Thermogravimetric Differential Thermal Analysis Research Articles

The L-proline modified Zr-based MOF (Basu-proline) catalyst for the one‐pot synthesis of dihydropyrano[3,2-c]chromenes

A novel, reusable, and efficient L-proline-modified Zr-based metal–organic framework (Basu-proline) was designed, synthesized, and characterized by Fourier Transform-Infrared spectroscopy (FT-IR), Energy-Dispersive X-ray spectroscopy (EDX), elemental mapping, Field Emission Scanning Electron Microscopy (FE-SEM), X-ray Diffraction analysis (XRD), Thermo-Gravimetric-Differential Thermal Analysis (TGA-DTA), and N2 adsorption–desorption isotherms. Then, its catalytic performance was assessed in the synthesis of dihydropyrano[3,2-c]chromenes via the one-pot, three‐component tandem condensation reaction of 4-hydroxycoumarin, aromatic aldehydes and malononitrile. The Basu-proline catalyst exhibited a better efficiency than some reported protocols regarding higher yields, lower reaction times, and simple separation.

Effects of Nanocellulose Extracted from Pineapple Leaf Fiber Incorporation on the Physico-Chemical and Thermal Properties of Reinforced Epoxy Nanocomposites

The effects of nanocellulose extracted from pineapple leaf fiber on the physico-chemical and thermal properties of epoxy nanocomposite are reported. Nanocellulose was added to the epoxy in different amounts of loadings (0.5, 1.0, 1.5, and 2.0 wt.%) to prepare nanocomposites. The physico-chemical and thermal properties of the nanocellulose reinforced epoxy nanocomposites were investigated. Surface characterization of the nanocomposite was done using scanning electron microscopy (SEM). Functional groups of the nanocomposites were evaluated using fourier transform infrared (FTIR) spectroscopy. Thermal properties of the nanocomposites were investigated using thermogravimetric analyzer (TGA) and differential thermal analyzer (DTA). Experimental results revealed that the 0.5, 1.0, and 1.5 wt.% nanocellulose loadings were homogeneously distributed and well-dispersed in the composite matrix as indicated in the SEM images. However, aggregation was observed in the matrix with 2.0 wt.% nanocellulose loading. Moreover, FTIR spectra revealed that the absorbance of the vibrational mode corresponding to the interaction of nanocellulose and epoxy matrices significantly increases as the nanocellulose loading ratio increased. Furthermore, thermal analysis (TGA/DTA) showed that the incorporation of nanocellulose improved significantly the thermal properties of epoxy nanocomposites.

Optimisation of synthesis parameters for Co-Mo/MgO catalyst yield in MWCNTs production

This study examined the impact of synthesis parameter on Cobalt-Molybdenum supported with magnesium oxide (Co-Mo/MgO) catalyst yield in production of multiwall carbon nanotube (MWCNT). Wet impregnation was used to synthesis the Co-Mo/MgO bimetallic catalyst, while a catalytic chemical vapour deposition reactor (CCVD) was used for the synthesis of carbon nanotubes (CNTs). Factorial and central composite design techniques were used to optimise the catalyst and multi-wall carbon nanotubes (MWCNTs). Thermogravimetric analysis/ Differential thermal analysis (TGA/DTA), selected area (electron) diffraction (SAED), X-Ray diffraction analysis (XRD), and Brunauer–Emmett–Teller (BET) were used to characterise the catalyst and MWCNTs that were produced. The Co-Mo/MgO catalyst had an optimal yield of 93.22%, 247.30 m2/g of specific surface area at 120 °C drying temperature, 16 g of mass support, and a 10-hour drying time. The maximum catalyst yield of 40.62% was obtained at calcination temperature of 500 °C and a holding period of 2 hours. The catalyst with the highest degradation temperature of 398.21 °C was observed at 600 °C, when calcined for 4 hours. It was discovered that the surface area of Co-Mo/MgO catalyst from the BET analysis under ideal conditions varied depending on the holding time. The XRD and SAED revealed the growth of CNTs of concentric graphene pattern with the Co-Mo/MgO catalyst.

