TG DTA Research Articles

Hydration kinetics of C3A: effect of lithium, copper and sulfur-based mineralizers

AbstractCalcium aluminate phases have a particular effect on the early heat release during setting initiation and have a substantial influence on the further workability of ordinary Portland cement. The nature of the calcium aluminate hydration products and its kinetics strongly depends on sulfate content and humidity. The effect of mineralisers on melt formation and viscosity is well described for calcium silicate systems, but information is still lacking for calcium aluminates. Therefore, the synergistic effect on the crystal structure and hydration mechanism of the tricalcium aluminate phase of the addition of mineralizers, i.e. Li2O, CuO, SO3 to the raw meal is here investigated. Co-doped calcium aluminate structures were formed during high-temperature treatment. Thermal analysis (TG–DTA and heating microscopy) was used to describe the ongoing high-temperature reaction. Resulting phase composition was dependent on the concentration of the mineralizer. While phase pure system was prepared with low mineralizer concentrations, with increasing mineralizer content the secondary phases were formed. Raman spectroscopy and XPS analysis were used to investigate the cation substitution and to help describe the cations bonding in co-doped calcium aluminate system. Prepared powders have been hydrated in a controlled manner at different temperatures (288, 298, 308 K). The resulting calorimetric data have been used to investigate the hydration kinetics and determine the rate constant of hydration reaction. First-order reaction (FOR) model was here applied for the activation energy and frequency factor calculations. The metastable and stable calcium aluminate hydrates were formed according to initial phase composition. In phase pure systems with low S content, the formation of stable and metastable hydrates was depended on the reaction temperature. Conversely, in systems with secondary phases and higher S content, the hydration mechanism resembled that which appears in calcium sulfoaluminates.

Mineralogical and leaching characteristics of sulfur concentrate and hot filter residue from zinc–oxygen-pressure leaching

The mineralogical properties and environmental impact of sulfur concentrate and hot filter residue produced from the zinc–oxygen-pressure leaching were studied through a series of characterization, including X-ray fluorescence (XRF), inductively coupled plasma optical emission spectroscopy (ICP–OES), X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDS), particle size distribution (PSD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and thermogravimetry and differential thermal analysis (TG–DTA). Furthermore, short-term environmental activity was assessed using the toxic leaching procedure (TCLP). The results indicated that the sulfur concentrate exhibited a coarser particle size compared with the hot filter residue, primarily appearing as spindle-shaped element sulfur (S0). The hot filter residue contained spindle-shaped S0 and rod gypsum, alongside phases of sphalerite, pyrite, and copper–silver-containing phases encapsulated by S0, recovering valuable metals first requires the removal of S0. The surfaces of both sulfur concentrate and hot filter residue were composed of S, ZnS, Al-O, PbSO4, and SiO2. They exhibited thermal instability and some degree of water absorption, with vigorous burning observed at temperatures ranging from 200 °C to 380 °C. The leachates from these materials exhibited increased concentrations of elements such as zinc, lead, and cadmium surpassing permissible limits, highlighting the importance of their safe disposal for the stable production of zinc–oxygen-pressure systems.

Effects of mixing water and environmental pH value on the properties of sulfoaluminate cement-based ultra-high water materials

In order to grasp the influence of the pH value of mixing water and environmental water on the properties of ultra-high water materials, this article separately carried out the influence of different pH values of mixing water on the properties of ultra-high water materials and the conservation of high-water materials in water environments with different pH values. Using test methods such as loss of flow time, compressive strength, Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), Thermogravimetric-Differential Thermal Analysis (TG–DTA), to conduct regular exploration and mechanism analysis. The study found that with the continuous increase of the pH value of the mixing water, the loss of flow time of the ultra-high water material gradually decreased, and the compressive strength of the samples at the same age continued to increase. A lower pH value will affect the compressive strength of the consolidated body of the ultra-high water material, but when the pH = 13 in the reaction solution, the compressive strength of the consolidated body will no longer increase and begin to produce a weakening effect. The pH of the construction water for ultra-high water materials is recommended to be 4–13. At the same time, it was found that under the conservation of an acidic environment, the consolidated body was severely eroded and the strength loss was large. The acid–base environment of the goaf suitable for filling with the ultra-high water material should be between pH = 7–10 to ensure that the filling body is not weakened by erosion.

