A composite catalytic system composed of choline chloride, p-chlorophenol, and zinc acetate was developed for the efficient glycolysis of waste polyethylene terephthalate (PET). Under optimal conditions (185°C, 4 h, 2.5 wt% catalyst), PET was depolymerized into high-purity bis(2-hydroxyethyl) terephthalate (BHET) with a yield of 96.3%. The catalyst structure was characterized by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance. Key reaction parameters, such as temperature, ethylene glycol/PET ratio, and catalyst loading, were optimized. The obtained BHET was repolymerized by way of melt polycondensation to produce regenerated PET, which exhibited thermal and structural properties comparable with commercial PET, as confirmed by thermogravimetric analysis, differential scanning calorimetry, FTIR, and nuclear magnetic resonance. The catalyst demonstrated excellent reusability, maintaining over 82% BHET yield after six cycles. This study proposes a sustainable, highly efficient, and fully recyclable strategy for closed-loop PET recycling. Specifically, by harnessing a synergistic Lewis–Brønsted acid system, the strategy demonstrates outstanding scalability and thus holds considerable promise for near-term industrial application.

Incorporating industrial by-products into concrete reduces the environmental impact ofcement production. This study evaluates sustainable ternary concrete mixes containing 10% fly ash, varying silica fume levels (0%, 6%, 12%, 18%, 24%), and 100% manufactured sand as fine aggregate to identify the optimal mix for enhanced mechanical and microstructural properties using scanning electron microscopy (SEM),energy-dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), and machine learning (ML) assessment were done to streamline the experimental process. Compressive, split tensile, and flexural strengths, as well as ultrasonic pulse velocity, were measured at 7, 28, and 90days. The mix with 10% fly ash, 12% silica fume, and 100% manufactured sand demonstrated the highest performance, with compressive strength increases of 18.61%, 16.85%, and 19.83% at each interval. Microstructural analysis revealed a dense C-S-H gel and uniform matrix, indicating improved hydrationand reduced porosity. Machine learning models (LASSO, Random Forest, Gradient Boosting, XGBoost, AdaBoost, and ANN) were applied to predict compressive strengthand to minimise the number of experimental trials. Gradient Boosting achieved the mostaccurate predictions, with an R2 of 0.9929 and minimal error, even with limited data. Both laboratory and machine-learning results confirm that concrete with 10% fly ash, 12% silica fume, and 100% manufactured sand provides a durable, high-performance solution for structural applications.

1,4-Disubstituted 1,2,3-triazoles are readily obtained by copper(I)-catalyzed azide–alkyne 1,3-dipolar cycloaddition (CuAAC)—the most widespread illustration of click chemistry to date. 1,2,3-Triazoles form a vast and easily accessible library of precursors for synthesizing 1,2,3-triazolium ionic liquids (TILs). A series of four 1,3,4-trisubstituted TILs with N-1-n-octyl, N-3-methyl and different C-4 substituents (i.e., aromatic, aliphatic, PEGylated and perfluorinated groups) is synthesized in two steps involving: (i) CuAAC to generate 1,2,3-triazole precursors and (ii) N-alkylation of the 1,2,3-triazole groups with methyl iodide to afford the corresponding 1,2,3-triazolium salts with iodide counter-anions. A thorough investigation of the correlations between structure and properties is carried out using NMR spectroscopy, high-resolution mass spectrometry, differential scanning calorimetry, thermogravimetric analysis and broadband dielectric spectroscopy. The PEGylated TIL has also undergone ion metathesis to produce the TIL analogue with a bis(trifluoromethylsulfonyl)imide counter-anion. Of all the synthesized TILs, this derivative exhibits the lowest glass transition temperature (Tg = −76 °C), the highest thermal stability (Td10 = 345 °C) and the greatest ionic conductivity (σDC = 6.5 × 10−4 S cm−1 at 30 °C under anhydrous conditions).

