Differential Thermal Analysis Research Articles

Thermoanalytical and Kinetic Studies for the Thermal Stability of Emerging Pharmaceutical Pollutants Under Different Heating Rates

Emerging pharmaceutical pollutants like ciprofloxacin (CIP) and ibuprofen (IBU) are frequently detected in aquatic environments, posing risks to ecosystems and human health. Since pollutants rarely exist alone in the environment, understanding the thermal stability and degradation kinetics of these compounds, especially in mixtures, is crucial for developing effective removal strategies. This study therefore investigates the thermal stability and degradation kinetics of CIP and IBU, under different heating rates. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were employed to examine the thermal behavior of these compounds individually and in mixture (CIP + IBU) at heating rates of 10, 20, and 30 °C/min. The kinetics of thermal degradation were analyzed using both model-fitting (Coats–Redfern (CR)) and model-free (Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and Friedman (FR)) methods. The results showed distinct degradation patterns, with CIP decomposing between 280 and 550 °C and IBU between 152 and 350 °C, while the mixture exhibited multistep decomposition in the 157–500 °C range. The CR model indicated first-order kinetics as a better fit for the degradation (except for IBU). Furthermore, CIP exhibits higher thermal stability and activation energy compared to IBU, with the KAS model yielding activation energies of 58.09 kJ/mol for CIP, 11.37 kJ/mol for IBU, and 41.09 kJ/mol for CIP + IBU mixture. The CIP + IBU mixture generally showed intermediate thermal properties, suggesting synergistic and antagonistic interactions between the compounds. Thermodynamic parameters (ΔH°, ΔG°, ΔS°) were calculated, revealing non-spontaneous, endothermic processes for all samples (except in the FWO method) with a decrease in molecular disorder and positive ΔG° values across all models and heating rates. The study found that higher heating rates led to less thermodynamically favorable conditions for degradation. These findings provide important information concerning the thermal behavior of these pharmaceutical pollutants, which can inform strategies for their removal from the environment and the development of more effective waste-treatment processes.

Synthesis, Structure, and Properties of Dion–Jacobson Double‐Layered Perovskites A′SmNb2O7 (A′=Rb, K, Na, Li, H)

AbstractDion‐Jacobson‐type layered perovskite compounds A′SmNb2O7 (A′=Rb, K, Na, Li, H) were synthesized using solid‐state and ion‐exchange methods. While the parent solid‐state product RbSmNb2O7, has previously been studied, the ion‐exchanged compounds were obtained and studied for the first time. The phase and chemical purity of the compounds were confirmed by X‐ray diffraction (XRD) and energy‐dispersive X‐ray spectroscopy (EDX). The crystal structures of RbSmNb2O7 (I2 cm, a=0.54356(1) nm, b=0.53935(1) nm, c=2.1891(5) nm), KSmNb2O7 (I2 cm, a=0.53660(7) nm, b=0.54481(6) nm, c=2.1527(1) nm) and LiSmNb2O7 (B2 cm, a=0.54546(4) nm, b=0.53567(4) nm, c=2.04582(5) nm) were refined using the Rietveld method. Polyhedral distortions in these structures have been studied in detail. The thermal behavior of the compounds has been determined using differential thermal analysis (DTA), revealing that A′=Na, Li and H compounds are metastable hydrates, while A′=Rb and K compounds are stable. The optical band gap, valence band edge, and conduction band edge potentials of the compounds obtained were calculated using diffuse reflection spectroscopy data. A photocatalytic experiment was performed on the degradation of methylene blue under ultraviolet light. All of the samples obtained showed some asctivity in the reaction of dye photooxidation.

Solubility and magnetic properties of Ag−Co−Si alloy synthesized by mechanical alloying and annealing

AbstractThis present work concerns the effect of ternary addition of non‐metallic and diamagnetic silicon on the metastable solubility of the immiscible silver‐cobalt system during the course of ball milling, annealing of the ball milled samples and the corresponding magnetic properties. It should be noted that silicon has a smaller goldsmidt radius (111 pm) than silver (144 pm) and silicon+4 has more valence electrons than silver+1. Keeping the objectives of the current study in mind, silicon may thus be considered as an option for ternary addition, in contrast to metallic components. An attempt has been made to examine the phase changes that occurred in the 50 silver‐40 cobalt‐10 silicon (atom percent) system during ball milling and the subsequent isothermal annealing of the ball milled product. Phase evolution during mechanical alloying and isothermal annealing is identified by means of x‐ray diffraction, differential thermal analysis, high resolution transmission electron microscopy and magnetic measurements. The addition of silicon facilitates cobalt‘s formation of a metastable alloy with copper after 50 hours of ball milling. Annealing significantly improves the magnetic characteristics of materials that have been ball milled; the optimal combination of magnetic properties was obtained after an hour of annealing at 550 °C.