Thermogravimetric Assessment and Differential Thermal Analysis of Blended Fuels of Coal, Biomass and Oil Sludge

The coupled combustion of biomass and organic solid wastes including oil sludge has attracted much attention. Although the optimal mixing ratio of different coal types and biomass has been extensively studied, little attention has been paid to oil sludge that has undergone co-combustion. In this study, the combustion characteristics of blended fuel for coal, biomass and oil sludge under different mixing ratios are studied via a thermogravimetric test and differential thermal analysis. Kinetic analysis of tri-fuel is performed using the Flynn–Wall–Ozawa (FWO) and Dolye methods. The results show that the bituminous coal combustion process mainly involves the combustion of fixed carbon (236.0–382.0 °C). Wood pellet combustion (383.0–610.0 °C) has two processes involving the combustion of compound carbon and fixed carbon. Blending wood pellets effectively enhances combustion efficiency. Wood pellets from Korla (KOL) have the most obvious effect on reducing the ignition temperature. The blending combustion of bituminous coal (SC), wood pellets from Hutubi (HTB) and oil sludge (OS) have significant synergistic effects. As the OS mixing ratio increases from 10% to 20% with 45% HTB, Ti and Th decrease from 354.9 and 514.3 °C to 269.8 and 452.7 °C, respectively. In addition, f(α) is [−ln(1 − α)]2 for tri-fuel in most mixing ratios when α < 0.5, while f(α) becomes [−ln(1 − α)]3 at α > 0.5. At a high-HTB-level mixing ratio, increasing the OS content causes a decrease in activation energy to 35.87 kJ mol−1. The moderate blending of oil sludge improves the pre-finger factor and the combustion performance.

Boronic acid functionalized silica‐coated Fe3O4 as a novel magnetically separable catalyst for the synthesis of hydrazinyl thiazoles

A novel silica‐coated magnetite supported boronic acid functionalized nanocatalyst (Fe3O4@SiO2‐Pr‐N=CH‐C6H4B[OH]2) was synthesized using a simple synthetic protocol. The catalyst was fully characterized by using Fourier transform‐infrared (FT‐IR), X‐ray diffraction (XRD), energy dispersive X‐ray (EDX), thermogravimetric analysis‐differential thermal analysis (TGA‐DTA), field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM) techniques. The structural investigations revealed that the catalyst is nano‐sized (average crystallite size 13 nm), spherical, thermally stable, and magnetic in nature having a magnetic saturation of 51.26 emu/g. The catalytic activity of Fe3O4@SiO2‐Pr‐N=CH‐C6H4B(OH)2 was explored in the synthesis of hydrazinyl thiazoles via one‐pot, three‐component reaction of phenacyl halide, thiosemicarbazide and aryl aldehyde in EtOH:H2O (50:50, v/v) at room temperature and it gave above 90% yields of hydrazinyl thiazoles. The catalyst being magnetically separable can be reused six times with the retention of catalytic activity. The present approach offers the advantages of operational simplicity, shorter reaction time, ambient reaction condition, facile separation of catalyst, and higher yields of the products.

Solvent-free synthesis of jasminaldehyde over chitosan–layered double hydroxide catalyst assisted by microwave irradiation

This research paper reports on the use of chitosan-modified layered double hydroxide (LDH) composite catalysts (CS/MgAl–NO3) for the synthesis of jasminaldehyde under microwave irradiation. The catalysts were prepared by co-precipitation in an inert nitrogen atmosphere. The resulting samples were characterized by mean of X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric/differential thermal analysis (TGA/DTA), scanning electron microscope (SEM) with energy-dispersive X–ray (EDX), and N2 adsorption/desorption isotherm (BET) analysis. The basicity of each catalyst was determined by the acid-base titration method. The performance of the catalysts was evaluated in the solvent-free synthesis of jasminaldehyde from aldol by condensation reaction between benzaldehyde and 1–heptanal in a microwave oven at P = 100 W and T = 90 °C. The effects of different parameters that are involved in the reaction, such as the catalyst amount and the benzaldehyde to 1–heptanal molar ratio, and reaction temperature, are investigated in detail. The results showed that the CS-functionalization of the catalyst leads to the enhancement of its basic sites making it more efficient than the naked MgAl–NO3 catalyst, in terms of the initial reaction rate, the conversion of the reactants and the selectivity toward the jasminaldehyde. The CS/MgAl–NO3 catalyst was also evaluated in successive regeneration reaction cycles.

