Thermogravimetric And Differential Thermal Analysis Research Articles

Synthesis, characterization and biological studies of transition metal complexes of dehydroacetic acid Schiff bases derived from 3-aminomethyl pyridine

The solid metal complexes of Cu (II), Ni (II), Fe (III), Co (II), Mn (II) and Cd (II) with DHA Schiff base ligand derived from DHA and aromatic primary amine 3-aminomethyl pyridine were synthesized and characterized by elemental analysis, spectroscopic techniques (FTIR, UV-VIS, 1HNMR and XRD), magnetic susceptibility measurement, thermogravimetric analysis and differential thermal analysis (TGA/DTA) and investigated for biological activities like anti-bacterial, ant-fungal, antioxidant and anticancer activity. The structure of synthesized DHA Schiff base ligand and all metal complexes were confirmed by spectroscopic methods, stability of complexes was studied by TGA/DTA. DHA Schiff base ligand and all metal complexes were found to be biologically active.

Structural Properties of Cs<sup>1+</sup> Doped H<sub>3</sub>PMo<sub>12</sub>O<sub>40</sub> Nanocrystalline Polyoxometalate Thin Films

The microwave assisted chemical bath deposition (MA-CBD) technique were used to deposite nanocrystalline thin films of polyoxometalates like phosphomolybdic acid (PMA) (H3PMo12O40) and Cesium (Cs+) doped phosphomolybdic acid (Cs-PMA) (Cs3-PMo12O40). Thermo gravimetric and Differential thermal analysis (TGDTA), Fourier transform infrared spectroscopy (FTIR), Energy dispersive X-ray analysis (EDAX), X-ray diffractometry (XRD) and Scanning electron microscopy (SEM) tools are used for the thermal, structural, morphological and compositional analysis of microwave treated H3PMo12O40 and Cs3- PMo12O40 thin films. The completion of decomposition process at 600 oC of Cs3-PMo12O40 compound is confirmed from TGDTA analysis. The polycrystalline spinel cubic crystal structure of H3PMo12O40 and Cs3-PMo12O40 thin films were confirmed from X-ray diffractometer. The crystallite size of H3PMo12O40 and Cs3-PMo12O40 compound found to be in the range of 50 - 53 nm. The formation of H3PMo12O40 and Cs3-PMo12O40 materials were confirmed from the presence of main four absorption peaks observed in the range from 800 cm-1 to 1100 cm-1. The SEM microphotographs analysis identify the microwave assisted H3PMo12O40 and Cs3-PMo12O40 films have spherical shaped porous nanocrystalline morphology. The grain size of H3PMo12O40 and Cs3-PMo12O40 synthesized material found to be in the range of 10 - 12 A˚ The stoichiometric preparation of H3PMo12O40 and Cs3-PMo12O40 thin films with presence of P, Mo, O and Cs peaks of metal ions is observed from EDAX spectra.

Transformative Nanosized Organic Coatings with Euphorbia Condylocarpa/Poplar Tree Bark/Zircon Silicate Hybrid System for Enhanced Industrial Resilience

This study focused on enhancing the properties of interior coatings by incorporating natural additives to minimize potential health impacts associated with traditional additives. Organic additives such as Euphorbia condylocarpa, poplar tree bark, and zircon silicate were employed by utilizing Design Expert for optimization. The optimized formulation demonstrated impressive attributes including the prevention of bacterial and mold growth, high corrosion resistance, effective coverage and adhesion, and resistance to dirt retention. The recommended optimum formulation, Euphorbia condylocarpa (1%), poplar tree bark (1%), and zircon silicate (1%) by using the 2FI model, exhibited an R2 value of 0.9838, indicating a remarkable predictability of the variability in the experimental data. This result emphasized the effectiveness of the proposed model in optimizing the properties of nanosized organic coatings for various industrial applications. Thermogravimetric and differential thermal analysis (TG-DTA) revealed that the additives contributed to the development of flame-retardant properties as the temperature increased and morphology of coating was obtained with optical microscope and scanning electron microscope (SEM). Specifically, Euphorbia condylocarpa exhibited antibacterial, flame-retardant, and hydrophobic properties. The study concluded that the incorporation of euphorbia plant, poplar tree bark, and zircon silicate substances positively impacted the performance of coatings offering a more health-conscious and technologically advanced alternative.