Novel sol-gel route for expanding the glass forming region of tin phosphate glass for secondary battery electrode applications

In this paper, tin-phosphate amorphous glass and nano-crystallized ceramic materials were synthesized by sol-gel methods and heat treated at 400 °C with the composition of xSnO2− (100-x)P2O5 (xSnP: ‘x’ from 40 to 90 mol%). The electrical and thermal properties of tin-phosphate materials were investigated by electrical impedance spectroscopy (EIS) and thermogravimetry – differential thermal analysis – mass spectroscopy (TG–DTA–MS). Moreover, the local structure of xSnP was characterized by 119Sn-Mössbauer and magic angle spinning (MAS) 31P NMR spectroscopies. Homogeneous glasses were obtained for xSnP with ‘x’ from 50 to 80, while Sn(HPO4), SnO2, and Sn3(PO4)2 nanoparticles formed in 40SnP and 90SnP compositions, respectively. The nano-crystallized 40SnP and 90SnP samples showed large electrical conductivity (σ) of 2.02×10−5 and 1.04×10−4S cm−1 due to the conductive crystalline phases of SnP2O7 and defective SnO2, respectively. The lower σ of about 10−8S cm−1 were recorded for xSnP with ‘x’ from 50 to 80 owing to the decomposition of the 3D network built by phosphate tetrahedrons. 119Sn-Mössbauer spectra proved the growing number of SnIVO6 units, which do not contribute to the rise of electrical conductivity. On the other hand, larger σ values of 1.79×10−4 and 6.4×10−3S cm−1 were confirmed for 40SnP and 90SnP samples after heat treatment, resulting in partial reduction of SnIV to SnII and growing of the 3D network structure by PO43−. It is concluded that highly electrically conductive xSnP samples can be synthesized by the sol-gel method followed by slow heat treatment. In addition, the battery evaluation was performed of xSnP samples as cathode and anode in a sodium-ion battery. The highest initial capacity recorded for 90SnP nano-crystallized ceramic at 37.97 mAh g−1 under a current rate of 20 mA g−1 with capacity retention (%) of 48.15% after 100 cycles as a cathode material. The anode test showed that the 40SnP nano-crystallized ceramic has the largest initial capacity of 375 mAh g−1 and after heat treatment 50SnP glass significantly increased to 425 mAh g−1 compared with 186 mAh g−1 before heat treatment. Also, the heat treatment effect on the initial capacity of 90SnP nano-crystallized ceramic with observation largest value of 470 mAh g−1. These results open the way to maybe applying these glass and nano-crystallized ceramic materials in all-solid-state batteries.

The reactivity of CeO2 towards MoO3 in air atmosphere – reinvestigation

AbstractIt is known that both the type and possibilities of application of cerium molybdates(VI) largely depend on the methods of their synthesis. Despite this, information on the type of molybdates(VI) formed as a result of a waste-free and environmentally friendly reaction occurring in the solid state between CeO2 and MoO3 in the air atmosphere, are divergent. The conducted research indicates that CeO2 and MoO3 react in air and in the temperature range of 500–650 °C to form two compounds, i.e. Ce5Mo8O32 and/or Ce2Mo4O15. Only the Ce5Mo8O32 compound, for the first time, was obtained as a pure phase. The synthesis of Ce5Mo8O32 takes place through an intermediate stage. In this stage, with the evolution of oxygen, the compound Ce2Mo4O15 is formed, which then reacts with excess CeO2 to Ce5Mo8O32. The obtained compound was characterized by XRD, DTA–TG, FTIR and UV–Vis/DRS methods. Ce5Mo8O32 has a green-olive colour and a density of 4.82 ± 0.05 g cm−3. It was found that this compound melts incongruently at the temperature of 960 ± 5 °C with the separation of solid CeO2. The value of the energy gap Eg ~ 2.59 eV allows the Ce5Mo8O32 compound to be classified as a semiconductor. The previously unknown properties of the compound with mixed cerium valence (Ce 4 3+ Ce4+Mo 8 6+ O32), characterized in this work, will constitute the basis for its application research.

