Thermogravimetric Differential Thermal Analysis Research Articles

Experimental Study on the Strength and Microstructure of Red Mud-Based Silty Sand Modified with Lime–Fly Ash

This study aimed to assess the viability of utilizing lime–fly ash (LF) and red mud (RM) in the modification of silty soil (LF-RMS) for subgrade filling. The primary objective of this research was to analyze the mechanical characteristics and examine the curing mechanisms associated with said modified materials. Different curing times were utilized in the analysis of mechanical properties (e.g., via unconfined compression testing), microstructure (via scanning electron microscopy, X-ray diffraction, and thermogravimetric-differential thermal analysis), and environmental indices (via assessment of corrosivity, heavy metal concentration, and radioactivity) with various dosages of red mud (DRM) and Lime–fly ash (DLF). Analyses of the curing mechanisms, failure modes, microstructures, and degrees of environmental impact associated with LF-RMS were also undertaken. The tests indicated that the unconfined compressive strength (UCS) exhibited an initial increase followed by a decrease as the DRM and DLF levels increased. Additionally, the strength of LF-RMS increased with an increase in curing time. It is worth noting that the specimen composed of 20% LF and 23% RM (D20%LF+23%RM) demonstrated a maximum UCS value of 4.72 MPa after 90 days of curing, which indicates that it has the strongest ability to resist deformation. The strength of the specimen cured for 90 days was 1.4 times higher than that of the specimen cured for 7 days (1.97 MPa). Furthermore, the toxic concentration and radionuclide index of LF-RMS were significantly reduced compared to those of pure RM. The overall concentration of heavy metals in the D20%LF+23%RM specimen decreased by more than 60% after curing for 28 days. The internal irradiation index and the external irradiation index decreased by 1.63 and 1.69, respectively. The hydration products in LF-RMS play a key role in the solidification of heavy metals, and the alkaline environment provided by RM also contributes to the precipitation and replacement of heavy metals. In this study, red mud, fly ash and lime were used to modify silty soil. The central tenets of sustainable development may be achieved through the reuse of RM as a road filler.

Study of biphasic calcium phosphate (BCP) ceramics of tilapia fish bones by age

Biphasic calcium phosphate (BCP), consisting of bioceramics such as HAp + β-TCP and Ca10(PO4)6(OH)2 + Ca3(PO4)2, is a popular choice for optimizing performance due to its superior biological reabsorption and osseointegration. In this study, BCP was produced by calcining the bones of tilapia fish (Oreochromis niloticus) reared in net cages and slaughtered at an age ranging from 15 to 420 days. The bones were cleaned and dried, calcined at 900 °C for 8 h, and then subjected to high-energy grinding for 3 h to produce BCP powders. After the calcination process, the crystalline phase’s hydroxyapatite (HAp) and/or beta-tricalcium phosphate (β-TCP) were present in the composition of the bioceramic. The age-dependent variation in phase composition was confirmed by complementary vibrational spectroscopy techniques, revealing characteristic peaks and bands of the bioceramic. This variation was marked by an increase in HAp phase and a decrease in β-TCP phase. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) from 25 to 1400 °C showed the characteristic mass losses of the material, with a greater loss observed for younger fish, indicating the complete removal of organic components at temperatures above 600 °C. Comparison of the results obtained by X-Ray Diffraction (XRD) and Rietveld refinement with Raman spectroscopy showed excellent agreement. These results showed that with temperature and environment control and adequate fish feeding, it is possible to achieve the desired amounts of each phase by choosing the ideal age of the fish. This bioceramic enables precise measurement of HAp and β-TCP concentrations and Ca/P molar ratio, suitable for medical orthopedics and dentistry.