Three new complexes of Zn(II) with a quinoline based Schiff base ligand: Syntheses, crystal architectures, Hirshfeld surface analyses, DFT study, photoluminescence and thermal properties

This report deals with one dinuclear and two mononuclear zinc(II) complexes of compositions [Zn2L2(μ1,1-N3)(N3)] (1), [ZnL(NCO)(H2O)] (2) and [ZnL(NCS)(H2O)] (3), where HL ((E)-2-ethoxy-6-((quinolin-8-ylimino)methyl)phenol)) is the 1:1 condensation product of 3-ethoxysalicylaldehyde and 8-aminoquinoline. All the three metal complexes have been characterized by C, H, N elemental analyses, FT-IR spectra, single crystal X-ray structures and powder XRD. The structures of 2 and 3 are isomorphous. The metal centres in 1–3 are five coordinated and adopt vacant octahedral or distorted square pyramidal geometry for 1 and distorted trigonal bipyramidal geometry for 2 and 3. Supramolecular interactions and topologies in all the three crystal structures have been analyzed, revealing 3–D assemblies in 1–3 due to a number of non-covalent interactions (C–H···O, C–H···N and π···π in 1; C–H···O, O–H···O, O–H···N, π···π and C–H···π in 2; C–H···S, O–H···O, O–H···N, π···π and C–H···π in 3). To gain additional insight into the intermolecular contacts and their relative contributions towards the packing, Hirshfeld surface analyses have been undertaken for 1–3 and demonstrated in detail with respect to structural parameters, depressions in surfaces, fingerprint plots and enrichment ratios. The thermo-gravimetric and differential thermal analyses (TG/DTA) have been performed and the decomposition patterns are well explained. Steady state and time resolved fluorescence properties have been investigated. Optical band gaps have been determined from the data of the UV–Vis spectra. DFT calculations have been undertaken. The DFT computed HOMO-LUMO gaps corroborate the optical gaps and the DFT computed electrostatic potential (ESP) surfaces rationalize the supramolecular interactions nicely.

Acidic pathway in formation of SiO2–AlO2–PO2 geopolymeric ceramic: Investigation of structural evolution and electrical behaviour

The investigation into the acidic pathway in geopolymer formation has been overlooked compared to the alkaline pathway. This study seeks to fill the gap by exploring the development mechanism and electrical properties of this type of geopolymer. The microstructural properties of geopolymer ceramics were assessed through the deconvolution of attenuated total reflectance-Fourier-transform infrared spectra (ATR-FTIR), powder X-ray diffraction (PXRD), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), simultaneous thermogravimetric analysis and differential thermal analysis (TGA/DTA). Furthermore, the electrical properties of the prepared ceramics were monitored using solid-state impedance spectroscopy (ss-IS). Maintaining an Al to P molar ratio of 1:1, various post-treatment temperatures (60 °C, 105 °C, 300 °C, 1200 °C) were employed to observe their effects on the (micro)structural properties of the samples under investigation. This ratio ensures the formation of an amorphous structure of SiO2·Al2O3·P2O5·nH2O. Additionally, the emergence of new crystalline aluminium and phosphate phases was observed.