Synthesis and crystal structure of diisothiocyanatotetrakis(4-methylpyridine N-oxide)cobalt(II) and diisothiocyanatotris(4-methylpyridine N-oxide)cobalt(II) showing two different metal coordination polyhedra

The reaction of Co(NCS)2 with 4-methylpyridine N-oxide (C6H7NO) leads to the formation of two compounds, namely, tetrakis(4-methylpyridine N-oxide-κO)bis(thiocyanato-κN)cobalt(II), [Co(NCS)2(C6H7NO)4] (1), and tris(4-methylpyridine N-oxide-κO)bis(thiocyanato-κN)cobalt(II), [Co(NCS)2(C6H7NO)3] (2). The asymmetric unit of 1 consists of one CoII cation located on a centre of inversion, as well as one thiocyanate anion and two 4-methylpyridine N-oxide coligands in general positions. The CoII cations are octahedrally coordinated by two terminal N-bonding thiocyanate anions in trans positions and four 4-methylpyridine N-oxide ligands. In the extended structure, these complexes are linked by C—H...O and C—H...S interactions. In compound 2, two crystallographically independent complexes are present, which occupy general positions. In each of these complexes, the CoII cations are coordinated in a trigonal–bipyramidal manner by two terminal N-bonding thiocyanate anions in axial positions and by three 4-methylpyridine N-oxide ligands in equatorial positions. In the crystal, these complex molecules are linked by C—H...S interactions. For compound 2, a nonmerohedral twin refinement was performed. Powder X-ray diffraction (PXRD) reveals that 2 was nearly obtained as a pure phase, which is not possible for compound 1. Differential thermoanalysis and thermogravimetry data (DTA–TG) show that compound 2 start to decompose at about 518 K.

Enhanced electrochemical and thermal stability of CdS:Pb2+, Cu2+ co-doped nanoparticles on energy storage applications

For the first time, we prepared the Pb2+, Cu2+ co-doped CdS nanoparticles that were prepared by a simple chemical precipitated method. Structural and lattice parameters were determined by XRD. It was found that mixed cubic-hexagonal crystal structure for the co-doped nanoparticles. Polyvinylpyrrolidone (PVP) was used as a surfactant to control particle size. The organic functional group's presence in the surfactant was identified by FT-IR. Two distinct morphologies were found for the co-doped sample that was studied by TEM. TG–DTA was used to study thermal stability and phase transition of the sample. CV analysis was used to determine the potential window of oxidation and reduction of the sample. In addition, VSM exhibits diamagnetic behavior for CdS:Pb:Cu nanoparticles. We found that the excellent electrochemical, thermal and magnetic properties of the co-doped CdS nanoparticles can be used for electrochemical energy storage applications.

Influence of nanosilica in the chloride binding capacity of sustainables ground blast furnace slag and metakaolin

This work investigates the chloride binding capacity combine of two sustainable pozzolanic additions such as granulated blast furnace slag (G) and metakaolin (M) used in cement to decrease its carbon footprint. They are also combined with two nanosilicas with different specific surface area (O and A). Blends of alone M or G and with nanosilica are mixed in water with Ca(OH)2 and chloride (C) to compare chloride binding capacity of both in presence or not of nanosilica. Blends are analysed by XRD, FTIR, DTA–TG and chloride binding capacity is determined too by potentriometric titration with AgNO3. The addition of chlorides to both pozzolanic M and G indicates that M shows higher chloride binding capacity than G although very similar Friedel's salt formation, indicating a higher physisorbed chlorides contain. Chlorides addition meaningfully replaces carbonates in carboaluminates phases to form Friedel's salt, being this exchange higher for samples with M than for G blends. The combination of experimental techniques used in this study have shown that the effect of nanosilica addition to samples with M and G show an opposite effect in Friedel's salt formation, increasing for samples with G and decreasing for samples that contain M.