Spectral, crystal structure of novel Pyran-2-one Zwitterion Schiff derivative: Thermal, Physicochemical, DFT/HSA-interactions, enol↔imine tautomerization and anticancer activity

A novel Schiff base (SB) derivative, (E)-3-(1-((2,6-diisopropylphenyl)-imino)-ethyl)-4‑hydroxy-6-methyl-2H-pyran-2-one, was synthesized in a high yield through the direct condensation of 2,6-diisopropylaniline with 3-acetyl-4‑hydroxy-6-methyl-2H-pyran-2-one in ethanol under reflux conditions. The synthesized ligand was identified using different elemental analysis (CHN-EA) and spectroscopic techniques (2D-nuclear magnetic resonance (1H- & 13C- NMR), Fourier transform infrared (FT-IR) and mass (MS) spectroscopies), and their structural analysis was performed by single crystal X-ray diffraction (XRD). In addition, the thermogravimetric behavior of the ligand was evaluated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The DFT calculations on the gaseous state and in chloroform as solvent using B3LYP-D3/6–311++G(2d,p) and the HSA calculations were performed to examine the stability of the tautomeric forms of the ligand and to understand its Zwitterionic behaviors. The results showed that the ligand exhibits a zwitterionic form stabilized by an intramolecular single proton transfer process between the enol and imine tautomerism. The enol↔imine tautomerization was determined by XRD and computed by DFT/HSA calculations, which proved the stabilization of the [N+−−H⋯O−−] zwitterionic form via S6 intra-H-bond. In addition, the Colorimetric [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the ligand exhibits high activity against cancer cells, specifically HeLa cells, at low concentrations.

Investigation on structural, optical, thermal, and dielectric properties of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum nanocomposite prepared by pulsed laser ablation

Polymer nanocomposite films of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum (CP/SMAC/Mo) were fabricated by pulsed laser ablation of Mo in the polymer solution for 10, 20, and 30 min. The films were then characterized by various analytical methods. X-ray diffraction (XRD) revealed that the addition of Mo to CP/SMAC removed the crystalline peaks of Mo without changing the amorphous nature of the copolymer. According to the scanning electron microscopy (SEM) and atomic force microscopy (AFM) patterns, Mo atoms were trapped in the amorphous polymer stacks. The energy-dispersive X-ray (EDX) spectrum features C, O, and Mo. FTIR confirmed the embedding of Mo in the polymers. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were carried out on the samples. The pristine polymer film exhibited a band gap energy of 2.9 eV, which decreased to 2.05 eV because of the loading of the Mo nanoparticles. The intensity of the photoluminescence (PL) peak of the films increases with ablation time such that the absorption intensity of the film at a λmax of 426 nm increases by trifold during the 30 min of irradiation, which is consequently due to the increased amount of Mo in the nanostructure. The incorporation of Mo in the polymer matrix enhances the dielectric constant (ε') (6.28–18.13) and ac conductivity (σac) (3.19 × 10−5–1.12 × 10−4 S/cm) of the polymer with negligible dielectric loss. The results suggest possible technological utilization of these materials in such applications as supercapacitors, light-emitting diodes, and organic optoelectronic devices, among others.

Synthesis and characterization of chitosan-based pH-sensitive biofilm: An experimental design approach for release of vitamin B12

Hydrogels because of their unique potentials, such as highwater content and hydrophilicity, are of interest for the controlled release of drug molecules. In the present study, a biofilm was produced using chitosan, a natural polymer. Characterization analyses of the synthesized biofilm were performed using Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis-differential thermal analysis, x-ray diffraction, and scanning electron microscopy-energy dispersive x-ray spectrometry. The analysis results of the film before loading were compared to the analysis made after adding vitamin B12 to the film. The release percentage of vitamin B12 was investigated by using ultraviolet-visible spectrophotometery. The FT-IR bands of vitamin B12 were in the range of 2,800-3,500 cm-1 and 1,000 cm-1-1,750 cm-1. When pH increased from 3 to 7, release of vitamin B12 from the biopolymer increased up to pH 5. While examining the release potential, parameters, such as pH, initial concentration of vitamin B12, release time, and solution volume, were optimized by using response surface methodology. It was determined that with the increase in release time and the initial concentration, pH contributed positively to the release of vitamin B12. The following conditions were determined for release of vitamin B12 from the biofilm: pH: 4.2, initial concentration of vitamin B12: 54.0 mg L-1, the release time: 117 min, and volume of solution: 2.1 mL. The analysis of variance results showed that the determination coefficients for the use of synthesized biofilm in vitamin B12 release were high and R2 =0.9704.

