard to the leaching of heavy metals in different environmental conditions was examined. Chemometric methods of multivariate analysis were used to examine the correlations between the obtained physical–chemical parameters, while the dependence of mechanical properties on the composition of the raw mixture was analyzed using the Mixture Design of Experiments method. The results obtained indicate that the examined waste materials have potential to be used as an environmentally friendly alternative to cement. The addition of PVA and chitosan had a positive effect on the mechanical properties of the geopolymers, with the highest strength achieved in formulations based solely on fly ash, containing 2.5% PVA, which reached 12.6 MPa. It was also shown that the addition of 30% diatomaceous earth increases the density and compressive strength of the material, while reducing the number of microcracks present in its structure, with a compressive strength of 13 MPa. Full article

Catalytic upgrading of bioethanol via a C–C coupling reaction is a sustainable method of producing 1-butanol, a high-performance biofuel. This reaction was studied using a flow-through microreactor system with Pd/MgO-Al₂O₃ and bimetallic Pd-Cu/MgO-Al₂O₃ mixed oxide-based catalysts in a H₂ carrier gas at a pressure of 21 bar and temperatures ranging from 200 to 350 °C. The effect of the metal promoter(s) on the hydrogen transfer reaction steps in the overall reaction was investigated. The palladium promoter significantly improved the activity and butanol selectivity across the entire temperature range. However, the yield of liquid products decreased significantly at temperatures higher than 250 °C, primarily because the decarbonylation side reaction of the acetaldehyde intermediate accelerated. The promoting effect of Pd was most beneficial below 250 °C because the decarbonylation reaction was inhibited by the reversible poisoning effect of CO on multiple Pd sites responsible for decarbonylation. Diluting the Pd phase with Cu increased liquid yields due to gradually decreasing decarbonylation activity. However, the dehydrogenation–hydrogenation activity decreased as well, as did the promoting effect on the corresponding reaction steps in the coupling reaction. Additionally, the product distribution changed dramatically, decreasing 1-butanol selectivity, because metallic Cu can catalyze the formation of ethyl acetate and ketone products. Full article

Ammonia, widely regarded as the “hydrogen carrier of the future,” offers high hydrogen content, ease of production, and a well-established infrastructure for handling and transportation globally. Meanwhile, ammonia cracking requires a heat supply at high temperatures, and induction heating provides efficient, precise, and rapid heating to conductive materials of different shapes and sizes. Therefore, this work presents a proof of concept for ammonia cracking using induction heating with three different reactor configurations: (1) a 3D metal workpiece; (2) a 3D metal workpiece and Ni/Al₂O₃ catalyst; and (3) only Ni/Al₂O₃ catalyst. The performance of the inductively heated reactor is also compared to an electric furnace. The results showed that the reactor with the workpiece and the catalyst required 97 W to reach 650 °C, being the most efficient in terms of power usage when compared to the workpiece alone and the electric tube furnace, which required 39% and 132% more, respectively; the least efficient configuration is with just the catalyst, needing 138 W to reach just 116 °C. Overall, the introduction of the 3D workpiece allowed for fast and uniform conversion and heating within the reactor, enabling efficient and dynamic process control when applying induction heating to chemical reactors. Full article

Mesoporous materials have attracted increasing attention due to their ordered pore systems; tunable surface chemistry; and versatile applications in catalysis, adsorption, and environmental technologies. Among them, SBA-15 stands out for its large surface area, uniform mesopores, and high hydrothermal stability, which make it a promising platform for gas adsorption and mass transport studies. This review examines the functionalization of SBA-15 through strategies such as post-synthesis grafting and co-condensation, focusing on the introduction of amines, thiols, and organometallic species that enhance selectivity, adsorption capacity, and thermal stability. The discussion integrates classical diffusion models, including Fickian and Knudsen transport, with more advanced approaches such as the Maxwell–Stefan formalism, to describe molecular transport within mesoporous networks and highlight the role of van der Waals interactions in gas capture processes. Special emphasis is placed on the relationship between structural features and diffusive behavior, supported by recent advances in computational modeling and spectroscopic validation. Applications in CO₂ capture, heterogeneous catalysis, drug delivery, and environmental remediation are critically assessed to illustrate the versatility of functionalized SBA-15. This review concludes by outlining future perspectives on the rational design of hierarchical and multifunctional mesoporous materials for clean energy conversion, pollutant removal, and biomedical applications. Full article