A novel aspect on different preservation methods for tomato paste by examining the protective effect of herb and spice oils.

In this study, the effect of essential oils of herbs and spices on the protection of homemade tomato paste without additives was investigated. Garlic oil was used as plant essential oil and thyme oil was used as spice essential oil. Samples were kept without adding essential oils at the specified holding times in determined light and dark ambient conditions. After the test period of the prepared setups was completed, the amount of mold formed in the tomato paste was observed, and the optimum samples were determined as K4A4, K4K7, K4K13, K6K10, S6K4, S6K7, S6K10, S6A13 by weighing again and creating a %-time graph by mass. It was decided that thyme essential oil had a more protective effect in foods than garlic essential oil, with the analysis methods performed on optimum samples (Physical analysis, microbiological analysis, FT-IR, and TG DTA).

Investigation of physico-chemical properties and evaluation of the biological potential of essential oil extracted from Artemisia pallens

Artemisia pallens, an aromatic and medicinal plant occasionally referred to as Davana is a member of the Asteraceae family. Understanding the physiochemical and therapeutic properties of Davana essential oil (DEO) is the major aim of this study. Essential oil from plant material was extracted using the hydro-distillation method. Examination of the phytochemical components and several plant constituents from the whole oil were detected using GC–MS analysis and some components were Isobutyl propionate, 4,5-Dimethyl-Thiazole, Ligustrazin, Endo-2-Norborneol, Tetradecanoic acid, and Octadecanoic acid. The thermal stability of the oil was tested using thermoanalytical studies such as TG–DTA and DSC. Moreover, to comprehend the biological potential of the oil antimicrobial, antituberculosis, antimalarial, antioxidant, anticancer, and antibiofilm activities were investigated essential oil was tested for antimicrobial activity against 10 bacterial and 7 fungal strains. The antimalarial potential was evaluated against Plasmodium falciparum. Cytotoxicity of the DEO was determined against MCF-7, HeLa, and CHO cell lines employing MTT assay. Meanwhile, the DPPH assay was adopted to assess antioxidant potential, and the ability to suppress biofilm formation was also assessed. The study’s findings reveal that Artemisia pallens is a reservoir of natural compounds and can be used against numerous ailments.

Physico–chemical and extraction properties on alkali–treated Acacia pennata fiber

The production of reinforced composite materials can generally benefit greatly from the use of natural cellulosic woody fibers as good sustainable resources. Natural plants like hemp, cotton, and bamboo are great options for knitters and crocheters looking to make eco–friendly goods. The current study examines the properties of natural fiber obtained from the stem of the Acacia pennata (AP) plant, as well as its basic physico–chemical, structural, thermal, and mechanical characteristics. The key goal of this work was to investigate how alkali treatment affected the AP fibers' morphology, chemical composition, tensile capabilities, morphological changes, structural changes, and thermal degradation (APFs). The SEM image and pXRD analyses support the improved surface roughness of the fiber, and that was seen after the alkaline treatment. From XRD analysis, the fiber crystallinity index (54.65%) was improved and it was connected to their SEM pictograms in comparison to untreated APF. Alkali–treated AP fibers include a higher percentage of chemical components including cellulose (51.38%) and ash (5.13%). Alkali–treated AP fibers have a lower amount of hemi–cellulose (30.30%), lignin (20.96%), pectin (8.77%), wax (0.12%), and moisture (13.44%) than untreated APF. Their low density and high cellulosic content will improve their ability to fiber matrices. The thermal behavior of AP fiber at various temperatures was demonstrated by TG–DTA analysis, and tensile strength was also investigated.