Nowadays, steel has become an important part of our life due to its extensive applications in automotive, household appliances, business machine and heavy construction such as marine and chemical industries. Mild steel is selected for construction because of its mechanical properties and machine-ability at a low price, while at the same time; they have to be resisted against corrosion phenomena. Nano TiO2 can be used for high lubrication‚ high conductivity‚ and high adsorption rate as well as catalytic performance‚ chemical industry‚ aerospace, and other fields. Characterization of this TiO2 are made by X-ray diffraction, Particle size analysis, Scanning electron microscopy, Energy dispersive X-ray spectroscopy, Thermo gravimetric and differential thermal analysis techniques.

A study was conducted to examine the effects of graphene nanoplatelets (GNPs) on the thermal characteristics of polymer nanocomposites, which are extensively utilised in packaging, biomedicine, and microelectronics. Following ASTM guidelines, samples of GNPs and epoxy were made by shear mixing and solution compounding. Thermo Gravimetric Analyzer (TGA) and Differential Scanning Calorimetry (DSC) were used to examine the samples' thermal stability and glass transition temperature. The results showed that weight retention improved with increasing graphene content, while the addition of GNPs considerably improved thermal properties. As the GNP content increased from 20% to 30%, the glass transition temperature (Tg) climbed from 50°C to 53°C. This study provides important information for material developers by highlighting the possibility for enhanced thermal performance of graphene-dispersed polymer nanocomposites.

Using montmorillonite (MMT) as raw material, Fe3O4 nanoparticles were loaded on the surface of MMT by a solvothermal method to prepare magnetic montmorillonite (M-MMT). The MMT and M-MMT were functionalized with quaternized chitosan (QC) to obtain nanoparticle (NP) demulsifiers of MMT-QC and M-MMT-QC, respectively. The chemical composition and surface properties of the modified montmorillonite nanoparticles were characterized with scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, zeta potentiometer, and vibrating sample magnetometer, which confirmed the successful preparation of the NP demulsifiers. The demulsification performance of the NP demulsifiers for crude oil-in-water emulsion was evaluated by using bottle tests. The effects of demulsification time, pH, demulsifier dosage, and temperature on the demulsification efficiency were investigated. Results showed that under the condition of 25 °C, 1000 mg/L dosage, and pH 6, the demulsification efficiency of MMT-QC and M-MMT-QC was 98.00% and 98.82%, respectively. In addition, the magnetic NP demulsifier of M-MMT-QC has good recycling performance, with no significant decrease in demulsification efficiency within eight cycles. The demulsification mechanism was revealed and proposed. It is believed that the QC-modified magnetic nanoparticles can firmly combine with the protective film through electrostatic attraction and hydrogen bonds. Under stirring or oscillating conditions, the nanoparticles acquire sufficient kinetic energy to destroy the protective film at the oil-water interface, thereby promoting the oil droplet coalescence and enabling fast oil-water separation at room temperature.

Reliable quantification of the chemical composition of graphene-related 2D materials (GR2M) as powders and liquid suspensions is a challenging task. Analytical methods such as X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICP-MS), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) are recommended by standardization bodies. The specific parameters to be measured are also defined, e.g., the oxygen-to-carbon (O/C) atomic ratio, the trace metal impurities, or the functional groups. In this contribution, for the first time, results of a systematic study on the capability of energy-dispersive X-ray spectroscopy (EDS) at a scanning electron microscope (SEM) to reliably quantify the O/C ratio and impurities remained from the synthesis of selected GR2M are reported. The robustness of SEM/EDS analysis is verified for various measurement conditions (different excitations and EDS detectors) and the validity of the results is tested by comparison to the established XPS analysis. Moreover, an ionic liquid is used as a reference material for the quantification of the light elements such as C, N, O and F. The study clearly demonstrates the reliability of the fast and widely available SEM/EDS as a standard method for the quantification of the elemental composition of GR2M and generally of light materials.