Effect of flame retardants and 1% stabiliser on thermal decomposition and physics properties of thermoplastic polymer due to TGA and DTA tests

This work introduces seven various polymer samples blended in a twin-screw extruder with flame retardants (FR), and an additive, which is a 1% Stabiliser, to investigate thermoplastic polymer melting, thermal decomposition, and melting moderates. The reduction method is used to analyze its melting points, physics and chemical properties, and thermal decomposition. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) tests are known as thermal analysis tests. It was established that halogenated flame retardants have little effect on reducing the rate of gas escape from polymer melt which affects the viscosity, as it was found. Thus, the APP and FR245 in Polymer help in some polymer leftovers. All samples were treated with flame retardants and no clay, melted completely, at the end of the test some samples did change. All these results investigated by (the XRD) test either, Scanning Electron Microscopic (SEM) or Digital images have been used also applied Limiting oxygen index (LOI) test, in the previous work for the same samples of polymers to verify the results and record a more precise outcome to draw the relationship between melting and dripping behavior via the following studies due to the furnace test which is modulated and calibrated. As a result, the addition of clay together with conventional flame retardants enhances the overall thermal stability forming the polymer. The compatibles help in improving the dispersion of the clay in polymer and reduce the rate of gas escape from polymer melt affecting the viscosity.

High-temperature oxidation resistance behavior and mechanism of HfSiO4-modified C/SiC composites

To enhance the oxidation resistance of C/SiC composites, HfSiO4 was introduced into C/SiC composites to modify the matrix utilizing two cyclic alternating preparation modes, thereby yielding the C/SiC-HfSiO4 composites with a composite matrix. Using X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy-dispersive spectrometer (EDS), and thermogravimetric-differential thermal analysis (TG-DTA), a comprehensive investigation was conducted into the oxidation behavior and mechanism of the prepared composites. Results reveal that the C/SiC-HfSiO4 composites prepared using cyclic alternating preparation modes display the reduced oxidation mass loss and enhanced retention of flexural strength, despite of having higher porosity. In short, the introducing of HfSiO4 can effectively improve the oxidation resistance of C/SiC composites. The effects of the matrix particle refinement and the synergy between the HfSiO4 and SiO2 jointly lead to the enhanced oxidation resistance.

Exploring the adsorption potential of lanthanum (III), samarium (III), and cerium (III) from aqueous solutions utilizing activated carbon derived from date seeds

In the present investigation, Lanthanum (III), Samarium (III), and Cerium (III) were subjected to adsorption onto activated carbon derived from date seeds (ACDS), which underwent activation using 40 % sulfuric acid. The activated carbon (ACDS) was characterized through X-ray Diffraction (XRD), Thermogravimetric Analysis-Differential Thermal Analysis (TG-DTA), and Fourier Transform Infrared Spectroscopy (FTIR). Thermodynamic parameters were calculated to assess the sorption process, revealing an endothermic and spontaneous nature, accompanied by an increase in system randomness. The findings showed that when the pH rose to an ideal level of 5.7 and the contact duration was extended to 180 min, the number of cerium (III) and samarium (III) ions absorbed increased. the distribution coefficient (Kd) of La(III) from 22.22 to 1000 mL/g, Ce(III) from 28.07 to 1865.38 mL/g, and Sm(III) from 35.71 to 3971.43 mL/g, with the pH varying from 1.2 to 5.7. The Langmuir model exhibited superior fitting to the experimental data compared to the Freundlich model, suggesting homogeneous adsorption on the ACDS surface. The maximum adsorption capacities (Qmax) for La3+, Ce3+, and Sm3+ onto ACDS were determined as 18.18 mg/g, 24.58 mg/g, and 27.82 mg/g, respectively.