Ultrafast photodegradation of textile industry dyes using efficient sulfide based ternary nanocomposites

We developed novel zinc-cadmium-bismuth sulfide (Zn–Cd–Bi2S3) and Zn–Cd–SnS nanocomposites to fabricate a heterojunction by an easy chemical technique to improve photocatalytic degradation of textile dye. Crystalline size and lattice parameter are analyzed using X-ray diffraction (XRD) spectrometer. The obtained strong diffraction peaks with various diffraction planes confirm the fabrication of a high crystal quality nanocomposite as well as the identification of its mixed crystal structure. The morphological information is studied using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (TEM). Due to its higher surface energy, the as-prepared nanocomposite displayed agglomeration by adjoining to tiny particles. The roughness of surface is studied by atomic force microscopy (AFM). Fourier transform-infrared spectroscopy (FT-IR) used to study about presence of organic functional groups on the surface of nanocomposite. Using UV–Visible and photoluminescence spectra, the impact of shifting the positions of Sn and Bi ions on the optical characteristics is investigated. Thermal property of the nanocomposite is studied by thermogravimetric–differential thermal analysis (TG–DTA) at air atmosphere. We examine and compared the photocatalytic activity of Zn–Cd–Bi2S3 and Zn–Cd–SnS nanocomposites for the crystal violet (CV) dye. Under the sun light irradiation Zn–Cd–Bi2S3 nanocomposite demonstrated a highest percentage of degradation (88.5%) within a short period (120 min). The obtained photocatalytic results indicate that the active radicals •O2-, h+, and •OH- are favourable for the photocatalytic reaction. A possible photocatalytic mechanism for the dye degradation for the photocatalyst is proposed. Due to the narrow band gap, wide range of incident light captured by the heterostructure nanocomposite and the photogenerated electrons and holes is effectively separated in the Zn–Cd–Bi2S3.

Preparation, Characterization, Release and Antibacterial Properties of Cinnamon Essential Oil Microcapsules

In this study, the antibacterial microcapsules of cinnamon essential oil (CEO) were prepared by complex condensation method. Chitosan quaternary ammonium salt (HACC) combined with gum arabic (GA) was selected as the coated wall material. The optimal preparation conditions of CEO microcapsules (CMSs) were determined by response surface methodology (RSM): the core/wall mass ratio was 1:1, the pH value was 4.5, the mass concentration of CaCl2 was 0.7 wt% and the actual encapsulation rate of microcapsules was 90.72% ± 1.89%. The morphology, size, composition and thermal stability of the prepared CMSs were characterized by scanning electron microscopy (SEM), laser particle size analysis (LPDA), Fourier transform infrared spectroscopy (FTIR), thermogravimetric differential thermal analysis (TG–DTA) and differential scanning calorimetry (DSC). In addition, the in vitro drug release and antibacterial properties of CMS were also evaluated. The results showed that CMS was spherical, with an average particle size of 6.31 µm. The obvious weight loss occurred at 269 °C and the corresponding DSC curve had an obvious exothermic peak at 265.5 °C, which had an increase compared with CEO. Microcapsules can achieve slow release, with the lowest and highest release rates being 19.66% and 49.79%, within 30 days. The drug release curve of essential oil of microcapsules was consistent with a first-order release model named ExpDec1. Based on the above research results, the CMS can effectively improve the stability of essential oil, achieve slow release and prolong the antibacterial effect, indicating its potential applications in food, cosmetics and medicine.

Influence of Er/Fe Substitution on Mg-Zn Nanoparticles’ Electromagnetic Properties and Applications