Tuning thermal and structural properties of nano‐filled PDMS elastomer

AbstractIncreasing the thermal stability and thermal conductivity of polydimethylsiloxane (PDMS) is a crucial issue for thermal applications. This paper focuses on enhancing PDMS's thermal and structural properties by incorporating nanocomposite into the PDMS matrix. An investigation of the impact of rGO‐CaCO3 nanocomposite on the thermal and structural properties of PDMS was performed using Field Emission Scanning Electron Microscopy (FESEM), X‐ray diffraction (XRD), the thermogravimetric analysis and differential thermal analysis (TGA‐DTA), and thermal analyzer tests. It was observed that PDMS doped with rGO‐CaCO3 nanocomposite shows better thermal stability, thermal conductivity, and higher crystallinity. The thermal stability was enhanced significantly by adding a 5% rGO‐CaCO3 nanocomposite, and the initial and end degradation temperatures rose to 492°C and 605°C, respectively. The thermal conductivity of pure PDMS is approximately 0.17 W/mK, whereas a conductive elastomer filled with 5% rGO‐CaCO3 nanocomposite exhibits a thermal conductivity of 0.44 W/mK at a temperature of 20°C. In contrast, the thermal diffusivity is enhanced from 0.13 mm2/s to 0.366 mm2/s. Additionally, the Fourier Transform Infra‐Red (FTIR) spectrum at 1411 cm−1 becomes sharp and noisy, and an additional peak arises at 1398 cm−1, corresponding to the vibrational rocking of the CC bond and COC bond in CaCO3 and rGO.Highlights The manuscript focuses on the development of conductive elastomer by incorporating rGO‐CaCO3 doped and its effect on the morphology, structure, and thermal properties of PDMS. The variation in peak intensity observed in XRD attributed to disparities in the crystalline structure of PDMS due to the inclusion of nanocomposite. The thermal degradation range is observed to shift toward the upper end. The degradation temperature at the beginning and end of the process is observed to move to 492°C and 605°C, respectively, upon introducing a 5% rGO‐CaCO3 nanocomposite. The addition of 5% rGO‐CaCO3 filled conductive elastomers shows a significant improvement of approximately 2.6 times in heat conductivity than bare PDMS.

The Complex of Cr(III) with Ligand of 2,6-Bis(pyrazol-3-yl)pyridine and Anionic Trifluoromethanesulfonate: Synthesis, Characterization and Antibacterial Activity

The complex containing chromium(III), 2,6-bis(pyrazol-3-yl)pyridine (3-bpp), and CF3SO3– (trifluoromethanesulfonate (triflate)) has been prepared and characterized. The conductance, metal content, and thermogravimetric and differential thermal analysis (TGA-DTA) analysis suggest the complex to be [Cr(3-bpp)2](CF3SO3)3.2H2O. The paramagnetic moment corresponds to the three unpaired electrons being consistent with the electronic configuration of chromium(III). The electronic spectral bands are not well resolved attributed to the spin-allowed transitions of quartet ground state to quartet excited states. The IR spectral data signify the mode of vibrations typical for 3-bpp as well as the triflate. While the images of scanning electron microscope-energy dispersive X-ray (SEM) photographs confirm the crystalline particle size and the energy dispersive X-ray (EDX) signifies the existence of all elemental content. The analysis of powder-X-ray diffraction (powder-XRD) following the Rietica program of Le Bail suggests being a structurally orthorhombic crystal system, and Pbca space group, with Z = 16, Rp = 4.30, Rwp = 5.14, Rexp = 12.17, R-FBragg = 0.04, and goodness of fitting (GOF) = 0.1783. The complex shows a weak inhibition of bacterial activity against S. aureus and E. coli.

Assessment of select direct and indirect pozzolanic reactivity test outcomes with robust regression and ranking analysis

The use of pozzolanic materials as a sustainable partial replacement option for portland cement in concrete has been extensively studied over the last few decades. This study aimed to assess the pozzolanic reactivity of seven different powdered materials: pottery cull, brick powder, lightweight aggregate fines, class C fly ash, silica fume, glass powder, and dolostone. Pozzolanic reactivity was evaluated using seven different direct and indirect methods, including the Frattini test, strength activity index (SAI), ultrasound pulse velocity index (UPVI), thermogravimetric and differential thermal analyses (TG/DTA), calorimetry, electrical conductivity, and pH. Robust correlations and a ranking analysis were performed to evaluate the relationship and efficiency between various direct and indirect test methods. Results of the robust regression analyses showed that Frattini and TGA, SAI and electrical conductivity, SAI and calorimetry, and UPVI and calorimetry were well correlated, suggesting that these methods may be suitable alternatives to each other. According to the ranking method, electrical conductivity and calorimetry are the most rapid and efficient methods for the assessment of different pozzolans in comparison to other longer-duration test methods examined in this study.