The influence of phosphoric acid (H3PO4) and sodium hydroxide (NaOH) impregnation on the pyrolysis and CO2 gasification behavior of dairy manure was evaluated using thermogravimetric analysis (TGA), with kinetic parameters assessed through iso-conversional kinetic analysis (Frieman method). H3PO4 pretreatment altered early decomposition by partially removing hemicellulose and promoting the formation of thermally stable, condensed char structures. The resulting chars exhibited reduced CO2 reactivity, as evidenced by higher gasification temperatures, lower syngas yields, and elevated activation energies, indicating hindered CO2 diffusion and slower Boudouard reaction kinetics. In contrast, NaOH pretreatment caused only minor changes in both pyrolysis and gasification behavior. A slight reduction in pyrolysis activation energy suggested Na+ catalyzed bond-cleavage reactions; however, this effect did not enhance CO2 gasification reactivity. Chars produced from NaOH-treated manure exhibited slightly higher activation energies during CO2 gasification and syngas yields, which remained close to or slightly above those of raw manure, attributed to complex mineral interactions that diminish the catalytic influence of sodium. Overall, these findings clarify how acid and base chemical pretreatments govern char evolution and carbon-CO2 reactivity, providing a foundation for optimizing pretreatment strategies and reactor conditions for manure conversion in CO2-based pyrolysis and gasification systems.

Cement stabilisation efficacy in tropical coastal regions is critically compromised by high soil salinity and temperatures, yet the underlying synergistic mechanisms remain insufficiently characterised. This study quantitatively investigated the evolution of unconfined compressive strength (qu) and microstructural alterations in cement-stabilised silt under varying pore-water salinities (S0 = 0%–4%) and curing temperatures (5°C, 25°C, 45°C). Mercury intrusion porosimetry revealed that increasing salinity from 0% to 4% reduced micropore porosity by 17.8%–19.4% and increased macropore porosity by 44.9%–46.2% under elevated temperatures, reducing water-retention capacity. Scanning electron microscopy and thermogravimetric analysis indicated that elevated salinity and temperature synergistically enhanced ettringite (AFt) formation and drove a morphological transition, inducing microcracking and pore expansion. Consequently, qu exhibited linear degradation with increasing salinity and temperature. Crucially, high-salinity samples (S0 ≥ 3%) cured at 45°C suffered structural disintegration on immersion, causing a complete loss of strength. This study reveals that the expansive behaviour of AFt crystals induced by salinity–temperature synergy, combined with their physical deterioration of the microstructure driven by osmotic pressure upon water immersion, constitutes the primary mechanism for strength degradation in cement-stabilised silt. These findings reveal appreciable engineering implications for coastal cement stabilisation projects, necessitating durability assessments explicitly accounting for coupled salinity-thermal-wetting conditions.

The development of edible films based on natural biopolymers, such as carrageenan, represents an effort to create environmentally friendly food packaging. The objective of this study was to develop a carrageenan-based edible film with the incorporation of High Internal Phase Emulsion (HIPE), which has been stabilized through ultrasonication with a view to enhancing the stability and functional properties of the film. The HIPE formulation employed alginate and soy protein isolate (SPI) as natural stabilizers, with soybean oil as the internal phase. The effects of sonication time (0–10 minutes) on the resulting droplet size and stability were investigated, and it was determined that 7 minutes was the optimal duration for achieving the best results. This condition was found to result in HIPE with high storage and centrifugal stability. The incorporation of HIPE into carrageenan matrix resulted in an increased film thickness, decreased water content and solubility, and increased the water contact angle, indicating improved moisture barrier properties. Mechanically, the increasing HIPE concentration reduced tensile strength, yet increased elongation at break, rendering the film more flexible. Scanning Electron Microscopy (SEM) analysis demonstrated homogeneous globule distribution, whilst FTIR confirmed the presence of hydrogen, electrostatic, and hydrophobic interactions between the components. Thermogravimetric Analysis (TGA) results indicated enhanced thermal stability, with an observed increase in antioxidant activity up to 68% at the optimum HIPE concentration. The findings of this study demonstrate that the incorporation of ultrasonically stabilized HIPE leads to a notable enhancement of carrageenan films, enhancing their potential as safer, sustainable food packaging.