Mg0.8Zn0.2ErxFe2-xO4 (x = 0.00, 0.005, 0.01, 0.015, 0.02, and 0.025) nanoparticles made using the citrate gel autocombustion process were examined for their structure, morphology, and behavior. The single-phase cubic spinel structure was formed according to the diffraction pattern. Observations revealed that as the Er focus went from to 0.0 to 0.025, the average crystallite size (D) increased from 12.4 to 18.6 nm. The findings of the SEM and EDAX analyses reveal that the particles are uniform, with just a little amount of agglomeration and no impurity pickup. Nanoparticles from transmission electron microscopes (TEM) were present, the range from 12 to 19 nm. In IR spectroscopy using the Fourier transform (FTIR), nearly all the spinel ferrites presented generate two absorption bands that have wavelengths of around 400 cm and 600 cm. The BET surface area of the Er3+ ion doping Zn-Mg ferrites rises from 23.860 m2/gm to 29.845 m2/gm. The TG–DTA analysis of the prepared samples confirms the thermal stability of the samples; the temperature ranges from 100 to 750 °C.The transition temperature (Seebeck coefficient) of the samples was studied using thermoelectric power (TEP) measurement studies, and it was found that all the samples showed N-type semiconductor behavior. With an increase in erbium concentration, DC conductivity decreases. At room temperature, the magnetic characteristics of hysteresis loops, squareness ratio (SQR), anisotropy constant (K), magnetic moment (), coercivity (Hc), saturation magnetization (Ms), and retentivity (Mr) were examined. When erbium concentration rises, the magnetic moment (B) increases. The saturation magnetization values were 288.4615 and 244.5266 emu/g, and squareness ratio values from 0.01554 to 0.03303 were observed. These materials are converted from hard permanent magnet materials to soft magnet materials.

Synthesis, characterization, and biological activities of five new trivalent lanthanide complexes of hydrazine and 3,3’-thiodipropanoic acid

Some new hydrazine complexes of trivalent lanthanide 3,3’-thiodipropanoates of empirical formulae [M(N2H5)(tdp)2] and [Pr(N2H5)(tdp)2·H2O], where M = La, Ce, Sm and Nd, H2tdp = 3,3’-thiodipropanoic acid, have been prepared and characterized by elemental analysis, mass, FTIR, Raman and electronic spectral, powder X-ray diffraction, scanning electron microscopy (SEM) and simultaneous TG–DTA techniques. The presence of bidentate carboxylate anion and coordinated N2H5 in these complexes are confirmed by IR spectra. TGA/DTA results confirmed that all the rare earth metal complexes give the corresponding metal carbonate (heating up to 1000 °C) through a metal oxalate intermediate. SEM images of Pr2O3 residue obtained from its complex show nano-sized clusters, thus the complex may be used as a precursor for nano-Pr2O3 preparation. The synthesized complexes show good antimicrobial activity against six bacteria (Bacillus cereus, Staphylococcus aureus, Proteus vulgaris, Pseudomonas aeruginosa, Escherichia coli, and Serratia species) and four fungi (Candida albicans, Aspergillus niger, Aspergillus fumigatus, and Penicillium variance) as assessed by in vitro biological activity.

Mechanistic aspects of in - situ combustion synthesis: Low Temperature gadolinium oxide formation during the high temperature interactions between gadolinium nitrate hexahydrate and glycine through solid state route

Current studies describe the application of simultaneous TG–DTA–EGA(FTIR) techniques in the in-situ synthesis of nano - sized gadolinium oxide through solid state route, using the high temperature interactions between Gadolinium nitrate hexahydrate and Glycine through in-situ combustion. Individual decomposition behavior of gadolinium nitrate hexahydrate, glycine and their interaction, in three different mole ratios, has been studied in inert and oxidative environments and respective reaction mechanisms have been proposed. It has been confirmed through thermal studies that gadolinium nitrate hexahydrate and glycine decompose independently in fuel deficient mixture. Results obtained from TG – DTA – EGA (FTIR), EDS and PXRD match well and suggests the formation of Gd2O3 at 400 0C. These studies confirm the formation of Gd2O3 at low temperature in inert environment using stoichiometric and fuel excess ratio mixtures.