Single crystal of barium bis para-nitrophenolate para-nitrophenol tetrahydrate for NLO applications: crystal growth and DFT analysis

Abstract Single crystals of barium bis para-Nitrophenolate para-Nitrophenol tetrahydrate (BBPNT) were grown via the slow evaporation technique. The crystal dimensions were measured to be 15 mm × 10 mm × 6 mm. The BBPNT crystal was analyzed using X-ray diffraction, FTIR spectrum, UV–vis spectrum, dielectric studies, thermo-gravimetric (TG) differential thermal analyses (DTA), Vickers microhardness test, second-harmonic generation efficiency, Z-scan technique, PL spectra, and laser damage threshold studies. These findings were previously published in our paper. In the current situation, the theoretical methods include analyzing several aspects, such as the molecular structure determined using X-ray experimentation at its lowest energy state. This analysis is then contrasted by means of density functional theory (DFT) with a suitable set of basic functions. The first-order hyperpolarizability may also be determined via the use of Density Functional Theory (DFT) methods. The molecule’s stability, resulting from hyper conjugative interactions, was examined using the natural bond orbital approach to analyses its nonlinear optical activity and charge delocalization. The magnitude of the HOMO–LUMO energy gap indicates the potential for charge transfer inside the molecule. The investigation of donor-acceptor interactions was conducted using NBO analysis based on optimized ground state geometries.

Physical and chemical techniques for a comprehensive characterization of river sediment: A case of study, the Moquegua River, Peru

River sediment is comprised of complex mineral systems composed by different kinds of organic and inorganic matter, and thus, is difficult to characterize. Besides, some standard techniques, such as X-ray diffraction (XRD), energy dispersive X-ray (EDX), optical and scanning electron microscopy, Fourier transmission infrared spectroscopy, inductively couple plasma-mass spectrometry (ICP-MS), and simultaneous Thermogravimetric Analysis – Differential Thermal Analysis (TGA-DTA), Mössbauer spectroscopy and magnetometry can provide substancial information about the compositional, physical, and chemical characteristics. In the current study, the versality of these methods is tested and the information provided by these methods for eight sediment samples, collected from the Moquegua River, Peru is compared. Qualitative analysis indicates that the samples consist of sand grains with different shapes, sizes, and colors coexisting with the presence of some diatoms. The chemical and mineralogical analysis reveal that the samples are composed mainly of silicon (Si), aluminium (Al), sodium (Na), potassium (K), aluminon–silicates, and carbonates, typical for river sediment. More detailed information obtained by these techniques include the discovery of adsorbed oxygen–hydrogen (O–H), carbon–H (C–H) and C, from organic matter, the thermal reactions and decomposition of the components, and the identification of the minor iron–oxides components. Further, other properties such as magnetic interaction are also analyzed in detail.

Application of a Bio-waste Einkorn (Triticum monococcum L.) Husks Adsorbent for Removal of Metanil Yellow and Methylene Blue from Aqueous Media with Equilibrium, Kinetic, and Thermodynamic Studies

In this study, the activated carbon (TmAC) with a high surface area and appropriate pore distribution was produced from einkorn (Triticum monococcum L.) husks by using ZnCl2 with chemical activation method. The efficiency of the obtained activated carbon on the adsorption of anionic (metanil yellow) and cationic (methylene blue) dyestuffs from aqueous solutions was investigated in more detail. In addition, the surface characterization of activated carbon was performed using thermogravimetric analysis-differential thermal analysis (TGA-DTA), elemental analysis, scanning electron microscopy (SEM) images, Brunauer–Emmett–Teller (BET) specific surface areas, N2 adsorption–desorption isotherms, pore volumes, pore size distributions, and Fourier-transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) spectra. The highest surface area of activated carbon was measured as 1321 m2 g−1 at the carbonization temperature of 500 °C by using impregnation ratio (w/w = 2.0). Batch method was used in adsorption experiments. The parameters affecting the adsorption studies such as adsorbent concentration, initial dye concentration, adsorption time, temperature, and pH were investigated. The adsorption mechanisms of metanil yellow (MY) and methylene blue (MB) on activated carbon were explained by using isotherms (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich), kinetic models (pseudo-first-order and pseudo-second-order), and the thermodynamic parameters (Gibbs free energy, enthalpy, and entropy).Graphical