Novel bioactive composite films based on polyvinyl alcohol (PVA) reinforced with walnut shell powder (WSP) and medicinal plant additives – Lawsonia inermis, Nepeta cataria, and Artemisia vulgaris – were developed using a solution casting method for potential biomedical applications. WSP, a lignocellulosic agricultural waste, was employed as a sustainable reinforcing filler, while the herbal additives were incorporated to impart antimicrobial and wound-healing properties. The structural, morphological, chemical, and thermal characteristics of the composite films were investigated using field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). XRD analysis revealed the semi-crystalline nature of PVA, with reduced crystallinity upon filler incorporation due to strong intermolecular interactions. FTIR confirmed effective hydrogen bonding between PVA and the bio-fillers, while thermal analyses demonstrated enhanced thermal stability of the composites. Morphological studies showed smooth to porous surface features depending on the herbal additive used. Antibacterial evaluation against Escherichia coli demonstrated significant inhibition, with the Lawsonia inermis-based composite exhibiting the highest antibacterial activity. Biocompatibility assessment using Vigna radiata seed germination indicated low cytotoxicity and favorable biological interaction, particularly for the Lawsonia inermis formulation. The synergistic integration of WSP and herbal additives within the PVA matrix resulted in multifunctional, sustainable, and biocompatible films, highlighting their strong potential for wound healing, drug delivery, and other biomedical applications.

Nickel-supported catalysts over SiO2-CeO2 mixed oxides were investigated as catalysts for syngas production via dry reforming of methane. SiO2-CeO2 supports were optimized by varying the preparation method and ceria loading with the aim of stabilizing nickel nanoparticles, enhancing the catalytic performance, and improving the resistance to coke formation under high-temperature reforming conditions. To investigate the effect of support composition, SiO2-CeO2 mixed oxides with ceria contents ranging from 5 to 30 wt% were prepared using two synthesis routes: sol–gel and wetness impregnation methods. A nickel loading of 5 wt% was deposited on the resulting supports. The catalysts were characterized by XRD, N2 physisorption, temperature-programmed reduction (TPR), and Raman spectroscopy. Catalytic activity tests were carried out over reduced catalysts in an H2-He stream at 750 °C, using a feed mixture containing 15 vol% CH4 and 15 vol% CO2 in He. The effect of temperature on catalytic performance was evaluated in the range of 450–750 °C. Thermogravimetric, XRD and Raman analyses of spent catalysts were used to assess carbon deposition and the nature of crystalline phases. The results highlight the role of CeO2 content and preparation method in determining nickel dispersion, reducibility, catalytic performance in DRM, and coke resistance.

Insight into effects of torrefaction on biomass: Chemical composition, pyrolysis behavior and products distribution.

The effects of storage time on the characteristics of starch in spicy strips were investigated. Techniques including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) were employed to analyze the gelatinization properties, thermal characteristics, crystal structure, moisture distribution, and quality changes of spicy strips under different storage periods (0, 60, 120, and 180 days). The results demonstrated that prolonged storage led to a significant decrease in peak viscosity and an increase in setback value, indicating enhanced starch retrogradation. DSC analysis revealed a continuous increase in enthalpy change (ΔH), confirming the formation of more ordered double-helix structures over time. TGA revealed a shift in thermal degradation profiles, indicating changes in component interactions and moisture-binding capacity over storage. XRD patterns showed a clear transition from A-type to V-type crystals and finally to an amorphous state after 180 days. Consequently, solubility, swelling power, and amylose leaching were markedly inhibited, while the retrogradation rate of amylopectin became dominant during long-term storage. These findings provide insights into starch retrogradation mechanisms in complex snack matrices and offer guidance on mitigating quality deterioration during the shelf life of spicy strips.