Improvement in spectroscopic properties of Dy3+ doped Ba2Mg(PO4)2 phosphors through substitution strategy

In this work, we have synthesized Dy3+ activated Ba2Mg(PO4)2 phosphors by cationic/anionic substitution strategy. We have substituted Ca, Sr and VO4 in Ba2Mg(PO4)2 host lattice. These phosphors were synthesized by a high-temperature solid-state reaction method at 700 °C. The prepared samples' phase formation, thermal stability, photoluminescence properties and CIE coordinate were discovered in detail. The phase purity, morphology, functional groups and thermal stability of the prepared materials were investigated using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Fourier transform infrared (FT-IR) and Thermogravimetric – differential thermal analysis (TG-DTA) techniques. The Photoluminescence (PL) properties of Ba2Mg1−x(PO4)2:xDy3+, Ba2Mg1−x-ySry(PO4)2:xDy3+, Ba2Mg1−x-yCay(PO4)2:xDy3+ and Ba2Mg(1−x)(PO4)2−z(VO4)z:xDy3+ phosphors were studied in detailed. Under the different excitation wavelengths, the PL emission spectra show two characteristic peaks in the blue and yellow regions. In this study, the effect of cationic/anionic substitution has also been investigated. By co-doping (Sr2+, Ca2+, VO43-) ions, it was observed that the PL emission intensity increased significantly. The Commission Internationale de l′Elcairage (CIE) coordinates and color correlated temperature (CCT) of prepared samples were also calculated using ORSRAM SYLVANIA color calculator. The observed results revealed that Dy3+ activated Ba2Mg(PO4)2 phosphor and Sr2+, Ca2+, VO43- co-doped samples have potential applicability for detailed future studies in the field of lighting and display devices.

Utilization of mill rejects with biomass pellets in the existing coal power plants- a novel approach towards sustainability & fuel security

ABSTRACT The present work is focused on the possible utilization of mill rejects blended with the biomass non-torrefied pellets (made of paddy straw, dry grasses and fallen sal leaves) in the existing tangential coal-fired boiler through the gasification process. The physio-chemical analysis and combustion behavior study of the materials is done based on thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA). The result shows that the gross calorific value (GCV) of the developed bio-mass pellet is about 3900–4300 kCal/kg with the mass percentage of fixed carbon (FC) and volatile matter (VM) of about 15% and 70%, respectively. From the TGA and DTG study, it is observed that about 7% weight loss was found in all pellets at a temperature range of about 85–110°C but for the mill rejects, it is about 5–6%. At the peak temperature, the maximum weight loss of pellets and mill rejects is about 0.90 gm/min and 0.16 gm/min, respectively. The combined use of mill rejects and pellets (1:1) in the updraft gasifier generates combustible syngas with mole fractions of CO and H2 of about 0.29 and 0.30, respectively with a lower heating value of about 159 kJ/mole. The direct use of generated combustible syngas into the coal-fired boiler of a 500 MW power plant increases the net energetic and exergetic performance by about 0.09 and 0.07% points, respectively and resulting in a reduction of annual CO2 emissions by about 9452 tons. Cost-benefit analysis is used to determine the feasibility of the system.

Pyrazole and Benzimidazole Derivatives: Chelating Properties Towards Metals Ions and their Applications

Abstract: Due mainly to their structural diversities, pharmacological, electrochemical, and photophysical properties, the metal synthesis pyrazole and benzimidazole complexes were extensively designed and developed. The nitrogen-containing ligands playing an important role in coordination chemistry contain a wide variety of heterocyclic systems possessing one or more nitrogen atoms as electron donors, such as pyridine, isoxazole, pyrazole, 1,2,4-triazole, 1,3,5-triazine, quinoline, quinoxaline and benzothiazole. The structure of all ligands and the corresponding metal complexes are established using elemental analysis, infrared spectroscopy, NMR spectroscopy, mass spectrometry, single-crystal X-ray diffraction, thermogravimetric differential thermal analysis, static, magnetic susceptibility measurements, electron paramagnetic resonance spectroscopy (EPR), UV-Vis spectroscopy, and conductivity measurements.In this review, we report the synthesis and the chelating reactions of several heterocyclic ligands with various metals such as transition metals and lanthanides. The photophysical and photochemical properties of the metal complexes will also be presented and discussed.