Isolation and Characterization of a Novel Crystalline Pigment as a Natural Colorant

This research focuses on the isolation and thorough characterization of a distinctive pigment-producing bacterial strain, ACFM05, obtained from Daucus carota subsp. Sativus (Carrots). The pigment was systematically examined for morphological, microscopic, biochemical, and molecular features, utilizing 16S rRNA sequencing. The strain was identified as a novel species within the Micrococcus genus, specifically classified as Micrococcus yunnanensis. The optimization of pigment extraction parameters revealed a pH of 8 at 40 °C as the ideal conditions for maximum yield. UV studies indicated that the pigment, extracted with methanol as the solvent, exhibited a notable absorption peak at 445 nm, closely resembling the absorption peak of carotenoids. The growth biomass of the bacteria was found to be influenced by the antioxidant activity, reducing power assay, and total phenolic content. The pigment extracts were further evaluated for their antifungal, antibiotic sensitivity, and antibacterial activities against Pseudomonas, Staphylococcus aureus, and Escherichia coli. Results indicated significant potential for the pigment as an antimicrobial agent. To elucidate the molecular and structural characteristics of the pigment, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric-differential thermal analysis (TG-DTA), and scanning electron microscopy (SEM) analyses were employed. The findings from these analyses collectively confirmed the presence of carotenoids in the bacterial pigment. Furthermore, XRD studies revealed the crystalline nature of the pigment. In conclusion, the unique crystalline pigment isolated from Micrococcus yunnanensis ACFM05 demonstrates promising potential as a natural colorant for food applications. This study contributes valuable insights into the microbial production of pigments with multifaceted applications in the food industry.

Development of a sprayable PVA-fiber-enhanced cement mortar with high acid-corrosion resistance for pipeline rehabilitate

The spraying method offers the advantages of environmental protection, convenient construction, and cost-effectiveness, making it widely used in pipeline structure repair. Given the complex service environment of pipelines, there is an urgent demand for high-strength and durable spraying materials. To achieve this goal, a PVA fiber reinforced cement mortar material (PFCM) with high early strength, excellent impermeability and stable acid corrosion resistance was developed through orthogonal test design. The optimal material was obtained through factors such as setting time, fluidity, compressive strength and flexural strength. The effects of the contents of fly ash, redispersible polymer powder and PVA fiber on the working and mechanical properties of the material were investigated, and further research was conducted on its tensile strength, impermeability, acid corrosion resistance. In addition, Thermogravimetric-differential Thermal Analysis (TG-DTA) was utilized to analyze the thermal stability of PFCM. X-ray diffraction (XRD) was utilized to analyze the composition of PFCM. Mercury intrusion porosimetry (MIP) was utilized to analyze the pore structure of PFCM, and the feasibility of the PFCM was verified. The results indicate that the contents of fly ash, redispersible polymer powder and PVA fiber have significant effects on the working and mechanical properties. The optimum initial setting time is 60–80 min, and the optimum fluidity is between 170 and 180 mm. The compressive strength and flexural strength of the mortar prepared with the optimum parameters are 102.5 MPa and 20 MPa, respectively. The material has an excellent spraying effect with no sagging, and exhibits high early strength, outstanding corrosion resistance, low porosity, and exceptional impermeability. This study lays the foundation for achieving high-quality spray repairs of underground drainage pipelines.

Insights into ancient ceramic technology: a comprehensive analysis of mineralogy, chemistry and firing conditions

The intensive integration of Azerbaijan into the global economy, mainly through international gas and oil pipeline construction, has led to significant archaeological research in the past two decades. The construction of the Baku-Tbilisi-Ceyhan oil pipeline (BTC) and the Southern Caucasus Pipeline gas pipeline (SCP) prompted a four-year archaeological fieldwork program, followed by a six-year post-excavation program. The current work applied an interdisciplinary approach using various instrumental methods for studying ancient artifacts found during those projects. The thermogravimetric method and differential thermal analysis were employed to obtain insights into the production technology of the ancient pottery and information about the mineralogy of the ceramic sherds. The complex processes involved in firing the ceramic paste have been studied extensively, and patterns in mass loss ratios during different temperature ranges have been established. In total, 15 samples were investigated, and the thermogravimetric analysis of ceramic shards revealed that the firing temperature of the samples was in the range of 700 °C. XRD analysis confirmed the presence of quartz, feldspar, and clay minerals in the ceramic samples. The presence of calcite and other specific minerals is subject to the origin of the ceramic materials. The results obtained from this multidisciplinary approach provide insights into the firing technology and the origin of the ceramic samples.