Chemical and Thermal Changes in Mg3Si2O5 (OH)4 Polymorph Minerals and Importance as an Industrial Material

Serpentine (Mg3Si2O5(OH)4), like quartz, dolomite and magnesite minerals, is a versatile mineral group characterized by silica and magnesium silicate contents with multiple polymorphic phases. Among the phases composed of antigorite, lizardite, and chrysotile, lizardite and chrysotile are the most prevalent phases in the serpentinites studied here. The formation process of serpentinites, which arise from the hydrothermal alteration of peridotites, influences the ratio of light rare earth elements (LREE) to heavy rare earth elements (HREE). In serpentinites, the ratio of light rare earth elements (LREE)/heavy rare earth elements (HREE) provides insights into formation conditions, geochemical evolution, and magmatic processes. The depletion of REE compositions in serpentinites indicates high melting extraction for fore-arc/mantle wedge serpentinites. The studied serpentinites show a depletion in REE concentrations compared to chondrite values, with HREE exhibiting a lesser degree of depletion compared to LREE. The high ΣLREE/ΣHREE ratios of the samples are between 0.16 and 4 ppm. While Ce shows a strong negative anomaly (0.1–12), Eu shows a weak positive anomaly (0.1–0.3). This indicates that fluid interacts significantly with rock during serpentinization, and highly incompatible elements (HIEs) gradually become involved in the serpentinization process. While high REE concentrations indicate mantle wedge serpentinites, REE levels are lower in mid-ocean ridge serpentinites. The enrichment of LREE in the analyzed samples reflects melt/rock interaction with depleted mantle and is consistent with rock–water interaction during serpentinization. The gradual increase in highly incompatible elements (HIEs) suggests that they result from fluid integration into the system and a subduction process. The large differential thermal analysis (DTA) peak at 810–830 °C is an important sign of dehydration, transformation reactions and thermal decomposition, and is compatible with H2O phyllosilicates in the mineral structure losing water at this temperature. In SEM images, chrysotile, which has a fibrous structure, and lizardite, which has a flat appearance, transform into talc as a result of dehydration with increasing temperature. Therefore, the sudden temperature drop observed in DTA graphs is an indicator of crystal form transformation and CO2 loss. In this study, the mineralogical and structural properties and the formation of serpentinites were examined for the first time using thermo-gravimetric analysis methods. In addition, the mineralogical and physical properties of serpentinites can be recommended for industrial use as additives in polymers or in the adsorption of organic pollutants. As a result, the high refractory nature of examined serpentine suggests that it is well-suited for applications involving high temperatures. This includes industries such as metallurgy and steel production, glass manufacturing, ceramic production, and the chemical industry.

Exploring the influence of metal oxides on the pyrolytic behavior and decomposition mechanism of the green gas generating agent 5-Aminotetrazole

5-Aminotetrazole (5AT) is widely used as a green gas-generating agent in fire extinguishers, but it exhibits low combustion stability. To enhance its combustion rate and modify gas production performance, this study investigated the catalytic effects of adding different metal oxides (Bi2O3, PbO, TiO2, and CoO) on its pyrolysis process and decomposition mechanism. The pyrolysis behavior and pyrolysis products of 5AT were studied by simultaneous thermal analyzer (thermogravimetry - differential thermal analysis, TG-DTA) and TG-FTIR/MS (mass spectrometry and fourier transform infrared spectroscopy) hyphenated instrument. Isoconversional methods were used to calculated kinetic parameters, and reaction mechanism was also speculated by combining the experimental and calculational results. The experimental results indicated that Bi2O3, PbO, TiO2 and CoO have minimal impact on the ring opening reaction process of 5AT, but they catalyzed the polymer decomposition process of 5AT, especially CoO. Consequently, the addition of metal oxides as catalysts to 5AT holds significant potential for improving its thermal safety and enhancing its suitability as a solid propellant gas generator.