Er3+ ion-doped Mg-Zn nanoferrite: Properties and applications in dielectric, magnetic, structural, and optical domains affected by calcination temperature

A series of Mg-Zn ferrites with Er3+ion doping in the shape of cubic spinel were produced using the citrate sol–gel auto-combustion process known as Mg0.5Zn0.5Er0.1Fe1.9O4 (MZE) (calculated at 400, 550, 700, 850, and 1000 °C), and the same was confirmed with the XRD diffractograms. It was possible to understand the presence of hydrated water, which degrades behavior. Hence, the powders created were sintered at various temperatures for four hours. After that, it was observed that the cubic spinel phase was free of impurities. The as-prepared spinel Mg-Zn ferrite nanoparticles also showed a specified behaviour, according to the results. The SEM, UV–Vis spectroscopy, FT-IR (Fourier transform infrared) spectroscopy, TG-DTA (thermogravimetric and differential thermal analysis), XRD (X-ray diffractometer), LCR metre, and VSM (vibrating sample magnetometer) were the characterization techniques used to examine the samples' structural, optical, dielectric, and magnetic properties. A microstructure investigation was done using FESEM analysis. Based on these FESEM measurements, the nanoparticles' sphere-shaped structure was confirmed. FT-IR spectroscopy has been employed to examine the chemical bonds in the spinel ferrite. There is evidence of a shift in bands ν1 and ν2. The produced materials' semiconducting qualities are demonstrated by the optical band gap energy, which is in the range of 1.648–1.798 eV. Variation of dielectric parameters with Er doping was measured in the frequency range from 100 Hz to 1 MHz at room temperature (RT) and at temperatures of 100–400 °C. These results were very well supported by Maxwell-Wagner interfacial polarization. The dielectric properties were observed to decrease with an increase in frequency due to calcinated MZE samples. The magnetic properties of ferrite nanoparticles were investigated in detail at 300 K and 5 K. Early signs of superparamagnetic behaviour have been observed in the prepared sample. It is used in industries like nanoelectronic devices, detectors, imaging devices, super-paramagnetic coils, and magnets.

Thermo-kinetics study of microalgal biomass in oxidative torrefaction followed by machine learning regression and classification approaches

Solid biofuels derived from microalgae represent a low-cost, high-volume bioproduct opportunity with excellent CO2 biofixation capability, contributing significantly to the attainment of net zero. Oxidative torrefaction also offers a more economical pretreatment to upgrade its solid fuel properties. This study investigates the thermo-kinetics aspect of oxidative torrefaction of microalgae with varying O2 concentrations using thermogravimetric and differential thermal analysis (TGA-DTA). Isoconversional kinetic modeling is applied to mass-loss data and shows average activation energies of 172.57, 174.68, 199.42, and 209.03 kJ‧mol−1 at 0, 3, 12, and 21 % O2 concentrations, respectively. The effect of O2, especially at 12 vol%, significantly reduces the calculated activation energy at lower conversion. DTA also reveals lower heat flow values under oxidative than inert torrefaction. Thermo-kinetics data are then utilized to conduct machine learning approaches. Regression via artificial neural networks shows that the prediction of conversion and heat flow values are predominantly dictated by the temperature, followed by heating rate and O2 concentration. Finally, classification using the k-nearest neighbors algorithm highlights the effects of factors at specific ranges of conversion and heat flow responses. The O2 concentration is significant only at early conversion (X<0.1) and contributes to generally lower heat flow values.