GO@dopamine-Cu as a Green Nanocatalyst for the Efficient Synthesis of Fully Substituted Dihydrofuran-2(5H)-ones

A new nanocatalyst graphene oxide@dopamine-Cu was synthesized, and its structure was characterized by fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDX), and thermogravimetric analysis – differential thermal analysis (TGA-DTA) techniques. The three-component one-pot reaction between an arylamine, aromatic aldehyde, and acetylenic carboxylate was achieved and formed methyl 5-oxo-2-aryl-4-(arylamino)-2,5-dihydrofuran-3-carboxylate derivatives (4) in the presence of the catalytic amount of graphene oxide@dopamine-Cu nanocatalyst in high yield. Molecular structures of products were characterized by FT-IR, 1H, 13C nuclear magnetic resonance (NMR), and Mass spectroscopy techniques. Representatively, the mass fragmentation of 4a was discussed, and the structure was confirmed. Easy reaction, high performance, and easy catalyst recyclability are the main advantages of this work. This nanocatalyst is recycled up to five successive runs.

Effects of rock water with different acidity on microstructure and reburning ability of residual coal in goaf

To explore the influences of rock water acidity (PH = 4,5,7) over the microstructure and reburning behaviors of oxidized residual coal in the overlying goaf, the pore morphology, coal surface, functional group content and activity of pre-oxidized coal (O0) and water-immersed oxidized coal (OI) were analyzed by Low-temperature nitrogen adsorption and In-situ diffuse reflection experiments, combining with fractal dimension theory and functional group oxidation kinetics. The oxidation and reburning ability of coal samples has been analyzed by Thermogravimetric-Differential thermal analysis experiment. The results are as follows: Part of the type-III pores of pre-oxidized coal become type-II pores when immersed. The acidic solution has stronger corrosivity to O0 than distilled water, playing a role in smoothing coal and improving the uniformity of pore structure. The order of reburning ability of samples is OI7>OI4>O0>OI5 according to the ignition and stage average mass loss rate (RM). The reactivity of –OH may affect the reburning ability of coal more than its initial content. Soaking is beneficial to the decrease of activation energy of aliphatic groups, and the activity of –C=O- and -C-O- in acid-soaked coal molecules is stronger, so that they can take part in coal-oxygen composite reactions at low temperature.

Characterization and properties of Chinese red clay for use as ceramic and construction materials.

This study involves the characterization and analysis of a Chinese red clay obtained from Hunan province to determine its suitability for manufacturing ceramic products. X-ray fluorescence analysis showed the clay has high silica (63.25 weight percent) and alumina (21.38 weight percent) content along with iron oxide, alkalis, and calcium acting as fluxes. X-ray diffraction (XRD) confirmed the presence of quartz, kaolinite, illite, and hematite as the major mineralogical phases. Scanning electron microscopy revealed loosely stacked, plate-shaped kaolinite particles exhibiting pseudohexagonal morphology. Particle size distribution shows a d50 of 12.7 μm and specific surface area is 21.3 m2/g. Differential thermal analysis-thermogravimetric analysis showed mass losses between 450-600°C and 950-1050°C corresponding to dehydroxylation and formation of a liquid phase, respectively. Dilatometry traced the onset of viscous flow sintering around 1000°C. Test bars produced from the clay were fired at 800°C, 900°C, 950°C, 1000°C, and 1050°C. The firing shrinkage increased from 2.5% at 800°C to 12.8% at 1050°C. Strength improved from 11.2 megapascals at 800°C to 42.3 megapascals at 1050°C due to densification and mullite formation. Hematite content caused the color to change from orange-red at 950°C to dark red at 1050°C. XRD analysis of fired specimens confirmed the presence of hematite and newly formed mullite and cristobalite phases. The results indicate the suitability of the clay for manufacturing bricks, roof tiles, and wall tiles using appropriate firing temperatures and cycles.