Effects of Tuff Powder on the Hydration Properties of Cement-Based Materials under High Temperature

In some instances, traditional mineral admixtures, such as fly ash and slag, have been insufficient, and tuff powder (TP) has been used as an alternate replacement. However, the mechanisms of the hydration of tuff powder have rarely been studied, which has restricted its application; therefore, this paper studied the hydration mechanisms of a cement–TP composite under different temperatures. In this study, the influence of TP on the hydration properties of cement-based materials under different curing temperatures was investigated by a compressive strength test, X-ray diffraction (XRD), and thermogravimetric and differential thermal analysis (TG–DTA). Our results showed that a high curing temperature effectively promoted the hydration of Portland cement and the pozzolanic reaction degree of TP and improved the mechanical and microstructural properties of cement-based materials. The high temperature was most conducive to the early development of strength. Additionally, different water-to-binder ratios showed different effects on the contribution coefficients of high curing temperatures. The effects of a high temperature on the pozzolanic reaction of TP may lead to greater Ca(OH)2 consumption during hydration. This research provides a new way to improve the reaction activity of TP and lays a theoretical foundation for applying TP to precast concrete products, mass concrete, or concrete construction in hot seasons.

Synthesis, structure, Hirshfeld surface analysis, and computational studies of 2-amino-5-nitropyridine-2,4-dinitrophenol cocrystal

A supramolecular cocrystal of 2-ammino-5-nitropyridine (ANP) with 2,4-dinitrophenol (DNP) has been successfully grown by the slow evaporation solution growth technique. The crystal structure of 2-amino-5-nitropyridine-2,4-dinitrophenol (ANDP) was elucidated by the single-crystal X-ray diffraction analysis, and it belongs to a monoclinic system with centrosymmetric space group P21/n. The bulk phase purity and homogeneity of the material were confirmed by powder X-ray diffraction analysis. The functional groups present in the molecule are identified by FT-IR analysis, and the band gap energy was estimated using diffuse reflectance data by the application of the Kubelka–Munk algorithm. The thermal stability of the compound was investigated by carrying out TG–DTA analysis. Theoretical calculations were performed using the density functional theory method to derive the dipole moment and hyperpolarizability. The high value of first-order molecular hyperpolarizability (β) suggests that it is a potential microlevel NLO candidate.

Influence of Thermal Treatment of Moroccan Red Clay on its Physicochemical and Mechanical Behavior

AbstractRed clay is considered to be of significant value to the economy in Morocco, particularly in the Safi region, because of its abundance. This raw material has long been known for its quality in the manufacture of clay materials, but its use was limited to traditional ceramics. The red clay raw material was the subject of the current study with the objective of opening new industrial applications that will give added value to the Safi red clay. The physicochemical, mineralogical, and thermal properties of the Moroccan red clay were determined by X-ray fluorescence (XRF), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis, X-ray diffraction (XRD), oriented aggregate, and particle-size analyses, powder density by helium pycnometry, carbonate content using the Bernard method, differential thermal analysis (TG–DTA), and the BET surface area. The compacted dry powder particles were calcined at three sintering temperatures: 900, 1000, and 1100°C for 2 h. The effect of sintering temperature on ceramic properties, such as apparent porosity, water adsorption, bulk density, and mechanical strength, was examined. Dense ceramics with lower porosity and greater mechanical resistance (~300%) were produced by increasing the sintering temperature from 900 to 1100°C. The conclusion was that the evolution of physicochemical and thermal properties is related to mineralogical changes, which show that anorthite is the major phase at higher temperatures.

Influence of alumina modulus on formation of high-magnesium clinker and morphological evolution of MgO

This work investigates the influence of alumina modulus (AM) on the formation of high-magnesium clinker (w(MgO) > 5 %) and the morphological evolution of MgO and prepares clinkers with different MgO contents by using analytical reagents. High-temperature microscopy (HTM), thermogravimetric–differential thermal analysis (TG–DTA), X–ray diffraction (XRD), optical microscopy and backscattered electrons–energy–dispersive spectrometry (BSE–EDS) examine the clinkering mechanism. The results show that a reduced AM improves burnability of raw meal and the formation of more regular and larger alite particles. An increased AM contributes to reducing the size of the periclase and causes the shape of its particles to be round. An AM of 1.1 leads to the lowest liquidus temperature and increased tricalcium silicate (C3S) content. In this case, a maximal solid solubility and a minimal crystallinity of MgO can be obtained. The highest content of C3S and tetra-calcium aluminoferrite (C4AF) can be achieved at an MgO content of 3 %–6 %.