Thermal analysis of mortar based on crushed dune sand

This study investigates the thermal decomposition behavior of mortars formulated using crushed dune sand and thixotropic polyester resin. Thermal analysis techniques, including Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA), and Gravimetric Thermal Analysis (GTA), were employed to characterize the thermal transitions, decomposition stages, and stability of these mortars. Results indicate that crushed dune sand maintains consistent glass transition (Tg) and crystallization temperatures (Tc) when integrated into the mortar matrix, highlighting its thermal stability. However, the melting point (Tm) varies due to the presence of the resin, which significantly influences the composite’s thermal behavior. Decomposition analysis reveals two major weight loss stages: water evaporation between 200°C to 400°C and organic decomposition of the resin between 700°C to 800°C, with minimal weight change beyond 800°C, indicating thermal stability. The DTA results exhibit distinct endothermic reactions related to dehydration and dehydroxylation, along with a pronounced exothermic peak around 400°C, signifying resin decomposition. Elemental analysis confirms that the crushed dune sand is predominantly silica with minimal impurities, making it suitable for construction applications. This research contributes to a deeper understanding of the thermal behavior of polymer-modified mortars, with implications for enhancing thermal and mechanical properties in construction materials.

Atypical phase transition, twinning and ferroelastic domain structure in bis(ethylenediammonium) tetrabromozincate(II) bromide, [NH3(CH2)2NH3]2[ZnBr4]Br2.

Single-crystal growth, differential thermal analysis (DTA), derivative thermogravimetry (DTG), differential scanning calorimetry (DSC), X-ray structural studies and polarized microscopy observations of bis(ethylenediammonium) tetrabromozincate(II) bromide [NH3(CH2)2NH3]2[ZnBr4]Br2 are presented. A reversible phase transition is described. At room temperature, the complex crystallizes in the monoclinic system. In some cases, the single crystals are twinned into two or more large domains of ferroelastic type with domain walls in the (100) crystallographic plane. DTA and DTG measurements show chemical stability of the crystal up to ∼538 K. In the DSC studies, a reversible isostructural phase transition was revealed at ∼526/522 K on heating/cooling run, respectively. Optical observation on the heating run reveals that at the phase transition the plane of twinning (domain wall) does not disappear and additionally the appearance of a new domain structure of ferroelastic type with domain walls in the planes (101), (101), (100) and (001) is observed. The domain structure pattern is preserved after cooling to the room-temperature phase and the symmetry of this phase is unchanged.

Temperature-Dependent Compressive Strength Modeling of Geopolymer Blocks Utilizing Glass Powder and Steel Slag

This article investigates the development of geopolymers as a modern, environmentally sustainable binder with ceramic-like properties, offering exceptional thermal and fire-resistant characteristics. The study primarily utilized fly ash (FA) in combination with glass powder (GP) and steel slag (SS). The SS content varied between 30% and 40%, while the molarity of NaOH was set at 10M, 12M, and 14M. Based on these variables, a total of 18 mixes incorporating GP and SS were formulated. The samples were subjected to elevated temperatures of 200 °C, 400 °C, 600 °C, and 800 °C, after which their compressive strength was measured. To better understand the material formation, scanning electron microscopy and energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetry differential thermal analysis analyses were conducted. The study aimed to examine the influence of oxide ratios (Na/Si, Si/Al, H2O/Na2O, and Na/Al) on compressive strength at elevated temperatures. Additionally, the research sought to develop a predictive model, elucidating the relationship between these oxide ratios and compressive strength of geopolymers. To achieve this, ten machine learning techniques were applied, revealing the complex connection between oxide ratios and the strength properties of geopolymers. The support vector regressor (SVR) model outperformed other regression and boosting models, achieving a high coefficient of determination (R2) value of 0.95, indicating superior predictive accuracy. The reduced error levels and high R2 values highlighted the enhanced performance of the SVR model. A sensitivity analysis was done to understand the contributions of each parameter to the outcome predictions further. Employing machine learning techniques to forecast compressive strength of geopolymer blocks under various elevated temperature conditions improves predictive accuracy and optimizes resource utilization, leading to significant time savings.