WASTE EGGSHELLS AS CATALYSTS: AN ENVIRONMENTALLY-FRIENDLY APPROACH

Sustainability is crucial for the survival of mankind, ecosystem for the development of society. There have been huge amount of waste have been dumped which creates pollutions. Hence, from Green chemistry perspective it is a protocol to design heterogeneous catalysts which can yield products from waste products with minimization of wastes pollution with environmentally friendly heterogeneous catalytic process for the developed environmentally friendly products with longevity. Such green synthesized heterogeneous catalysts will replace the existing homogeneous process to heterogeneous catalysts being developed from waste materials. This abstract highlight key aspects on the preparation of heterogeneous catalysts derived from waste materials such as egg shell, rice husk for synthesis of Ag Nanoparticles developed, which can applied for biomass conversions, to environmental remediation, heterogeneous catalysts for organic transformations. These egg shell CaO catalysts are characterized using analytical techniques, such as: X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Thermogravimetric-Differential Thermal Analyzer (TG-DTA), Scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area, which gives its complete picture of its structure, porosity, morphology, thermal stability, reusability, and activity of catalysts. Hence heterogeneous catalysts developed from egg shell wastes and medical plants will become increasingly popular since two decades. Since, the egg shell waste is developed into egg shell CaO catalysts for cleaner, reusable, eco-friendly catalysts for economic growth for Namibia and other developing and underdeveloped countries.

Cetyl alcohol surface functionalization: a strategy for modulating electronic characteristics of boron nitride nanosheets

Hexagonal boron nitride (h-BN) is a two-dimensional material with a unique layered structure akin to Graphene. Cetyl alcohol (CH₃(CH₂)₁₅OH) denoted as CA, a fatty alcohol derived from natural sources like palm oil and coconut oil, holds a significant place in various industries due to its versatile properties. Cetyl alcohol's has a potential in forming stable nanostructures and its interactions with other compounds, shedding light on its utility in nanotechnology and materials science. In this work exfoliation of BNNS and subsequent functionalization using Cetyl alcohol is investigated. The functionalization of boron nitride nanosheets (BNNS) using CA is investigated in this study. The modification process aims to enhance the properties and applications of BNNS. OH groups are functionalized and bring about beneficial changes to its properties, enabling enhanced interactions with other compounds. This modification can lead to improved solubility, emulsification, and lubrication capabilities, expanding its utility in various applications such as cosmetics, pharmaceuticals, and industrial processes. Characterization techniques, including Thermogravimetric analysis(TG/DTA), UV-Visible spectroscopy, Photoluminescence, X- ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) are employed to analyze the efficacy of the functionalization process. Thermogravimetric-differential thermal analysis (TG-DTA) was utilized to investigate the thermal characteristics of the functionalized samples.

Thermochemical Properties of Synthesized Urea from Recovered Ammonia and Carbon Dioxide in Well-Ordered Nanospaces of Hollow Silica Spheres.

The present work investigated the thermochemical properties of urea synthesized in well-ordered nanospaces of porous hollow silica spheres' shells from recovered ammonia and carbon dioxide in aqueous solution. Thermochemical behaviors of the urea synthesized in well-ordered nanospaces of the hollow spheres' shells prepared with 1-dodeclyamine were analyzed from the results of thermogravimetric analysis (TGA) and differential thermal analysis (DTA), and endothermic peaks assigned as the phase transition and decomposition were observed at ca. 440 and 514 K, respectively, which were higher than those of pristine urea (405 and 408 K, respectively), probably because of the nanoconfinement effect. The decomposition behavior was also confirmed by the result of diffuse reflectance infrared Fourier transform (DRIFT) spectra of the samples treated at various temperatures up to 573 K, and the decomposition of urea synthesized in the well-ordered nanospaces of the hollow spheres' shells started at 468 K and completed up to 533 K.