Comparison of pesticide adsorption efficiencies of zeolites and zeolite-carbon composites and their regeneration possibilities

The presence of pesticides in our environment is a consequence of intensive industrial and civilizational development, necessitating the search for effective and safe methods to remove them. We suggest utilizing zeolite X and a zeolite-carbon composite, obtained through the chemical transformation of fly ash, as pesticide sorbents. To increase the sorption efficiency of 2,4-dichlorophenoxyacetic acid (2,4-D), 2-methyl-4-chlorophenoxyacetic acid (MCPA), carbendazim, and simazine, we functionalized the zeolite materials with cationic (hexadecyltrimethylammonium) and nonionic (Triton X-100) surfactants. We used transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric/differential thermal analysis (TG/DTA) and point of zero charge (pHpzc) analysis to characterize the functionalized sorbent materials. Our results indicate that cationic surfactants significantly enhance the adsorption of 2,4-D and MCPA. In contrast, carbendazim and simazine exhibit maximum sorption on the unmodified zeolite-carbon composite. The sorption mechanism is intricate, with physical sorption predominating, primarily due to electrostatic interactions between the protonated binding sites of the adsorbents and the negatively charged pesticide molecules. Regeneration tests demonstrated that ethanol is the most effective in regenerating zeolite-carbon composite with adsorbed MCPA and 2,4-D, while thermal regeneration was not possible. Adsorbents with simazine and carbendazim can be regenerated using both thermal and ethanol methods, but the thermal regeneration of zeolite with adsorbed simazine is more efficient. Utilizing functionalized zeolite materials obtained from industrial waste, such as fly ash, could provide an efficient way to remove pesticides from the environment.

Optical, thermal and gamma ray attenuation characteristics of tungsten oxide modified: B2O3–SrCO3–TeO2–ZnO glass series

The glass series modified by tungsten oxide was created using the compounds (75-x) B2O3– 10SrCO3– 8TeO2– 7ZnO - xWO3, where x = 0, 1, 5, 10, 22, 27, 34, and 40% mole percentage. A UV–visible spectrophotometer and thermogravimetric-differential thermal analysis (TG-DTA) methods were employed to characterize the specimen's optical and phase transition attributes, respectively. The mass-attenuation coefficient (AC) of all created glasses from BSTZW0 to BSTZ7 was estimated using Geant4 code from 0.05 to 3 MeV and compared to the XCOM software results, with a relative difference of less than 2% between the two results. The increase of WO3 percentage lead to an increase in the Linear-AC at each studied energy, and this is mainly due to the fact that the higher the percentage of WO3 in the glass increases its density which causes an increase in the Linear-AC, so an energy of 0.06 MeV, as an example, the values of the Linear-AC was 4.009, 4.509, 5.442, 6812, 8.564, 9.856, 10.999 and 11.628 cm−1 form BSTZW0 too BSTZW7, respectively. The Half-VL (value layer), Mean-FP (free path), Tenth-VL, and Radiation attenuation performance (RAP) were also calculated for the current BSTZW-glass samples and revealed that BSTZW7 had the best gamma ray attenuation performance at all discussed energies when compared to other studied glass samples.

Synthesis and characterization of UV and thermal curable polybenzoxazine/silica nanocomposites

AbstractIn this study, it was aimed to synthesize and characterize UV and thermally curable polybenzoxazine/silica nanocomposites as high performance coating materials. For this purpose, synthesis and characterization of allyl‐functional benzoxazine monomers and thiol‐functional silica nanoparticles were performed to carry out UV polymerization. Allyl functional benzoxazine monomers were characterized by FT‐IR (Fourier Transform Infrared) and 1H NMR (Nuclear Magnetic Resonance) spectroscopy techniques. Using the obtained benzoxazine monomers and silica nanoparticles, polybenzoxazine/silica nanocomposites in various formulations were prepared by UV and thermal curing. Structural characterization of prepared nanocomposites were analyzed by FT‐IR spectroscopy technique. The thermal and mechanical properties of the nanocomposite films were analyzed by TGA/DTA (Thermogravimetric Analysis/Differential Thermal Analysis) and DMA (Dynamic Mechanical Analysis). Morphological structures were investigated by SEM (Scanning Electron Microscopy) and particle distributions were investigated by EDS (Energy Dissipative X‐Ray Spectroscopy). In addition, gel contents and water absorption capacities of the samples were determined. It was determined that thiol functional nanosilica reinforcement increased the thermal and mechanical strength of nanocomposite films and the optimum amount of thiol functional nanosilica to be added at room temperature was 1 mmol. When all the results obtained were evaluated, it was concluded that nanocomposite films with superior thermal and mechanical properties that could be used in the coating industry were produced.