OPTIMIZATION OF HEAT TREATMENT REGIME FOR A NEW BIODEGRADABLE Mg-Zr-Nd ALLOY WITH ENHANCED MECHANICAL PROPERTIES

Purpose. To develop a rational heat treatment regime for a new biodegradable magnesium alloy of the Mg-Zr-Nd system, to ensure enhanced mechanical properties throughout the entire treatment period. Research methods. Differential thermal analysis (DTA) was used to determine phase transformation temperatures. Microstructure analysis was conducted using optical microscopy (“Neophot 32” and “OLYMPUS IX 70”) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SELMI RЕМ-106I). Mechanical properties were determined using an INSTRON 2801 testing machine. The influence of cooling rate on microstructure and properties was studied using ProCAST simulation software. Heat treatment was carried out in a Bellevue type shaft furnace and a PAP-4M furnace. X-ray analysis was used to detect internal defects in samples. Results. A new heat treatment regime was developed for the biodegradable Mg-3.15Nd-1.25Zr-0.6Zn (wt%) alloy. Using differential thermal analysis and microstructure studies at various quenching temperatures, the optimal quenching temperature was established at 560 °C. Empirical relationships describing the influence of heat treatment parameters on the alloy's microstructure were calculated. The new heat treatment regime (quenching from 560 °C for 8 hours, air cooling + aging at 200 °C for 16 hours) resulted in improved mechanical properties (UTS = 276–282 MPa, δ = 5.2–5.8%) compared to the standard T6 regime. Scientific novelty. For the first time, a comprehensive study of the influence of heat treatment parameters on the structure and properties of a new Mg-3.15Nd-1.25Zr-0.6Zn (wt%) alloy with increased content of alloying elements was conducted. New dependencies describing the influence of quenching temperature on the alloy's grain size were established. Practical value. A new heat treatment regime for the biodegradable magnesium alloy was developed, which ensures complete dissolution of the pseudoeutectic phase and formation of strengthening phases, resulting in improved mechanical properties compared to the standard alloy Mg-2.5Nd-0.4Zn-0.5Zr (wt%) and the standard T6 regime.

Experimental evaluation and simulation of myoblast cell alignment on the UV-irradiated liquid crystalline elastomers as a versatile tissue-engineered Scaffolding material

Efforts to develop versatile tissue-engineered scaffolds mimicking the functions of extracellular matrices (ECMs) have led to the emergence of liquid crystalline elastomers (LCEs) as promising materials. Here, thiol-acrylate-based LCEs forming a nematic phase upon UV irradiation were synthesized, and their biological compatibility was evaluated using C2C12 myoblast cells. Prior to UV exposure, some characteristics, e.g., phase transition temperature (TNI), order parameter, and reaction time, of the as-synthesized LCEs are characterized for property optimization. Fourier-transform infrared spectroscopy revealed that thiol-acrylate Michael addition polymerization was successful, judged by the disappearance of the characteristic peaks of thiol and acrylate groups. Differential scanning calorimetry thermograms and dynamic mechanical thermal analysis curves showed TNI values at ca. 49 °C, at which point the nematic phase is the dominant morphology. Moreover, the cross-linking density, the fixing, and the recovery ratios for the sample with optimal properties (i.e., LCE3) were determined to be 10.3 mol/cm3, 97.2 % and 91 %, respectively. Assessment of mesomorphism and roughness demonstrated the suitability of LCE3 for cell culture. Subsequent studies on adhesion, viability, differentiation, and proliferation of cultured myoblast cells, coupled with particle image velocimetry simulation, highlighted the potential of UV-irradiated LCE3 as a promising scaffold material for inducing surface morphology-induced cellular alignment and interactions.

Liquid-phase synthesis of a Li3PS4 solid electrolyte using ethyl isobutyrate as a synthetic medium

A β-Li3PS4 solid electrolyte was prepared via liquid-phase synthesis using ethyl isobutyrate as a synthetic medium. The precursor and solid electrolyte structures were characterized using thermogravimetry–differential thermal analysis and X-ray diffraction techniques. The dielectric relaxation analysis showed two relaxation regions, which revealed a bulk and grain boundary ionic migration process. At a temperature lower than 90°C, the frequency dependence of the dielectric constant of the prepared sample was different from that of glassy Li3PS4, indicating that the motion of the PS4 unit enhances the ionic conductivity of the Li3PS4 solid electrolyte. The ionic conductivities of the cold-pressed and warm-pressed pellets at 25°C were 6.8 × 10−5 Scm−1 and 3.6 × 10−4 Scm−1, respectively.