Study on mechanical performance and mesoscopic simulation of nano-SiO2 modified recycled aggregate concrete

Utilizing nano-SiO2 (NS) to reinforce the old mortar and the weak interfacial transition zone (ITZ) in recycled coarse aggregate (RCA) is a productive approach to enhance the quality of RCA. Throughout this paper, RCA was immersed in NS solutions with different concentrations (2, 5, 10 and 30 wt%). Subsequently, a systematic evaluation of the crushing index and water absorption of the treated NS modified recycled coarse aggregate (SRCA) was conducted. In addition, the calcium hydroxide (CH) content of RCA before and after modification was analyzed by Thermogravimetric and Differential Thermal Analysis (TG-DTA) curves. This study finds that the performance of SRCA modified with 2% concentration achieves comparable modification effects to other concentrations. Additionally, this paper delves into the impact of NS powder on the slump characteristics and compressive strength of concrete. Considering the above research and economic costs, this study adopts 2% concentration of NS for RCA modification and further investigates the stress-strain relationship of NS modified recycled aggregate concrete (SRAC) with various SRCA replacement ratios. Moreover, this paper establishes mesoscopic models of SRAC for various replacement rates and proposes constitutive models corresponding to these rates. The results indicate that when the SRCA replacement rate is within 60%, the stress-strain curve shape of SRAC closely resembles that of natural aggregate concrete (NAC); when the replacement rate exceeds 60%, the descending segment of the SRAC stress-strain curve becomes more precipitous, showing a higher tendency towards fragility in the concrete.

Synthesis and characterization of porous and photocatalytic geopolymers based on natural clay: Enhanced properties and efficient Rhodamine B decomposition

In this work, the incorporation of anatase TiO2 semiconductor in the geopolymer matrix as catalytic materials has been studied. The most noteworthy results obtained from the synthesis of a novel TiO2/geopolymer nanocomposite as an effective ecological catalyst with high thermal stability and significant porosity is presented. The porous and photocatalytic geopolymers based natural clay rich in pyrophyllite and kaolinite minerals were prepared by simple method, the geopolymerization reaction was able to successfully load TiO2 nanoparticles into the geopolymer surface. Furthermore, the results indicate that the prepared catalyst achieved the best performance to degrade Rhodamine B (RhB) molecules present in aqueous solution under UV light irradiation. The geopolymer matrix proved to be a reusable support for TiO2 nanoparticles during the photocatalytic process, efficiently facilitating the separation of photogenerated charges. Finally, the physicochemical and morphological properties of the samples was characterized by several techniques, namely X-ray Fluorescence (XRF), X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Thermogravimetric and Differential Thermal Analysis (TGA/DTA), N2 adsorption/desorption isotherm analysis (BET and BJH methods), UV–Vis Diffuse Reflectance Spectroscopy (DRS), Scanning Electron Microscopy (SEM) coupled to an Energy Dispersive X-ray Spectroscopy (EDS) analyzer and Transmission Electron Microscopy (TEM).

Impact of cation distribution on structural, morphological, optical and low-temperature magnetic properties of Er3+ substituted Cu0.8Cd0.2Fe2O4 nanoparticles

A series of cubic spinel-shaped Cu-Cd ferrites using Er3+ ion doping, Cu0.8Cd0.2ErxFe2-xO4 (x = 000, 0.0010, 0.0015, 0.0020, 0.0025, and 0.0030-CCEF) had been synthesized using the citrate sol-gel auto combustion approach. The structural, optical and magnetic properties of the samples were investigated using a wide range of characterization techniques, such as Thermogravimetric and Differential thermal analysis (TG-DTA), Powder x-ray diffractometer (P-XRD), High-resolution transmission electron microscopy (HR-TEM), UV–VIS, Electron spin resonance (ESR), and Vibrating sample magnetometer (VSM). To obtain an understanding of the existence of hydrated water and comprehend the degradation behavior, the TG-DTA was carried out. The produced powders were then sintered for 240 min at 500 °C. According to X-ray diffraction spectra, the John-Teller ion (Cu2+) causes a tetrahedral deformation for pure Cu-Cd ferrite. Erbium substituted afterwards transformed the tetragonal phase towards the cubic spinel phase including trace amounts of impurity phase. FESEM and HRTEM analysis were employed to investigate the microstructure. These FESEM and HRTEM images' observations demonstrated that nanoparticles have a spherical shape. Furthermore, the findings showed that the as-prepared spinel Cu-Cd ferrite nanoparticles exhibited a determined optical band gap energy in the region of 1.62–1.91 eV, demonstrating the semiconducting properties of the synthesized materials. In order to calculate the spin resonance parameters such as the g-values, peak-to-peak linewidth and resonance field, ESR spectra accumulated with X-band microwave energy have been fitted using the Lorentzian function. At 15 K, an in-depth examination of the ferrite nanoparticles' magnetic characteristics was performed. The prepared sample has shown indications of developing superparamagnetic behavior.