Photoluminescence and thermoluminescence properties of pure and rare-earth-doped ZrO2 prepared by Pechini-type sol-gel.

In this article, photoluminescence (PL) and thermoluminescence (TL) properties of ZrO2 , ZrO2 :Dy3+ , ZrO2 :Dy3+ -Gd3+ , ZrO2 :Dy3+ -Yb3+ , ZrO2 :Dy3+ -Er3+ , and ZrO2 :Dy3+ -Sm3+ phosphors synthesized by the Pechini method were investigated. The crystal structure, thermal properties, morphology, PL and TL properties were investigated using X-ray powder diffraction (XRD), differential thermal analysis/thermogravimetric analysis (DTA/TGA), scanning electron microscopy (SEM), PL and TL, respectively. The room temperature emission bands corresponding to 4 F9/2 →6 HJ (J= 9/2, 11/2, 13/2 and 15/2) transitions of Dy3+ ions were measured. The phosphors were analysed using Tm -TSTOP , variable dose, and computerized glow curve fitting methods. Reusability, dose-response, and fading characteristics were investigated. The phosphors have a natural TL emission that vanished by heating treatment. Moreover, new peaks with similar properties to the natural emissions were observed after high-dose irradiation and long-term fading experiments. The glow curves of the phosphors have 13 individual peaks and many low- and high-temperature satellite peaks. The origin of the peaks is ZrO2 host material and doping with rare-earth ions (Gd3+ , Dy3+ , Yb3+ , Er3+ and Sm3+ ) does not lead to a new glow peak. The dopants cause drastic changes in individual peak intensities of ZrO2 .The initial fading rates of all the phosphors are relatively fast, but they slow down as time goes on.

Synthesis, structural, spectral, thermal, and optical characterization of a new curcumin derivative: A promising material for NLO applications

A novel Curcumin derivative 1-(4-chlorobenzoyl)-3,5-bis((E)-3,4-dimethoxybenzylidene)piperidin-4-one (CDMBP) has been synthesized by Claisen-Schmidt condensation and Schotten-Baumann reaction methods. CDMBP single crystal was grown from acetone by slow evaporation method at ambient temperature. The crystal structure of the compound was derived by Single Crystal X-ray Diffraction studies (SCXRD). The title compound CDMBP was crystallized in a triclinic crystal system with a P ͞1 space group. NMR spectral analysis reveals the different types of carbon and proton in the molecular structure of the title compound. The modes of vibrations of different chemical groups were identified using FT-Raman and Fourier Transform Infrared spectral analysis (FTIR). Utilizing the UV–Vis spectrum, the cutoff wavelength and linear optical constants such as the band gap, extinction coefficient, and refractive index were calculated. The Photoluminescence spectrum (PL) has been studied and it shows a high-intensity peak at 504 nm and belongs to the green emission radiation region. Fluorescence profiling of the compound was done to get an outline of the emission features of the excited states with the emission decay mechanisms using Lifetime measurements. The third-order nonlinear optical property (NLO) of CDMBP was investigated in detail using a Z-scan technique with a He–Ne laser at 632.8 nm as a laser source. The nonlinear optical susceptibility (χ3), absorption coefficient (β), and refractive index (n) were calculated using transmittance data. The thermal stability of the grown crystal was investigated from the Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA).