Synthesis and Properties of a Red Na5Zn2Gd1−x(MoO4)6: xEu3+ Phosphor

Novel Eu3+-doped Na5Zn2Gd(MoO4)6 triple molybdate phosphors were fabricated by the sol-gel method. The structure, morphology, and luminescent properties have been characterized by X-ray diffraction (XRD), thermogravimetric differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), FTIR spectroscopy, and luminescence spectroscopy. The results indicated that the synthesized Na5Zn2Gd1−x(MoO4)6: xEu3+ phosphor consisted of a pure phase with monoclinic structure. Under excitation at 465 nm, the Na5Zn2Gd1−x(MoO4)6: xEu3+ phosphor exhibits an intensive red emission band around 610 nm corresponding to the transition of 5D0→7F2 which is much higher than that 5D0→7F1 at 594 nm, which was appropriate for a blue LED. According to the influence of the synthesis conditions, the phosphors showed the highest emission intensity when the doping concentration of Eu3+ was 25 mol.% and the molar ratio of citric acid to metal ions was 2:1. Na5Zn2Gd0.75(MoO4)6: 0.25 Eu3+ with the color coordinates (x = 0.658, y = 0.341) is a more stable red phosphor for blue-based white LEDs than the commercial Y2O2S: Eu3+ red phosphor (0.48, 0.50) due to its being closer to the NTSC standard values (0.670, 0.330).

Anti-pathogenic and probiotic-friendly effect of benzyloxy pyridine derivative impregnated into bacterial cellulose matrix

Bacterial cellulose (BC) has emerged as a promising biomaterial for biomedical applications due to its unique properties. In this study, firstly, the potential of BC as a carrier material for the originally synthesized benzyloxy pyridine derivative (BeOxP), and also an antimicrobial and probiotic bacteria-friendly (on Lactiplantibacillus plantarum 299v (LP299V®) (DSM 9843)) effect of BC- BeOxP was investigated. The BC- BeOxP composite material was developed using a simple and efficient method, ensuring the uniform dispersion of BeOxP within the BC matrix. Characterization of BeOxP has been carried out with High-Resolution Mass Spectroscopy (HRMS) and Nuclear Magnetic Resonance (NMR). Additionally, BC- BeOxP was characterized by Thermogravimetric analysis (TGA), Differential thermal analysis (DTA), Scanning Electron Microscopy (SEM), Texture analysis, and Fourier-transform infrared spectroscopy (FTIR), confirming the successful integration of BeOxP without compromising the structural integrity of BC. The mechanical properties of the BC- BeOxP composites were also evaluated to ensure their suitability for drug-carrying or food-packaging applications. Antimicrobial activity of the BC- BeOxP was analyzed against Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922 while the probiotic-friendly effect was tested on Lactiplantibacillus plantarum 299v (LP299V®) (DSM 9843). The findings open avenues for further research of BC-based drug carriers or packaging materials for advanced biomedical applications.

Biochar Regulates the Humification of Kitchen Waste and the Effects of the Humic Acid Structure of Products on Black Soil

Kitchen waste is a misplaced resource that is characterized by a high organic matter content, high water content, and a tendency to rot easily. Biochar is a black solid substance produced under high-temperature, anaerobic conditions using agricultural organic wastes as the raw material. It possesses a large specific surface area, a loose and porous structure, and functional groups, which confer high thermal stability and strong adsorption capabilities. However, little is known about how humic products made from biochar affect the composition and structure of soil humus. To solve the above problems, this study carried out a two-year outdoor field experiment by means of element analysis, infrared spectroscopy, and differential thermal analysis (0.4 kg/m2 (W4), 0.8 kg/m2 (W8), 1.2 kg/m2 (W12), 1.6 kg/m2 (W16), and 2.0 kg/m2 (W20)); CK was the blank control (no application). The samples were collected one year and two years after they returned to the field. The results showed that the application of organic materials facilitated the accumulation of soil organic carbon (SOC) and increased the total nitrogen (TN) content. The highest SOC content in the W20 treatment was 12.39 g/kg and 14.67 g/kg in one and two years, respectively. The maximum relative HA content in the W20 treatment was 22.99% one year after returning to the field. The PQ value (the ratio of HA/(fulvic acid (FA) + HA)) for the W20 treatment was 88.21%. The W20 treatment greatly increased the SOC and humus carbon contents. Compared with the CK treatment, all the organic materials applied for one year improved the structure of the humic acid to varying degrees, increased the degree of oxidation, reduced the degree of condensation and thermal stability of the HA in the soil, and gradually simplified the structure of the humic acid; among all the treatments, the W20 treatment had the greatest effect.