This study reports the solvent-free mechanochemical synthesis of a novel series of 2-hydrazone-bridged benzothiazole derivatives 19–52 via the reaction of 2-hydrazinylbenzothiazole derivatives 4–6 with O-alkylated benzaldehydes 7–18. The stereostructure of the E-isomers was confirmed by 2D NOESY spectroscopy. The antiproliferative potential of these newly prepared 2-hydrazone derivatives of benzothiazole 19–52 was evaluated in vitro against eight human cancer cell lines. Several compounds demonstrated low micromolar IC₅₀ values, with some outperforming the reference drug etoposide. Among the most potent compounds, the 6-chloro-2-hydrazone(3-fluorophenyl)benzothiazole derivative 38 exhibited remarkable activity against pancreatic adenocarcinoma (Capan-1, IC₅₀ = 0.6 µM) and non-small cell lung cancer (NCI-H460, IC₅₀ = 0.9 µM). Structure–activity relationship analysis revealed that derivatives 45–52, featuring a methoxy group at position 6 of the benzothiazole ring and either a methoxy or fluorine substituent at position 3 of the phenyl ring, showed consistently strong antiproliferative effects across all tested cell lines (IC₅₀ = 1.3–12.8 µM). Furthermore, compounds bearing N,N-diethylamino or N,N-dimethylamino groups at position 4 of the phenyl ring generally exhibited superior activity compared to those with morpholine or piperidine moieties. However, as this study represents an initial screening, further mechanistic investigations are required to confirm specific anticancer pathways and therapeutic relevance. In addition to their in vitro anticancer properties, the antibacterial activity of the compounds was assessed against both Gram-positive and Gram-negative bacteria. Notably, compound 37 demonstrated selective antibacterial activity against Pseudomonas aeruginosa (MIC = 4 µg/mL). Overall, this work highlights the efficiency of a green, mechanochemical approach for synthesizing E-isomer hydrazone-bridged benzothiazoles and underscores their potential as promising scaffolds for the development of potent antiproliferative agents. Full article

Biopurification systems are designed for the treatment of pesticide-containing agricultural wastewater; their biologically active matrix, the biomixture, can be modified to enhance the pesticide removal capacity. Two approaches, fungal bioaugmentation with Trametes versicolor and amendment with biochar, were applied for the potential improvement of biomixtures’ capacity to remediate myclobutanil-contaminated wastewater. The conventional biomixture (B) and its modifications, either bioaugmented with Trametes versicolor (biomixture BT) or supplemented with pineapple biochar (5% v/v) (biomixture BB), were spiked with myclobutanil at a very high concentration (10,000 mg/kg) to simulate extreme on-farm events such as the disposal or leakage of commercial formulations. The dissipation followed a bi-phasic behavior in every case. Both modifications of the conventional biomixture increased the dissipation rates, resulting in estimated DT₅₀ values of 61.9 (BB) and >90 days (BT) compared to biomixture B (DT₅₀ = 474 days). The assessment of biomixtures’ detoxification was carried out with two different bioindicators: a seed germination test in Lactuca sativa and an algal growth inhibition test. Some degree of detoxification was achieved for all biomixtures in both indicators, with the exception of the biochar-containing biomixture, which, despite showing the fastest myclobutanil dissipation, was unable to maintain a steady detoxification trend towards the algae over the course of the treatment, probably due to biochar adverse effects. This approach seems promising for removing persistent myclobutanil from agricultural wastewater and demonstrates the dissipation capacity of biomixtures at extremely high pesticide concentrations likely to take place at an on-farm level. Full article