A comparative study of surface modified nanohydroxyapatite using PVA polymer extracted from Seashells, Coral Skeletons and Eggshells for biomedical applications

The necessity and usage of hydroxyapatite in the form of bone and dental substitutes are increasing day by day. Hydroxyapatite derived from natural biomaterials promotes better osteointegration and biocompatibility with host bone. The present investigation aims to compare the properties of three distinct naturally occurring calcium precursors (seashells, coral skeletons, and eggshells) derived from nHAp/PVA composites (Polymeric composites). All the prepared samples were examined through characteristic instruments such as XRD (X-ray diffraction), FT-IR (Fourier Transform Infrared) Spectroscopy, TG-DTA (Thermogravimetric-Differential Thermal Analysis), SEM/EDAX (Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy), and XPS (X-Ray Photoelectron Spectroscopy). Furthermore, the samples were subjected to the Simulated Body Fluid (SBF), Hemocompatibility and Antimicrobial assay to find the Bioactivity, Hemocompatible and Antibacterial efficiency of the samples. The surface morphology of seashell nHAp/PVA shows a spherical shape while coral and eggshell-derived nHAp/PVA exhibits rod-shaped morphology. However, the achieved particle is found to be in the range of 32 to 41 nm. Also, coral-derived nHAp/PVA composites show a maximum crystallinity of 83.7% with a minimum weight loss of about 49.96%. This study demonstrates that among the prepared samples, coral nHAp/PVA performs better, but in terms of availability, seashell/PVA takes the lead with good results in all aspects. Though the eggshell nHAp/PVA satisfies several characteristic studies, it shows less stableness on TG-DTA. This study suggests that both Seashells and Corals can be utilized as calcium precursors in the making of quality hydroxyapatite that can be further processed in the making of hard tissue replacements/substitutes.

The Kinetic Mechanism of the Thermal Decomposition Reaction of Small Particles of Limestone at Steelmaking Temperatures

Converter blowing limestone powder making slag steelmaking process has the advantages of low carbon and high efficiency, and can realize the resource utilization of CO2 in the metallurgical process, which is in line with the development direction of green metallurgy. Based on a thermogravimetric-differential thermal analyzer, the kinetic mechanism of decomposition of small limestone at steelmaking temperatures was investigated by a modified double extrapolation method. The results showed that with a higher rate of heating, limestone decomposition lagged, and decomposition temperature increased. Furthermore, the smaller the limestone particle size, the lower the activation energy of decomposition. Compared with N2, air, and O2, small limestone powder used for converter blowing could complete more rapid decomposition, and the time required for decomposition shortened by about 1/3, although the decomposition temperature increased in the CO2. The limestone decomposition rate increased and then decreased at low to high CO2 partial pressures. With a limiting link, the inhibition was more significant under high CO2 partial pressure, but the reaction can be fully completed by 1000 °C. The decomposition type modeled was stochastic nucleation and subsequent growth. As the partial pressure of CO2 increased from 25% to 100%, the number of reaction stages, n, increased.

Solvothermal syntheses and characterization of one-dimensional (1,4-dabH2)Cu1.72Ag0.28SnSe4 (1) and (1,4-dabH2)Cu2SnSe4 (2)

Here, two seleniumstannates (1,4-dabH2)Cu1.72Ag0.28SnSe4 (1) and (1,4-dabH2)Cu2SnSe4 (2) (1,4-dab = 1,4-diaminobutane), were synthesized successfully via solvothermal method, and an organic amine as the structural directing agent. Two compounds have similar structures: inorganic anionic chains and doubly protonated [1,4-dabH2]2+ organic cations. In this work, single-crystal and powder X-ray diffraction and thermogravimetric-differential thermal analysis (TG-DTA) are used to verify the above compounds, meanwhile, the optical and photoelectric properties were investigated, and the optical band gap is calculated as 2.43 and 2.46 eV, respectively. Furthermore, 1 and 2 exhibited photocurrent responses with photocurrent intensities of 3.83 μA/cm2 and 1.54 μA/cm2, respectively. Additionally, the compounds degrade methylene blue (MB).