Plant-mediated synthesis, characterization, and evaluation of a copper oxide/silicon dioxide nanocomposite by an antimicrobial study

Abstract This study presents an innovative, environmentally friendly method for biosynthesizing copper oxide–silica (Cu2O/SiO2) nanocomposites (CSNCs) utilizing an aqueous leaf extract of Callistemon viminalis (C. viminalis). The goal of this work is to fabricate CSNCs using a less hazardous and sustainable synthesis approach. Copper acetate and sodium metasilicate were used as precursors, whereas the C. viminalis green leaf extract was used as the reducing and stabilizing agent. Analysis of the plant extract using Fourier transform infrared spectroscopy indicated the presence of polyphenolic compounds, primarily phenolic acids, which functioned as both reducing and stabilizing agents in the synthesis of CSNCs. A combination of energy dispersive X-ray spectroscopy and scanning electron microscopy was used to study the formation of spherical copper–silica hybrid nanostructures. Powder X-ray diffraction analysis revealed the successful integration of silica with copper(i) oxide (Cu2O) through the presence of distinct Cu2O peaks and a broad amorphous SiO2 peak at 2θ = 22.77°. The thermal stability of the nanocomposites (NCs) was assessed using thermogravimetric analysis and differential thermal analysis under a nitrogen atmosphere. The biogenic NCs also successfully inhibited pathogenic strains of Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans); however, S. aureus was found to be more susceptible to the biocidal activity of the NCs than P. aeruginosa. These findings suggest that this simple, cost-effective, and eco-friendly method for producing biologically active hybrid nanomaterials holds significant promise for future applications in both biological and materials sciences.

Phase stability of solid solution La1-xRxRh3B (R = Gd, Lu and Sc) compounds with cubic anti-perovskite type structure

We have investigated the solid solution range of single phase La1-xRxRh3B (R = Gd, Lu and Sc) compounds with a cubic anti-perovskite type structure. The behaviors of lattice parameters, hardness, and thermogravimetry–differential thermal analysis (TG-DTA) were also investigated. The cubic anti-perovskite phase exists over the entire composition range x from 0.0 to 1.0 for all La-Gd, La-Lu and La-Sc systems. Both the lattice parameters and the hardness in all La-Gd, La-Lu and La-Sc systems show a linear dependence on the degree of the substitution x of La atom. The results of TG-DTA measurements indicate that oxidation of the compounds in air begins at about 500–600 K. The mixed phases of RBO3, R2O3 and Rh are identified as oxidized products around x = 0.4 to 0.6 composition. The oxidation onset temperature, and weight gains due to the oxidation depend on the degree of substitution x. The behavior of crystallographic and physical/chemical properties in the present compounds La1-xRxRh3B strongly depend on the atomic size of the rare-earth atoms that form the cubic framework.

Effect of Morphology and Concentration of CeO2 Nanoceria on the Thermal Stability of Polyvinyl Alcohol Films