This study presents a comprehensive physicochemical and mineralogical characterization of Erusu clay from Ondo State, Nigeria, with the aim of evaluating its suitability for industrial applications. Analytical techniques employed include X-ray Fluorescence (XRF), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermal Gravimetric and Differential Thermal Analysis (TGA/DTA), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS), and standard plasticity and mechanical tests. The XRF results revealed that silica (SiO₂) and alumina (Al₂O₃) are the predominant oxides, with mean values of 54.8% and 24.5%, respectively, yielding a SiO₂/Al₂O₃ ratio of 1.89, typical of kaolinitic clays. XRD and FTIR analyses confirmed kaolinite (62.3%) as the dominant mineral phase, with quartz, illite, and hematite as accessory minerals. Thermal analysis indicated a total weight loss of 8.2%, with dehydroxylation occurring at approximately 525°C, suggesting good thermal stability. The clay exhibited medium plasticity (PI = 19.6%), low swelling (8.3%), and satisfactory mechanical properties, including green and dry compressive strengths of 118 kN/m² and 410 kN/m², respectively. Its refractoriness, ranging between 1670–1700°C (Cone 32–33), classifies it as a high-refractory clay. The integrated results indicate that Erusu clay possesses favourable structural, thermal, and mechanical characteristics suitable for refractory linings, foundry moulds, and ceramic applications. This study contributes to the valorization of indigenous raw materials for sustainable industrial development in Nigeria.

ABSTRACT Phase change materials (PCMs) are extensively explored for thermal energy storage (TES) applications. While paraffin wax is the most widely studied organic PCM, non‐paraffinic bio‐based fatty acids offer a more sustainable alternative. This study systematically evaluates seven palm fatty acids: caprylic, capric, lauric, myristic, palmitic, stearic, and oleic acids, focusing on thermal stability, reliability, and metal compatibility, compared with paraffin wax. In addition to standard thermal characterization, a heat absorption‐release test was performed to assess heat storage performance. PCM properties were analyzed before and after two thermal reliability assessments: thermal treatment (up to 700 h) and thermal cycling (up to 350 cycles). Differential scanning calorimetry (DSC) determined phase change temperature, latent heat, and specific heat capacity ( C p ), while thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) assessed thermal and chemical stability. The palm fatty acids exhibited slight variations in phase change temperature (0.03°C–3.6°C) and moderate melting latent heat reductions (−3.2% to −6.2% after thermal treatment, −7.5% to −13.8% after thermal cycling), comparable to paraffin wax (0.04°C–1.32°C, −7.0%, −10.3%, respectively). Similar to paraffin wax, changes in C p , heat storage performance, TGA, and FTIR results further confirmed the thermal reliability of palm fatty acids. Twelve‐week corrosion tests showed decreasing corrosion rates with time and confirmed the compatibility of all tested PCMs with stainless steel, aluminum, copper, and brass, with most corrosion rates remaining below the critical threshold for long‐term use. Overall, palm fatty acids demonstrate high thermal reliability, stability, and metal compatibility comparable to paraffin wax, establishing them as sustainable bio‐based PCMs for long‐term TES applications.

Phenol-assisted depolymerization of Acacia mangium tannin for strong and fast-curing biomass-based phenolic resins.

A fungal lectin that reinforces the cell wall to enhance fermentation.

Gas-solid reaction models of Sr(CuxFe1-x-yTiy)O3-δ perovskite-based oxygen carriers for chemical looping combustion.

Ethanol dehydration is a common step in both scaffold manufacturing and tissue processing, yet the influence of ethanol on collagen is not well understood. This study examined the effects of dehydration, via ethanol treatment and air drying, on collagen structure, behavior, mechanics, and rehydration capacity. Multiple material characterization methods were used including Fourier Transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy, thermogravimetric analysis, small/medium angle x-ray scattering, volumetric swelling analysis, and tensile testing. Ethanol dehydration removed bulk water from scaffolds, making them stronger and stiffer, but also showed loss of molecular water. This molecular water appears to act as a collagen stabilizer, resulting in less thermally stable scaffolds. The loss of molecular water is also evident in the molecular d-spacing. Secondary structure of scaffolds was also altered by ethanol, resulting in significantly enhanced rehydration capacity. Bulk water, both before and after rehydration, largely determined mechanical properties, which did not correlate with other structural measures such as FTIR. While rehydration largely returned collagen spacing to pre-ethanol treated state, structural alterations seen in FTIR cannot be recovered. These results have implications for not only collagen scaffolds, but in many tissue engineering and processing applications.