Thermal, chemical and physical analysis of VDW.1Seal, Fill Root ST, and ADseal root canal sealers

This study aimed to evaluate the thermal, chemical, and physical properties of VDW.1Seal, Fill Root ST, and ADseal sealers. Thermal properties were analyzed using Thermogravimetric analysis (TGA) and Differential thermal analysis (DTA). Attenuated total reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) analysis was performed as a complementary test to confirm TGA/DTA analysis. The chemical composition of the set sealer material was identified using an X-ray powder diffraction (XRD) system. Other physical properties of each sealer were investigated; ten specimens were used to measure the solubility (at 24 h and 28 days), and another ten specimens were used to assess pH changes and calcium ion release (after 7 and 14 days). Film thickness was done according to ISO 6876 specs. The data were analyzed using the two-way ANOVA test. Results showed that for all sealers, TGA analysis revealed a direct relationship between sealer mass loss and temperature rise. In addition, the decomposition of the tested sealers started at 145 °C, 135 °C and 91 °C for VDW.1Seal, ADseal sealer, and Fill Root ST, respectively. XRD analysis revealed a higher degree of crystallinity for VDW.1Seal and ADseal. ADseal showed the least solubility; VDW.1Seal exhibited the highest alkalinity, calcium ion release, and the lowest film thickness.

Green Synthesis of Silver Nanoparticles Derived from Papaver rhoeas L. Leaf Extract: Cytotoxic and Antimicrobial Properties.

In the last few decades, the search for metal nanoparticles as an alternative to cancer treatments and antibiotics has increased. In this article, the spectroscopic (ultraviolet-visible (UV-vis), electron-dispersing X-ray (EDX), and Fourier transform infrared (FT-IR)), microscopic (field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), and atomic force microscope (AFM)), structural (X-ray diffractometer (XRD) and zetasizer), and analytic (thermogravimetric/differential thermal analyzer (TGA-DTA)) characterization of the silver nanoparticles (AgNPs) produced from Papaver rhoeas (PR) L. leaf extract are presented. PR-AgNPs are generally spherical and have a maximum surface plasmon resonance of 464.03 nm. The dimensions of the manufactured nanomaterial are in the range of 1.47-7.31 nm. PR-AgNPs have high thermal stability and a zeta potential of -36.1 mV. The minimum inhibitory concentration (MIC) values (mg L-1) of PR-AgNPs on Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Candida albicans are 1.50, 0.75, 3.00, 6.00, and 0.37, respectively. In the study, the cytotoxic and proliferative effects of PR-AgNPs using the MTT (3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide) method on various cancer cell lines (CACO-2 (human colon adenocarcinoma cell), MCF-7 (human breast cancer cell), T98-G (glioblastoma multiforme cell), and healthy HUVEC (human umbilical vein endothelial cell)) cell lines are presented. After 24 and 48 h of the application, the half-maximum inhibitory concentration (IC50) values (μg mL-1) of PR-AgNPs on HUVEC, CACO-2, MCF-7, and T98-G lines are 2.365 and 2.380; 2.526 and 2.521; 3.274 and 3.318; 3.472 and 3.526, respectively. Comprehensive in vivo research of PR-AgNPs is proposed to reveal their potential for usage in sectors such as nanomedicine and nanochemistry.

Influence of Integration of Iron Ore Tailings on the Physio-mechanical and Microstructure Properties of Fly Ash–Based Coarse Aggregates

Abstract The goal of this experimental study is to produce fly ash (FA)-based coarse aggregates by adding iron ore tailings (IOT) to the FA-based precursor as an additional mix component. The involvement of different types of binders—influential factors of both pelletization and geopolymerization that govern the production of FA-based coarse aggregates—was experimentally designed by adopting Taguchi’s experimental design. An evaluation was conducted utilizing response indexes at three curing periods to study the accumulation of all the influencing factors in the production process as well as on the engineering features of IOT admixed FA-based coarse aggregates. Aggregate impact and crushing values, individual pellet strength (IPS), and specific gravity and water absorption values were measured. According to experimental findings, IOT addition considerably affects the engineering characteristics of FA-based coarse aggregates. The heat resistance of the produced aggregates was found to be improved by the presence of different sodium oxide dosages and blending ratios (IOT:FA) based on analysis through scanning electron microscopy and thermogravimetric differential thermal analysis. The role of IOT in associative formation of calcium silicate hydrate is demonstrated by increasing calcium hydroxide, which supports increasing IPS values of produced aggregates. From the 1st to the 200th day of curing age, Fourier-transform infrared spectroscopy studies between the best- and worst-performing mixes showed two things: first, the emergence of new peaks with time, and second, the observation of major bands shifting to lower and higher wavenumbers, which was found to be directly correlated to the performance of the aggregates.