Objective: To determine the thermal stability of polyvinyl alcohol films under different concentrations of CeO2 nanoceria. Method: Cerium Oxide doped polyvinyl alcohol (PVA) nano-composites were synthesized by the traditional solution casting method for various concentrations of nano CeO2 by solution combustion method. The thermal properties of prepared PVA-2.5 wt% CeO2, PVA-7.5 wt% CeO2 , PVA-12.5 wt% CeO2, and PVA-25 wt% CeO2 composite films were elucidated by using techniques such as Differential Scanning Calorimetry, Thermogravimetry analysis and Differential Thermal analysis. Findings: The glass transition temperature of the pure PVA is found to be 114°C, whereas it varies between 110°C-120°C for composite films. The melting temperature of the composite films is the same as that of pure PVA except in the case of 7.5wt% CeO2 and 25wt% CeO2 composites. The reduced melting point of these composites elicits a decrease in crystallinity. A 12.5 wt % and 25 wt% CeO2-PVA nano-composite films exhibit an increase in the final degradation temperature, a high specific heat capacity, low mass loss, and a larger residual weight, indicating their potential applicability in thermal coating and thermal sensing applications. Polyvinyl alcohol (PVA) films are being used routinely as a dielectric layer for electrical applications due to the good physiochemical and dialectic properties of the material. An incorporation of CeO2 nanoceria improves not only the thermal but also the mechanical properties of PVA and extends its application for electrical and optical operation. Here in the present study, different concentrations of CeO2 were incorporated with the PVA and analysed for the thermal properties. The study showed that 12.5 wt % and 25 wt% CeO2-PVA nano-composite enhanced PVA film thermal stability. Keywords: PVA-CeO2 Nanocomposites; Differential Scanning Calorimetry; Thermogravimetry Analysis and Differential Thermal Analysis; Physical properties and thermal properties

Effect of al content on microstructure and corrosion resistance of Zn-Al-Mg alloy

In order to solve the solidification microstructure of Zn-1.7Al-1.1Mg alloy on the surface of steel plate during hot dip plating, the solidification path and microstructure of Zn-1.7Al-1.1Mg alloy were studied by Thermo-Calc thermodynamic software, differential thermal analysis (DSC) and scanning electron microscopy (SEM). The results show that during cooling from melting to room temperature, Zn-1.7Al-1.1Mg alloy begins to precipitate Zn-rich η phase at 386.5 °C, binary eutectic structure consisting of η phase and Mg2Zn11 at 350.0 °C, and ternary eutectic structure consisting of η phase, Al-rich metastable β phase and Mg2Zn11 at 343.4 °C,at 276.7 °C, β phase transforms into stable aluminum-rich α and η phases.

Review about the history of thermal analysis in Hungary

AbstractThis review discusses the development of the Derivatograph in the 1950s and the history of thermal analysis in Hungary. This device was the first commercial simultaneous thermogravimetry and differential thermal analysis (TG/DTA) instrument of the world. It initiated the development of thermal analysis and its application possibilities in a wide range during the second half of the last century. As a result, very strong thermoanalytical schools were established in Hungary, and the first thermoanalytical journal in the world, i.e., the Journal of Thermal Analysis was started in 1969, which is still a leading journal in the field, now under the title of Journal of Thermal Analysis and Calorimetry. In addition, several periodicals and books were published in thermal analysis in Hungary. In the paper, the most important Hungarian thermal analysis-related associations, events, acknowledgements and awards are also mentioned, together with names of major Hungarian researchers in this field. Presently, beside the internationally acknowledged research groups and the JTAC, the flagship of the Hungarian thermal analysis is the Journal of Thermal Analysis and Calorimetry Conference (JTACC) series.

An analysis of the synthesis, crystal structure, optical, spectroscopic, mechanical, self-focusing, and third-order nonlinear optical properties of Kojic acid single crystals

A single, excellent crystal of Kojic acid (KA) was developed utilising the traditional approach of gradual evaporation in a solution-growing procedure. A variety of characterisation techniques were utilised to evaluate the characteristics of the crystals generated. Single crystal x-ray diffraction (SXRD) was utilised to identify the crystal structure. The crystalline arrangement of the KA crystal was confirmed using a powder x-ray diffraction (PXRD) analysis. Experiments with UV–vis spectrometers revealed that the KA crystal has a lower wavelength at which it blocks UV light but has outstanding light transmission throughout the visible spectrum. The KA single crystal has an energy band gap (Eg) of 2.5 eV. The Z-scan method was used to examine the third order susceptibility, nonlinear refraction, and nonlinear absorption coefficient of the synthesised KA crystal. The dielectric characteristics and AC conductivity were examined, with a particular emphasis on their connection to resistance at room temperature. The presence of appreciable levels of kojic acid was confirmed by energy-dispersive spectrometry. The crystal’s thermal behaviour was investigated using differential thermal analysis (DTA) and thermogravimetric (TG) methods. The nucleation parameters and controlled nucleation rate were calculated using normal theoretical research methods.