Selective Crystallization of Linkage Isomers, [RhIII(NCS)(SCN)5]3- and [RhIII(SCN)6]3-, to Investigate Structural Trans Influence and Thermal Stability.

Linkage isomers of homoleptic complexes, [RhIII(SCN)6]3- and [RhIII(NCS)(SCN)5]3-, formed in aqueous solution were successfully separated by employing methyltriphenylphosphonium (MePPh3+) and 1-ethylquinolinium (EtQu+) ions as countercations, respectively. The single-crystal X-ray analysis of (MePPh3)3[RhIII(SCN)6] (1) indicated that all of the SCN- ligands coordinate to the RhIII ion by S atoms with an octahedral symmetry, where the average bond length of Rh-S is 2.374(7) Å. On the other hand, the RhIII ion of (EtQu)3[RhIII(NCS)(SCN)5]·H2O (2) is coordinated by five S atoms and one N atom of the SCN- ligands with a C4v symmetry. Structural trans influence was observed in the shorter bond length of Rh-S at the trans position of Rh-N. The Rh-S bond length is 2.3398(13) Å significantly shorter than those of 1 by ca. 0.04 Å, although DFT calculations based on the crystal structures indicated that the effective bond order of Rh-N is higher than those of Rh-S. Thermal stability examination by thermogravimetric and differential thermal analyses (TG/DTA) and IR spectroscopy indicated that the linkage isomerization of [RhIII(SCN)6]3- to [RhIII(NCS)(SCN)5]3- proceeded after melting around 174 °C. These results clearly indicate that [RhIII(NCS)(SCN)5]3- is thermodynamically more stable than [RhIII(SCN)6]3- in solid states, although further linkage isomerization hardly occurs.

Synthesis, crystal growth and characterization of organic 1,2,4-triazole p-nitrophthalic acid (TPNP) single crystal for nonlinear optical (NLO) applications

The novel organic NLO single crystal 1,2,4-Triazole 4-nitrophthalic acid (TPNP) has been synthesised with methanol as a solvent in an equimolar ratio (1:1) by slow evaporation solution technique (SEST). The grown material was characterized for its NLO applications and reported for the first time. TPNP single crystal with the dimension of 10 mm × 5 mm × 4 mm was grown. The grown crystal was analysed through various characterization studies such as structural, optical, thermal, electrical and third harmonic generation (Z-scan) studies. The structural confirmation of the grown TPNP crystals was investigated by Single Crystal X-ray diffraction (SXRD) analysis. The Powder X-ray diffraction (PXRD) was used to identify the (h k l) planes for the purpose of drawing the morphology diagram of the original crystal image. The optical analysis carried out using UV–Vis-NIR study on TPNP crystal showed good optical transparency (80 %) and it can be used for various optical applications. To identify the structure and the functional groups, Fourier transform infrared (FTIR) study was conducted. Thermogravimetric and differential thermal analysis (TG-DTA) revealed the thermal stability of the grown TPNP crystal upto 155 °C. The surface etch pit density of TPNP crystal was carried out using chemical etching analysis. The negative photoconductive nature of title crystal was identified by photoconductivity analysis. The dielectric permittivity and dielectric loss as a function of frequency were measured for grown crystal. Intermolecular interactions and fingerprint plots of TPNP molecules are executed by Hirshfeld surface analysis. LDT of the title crystal was investigated by Q-switched Nd: YAG laser of wavelength 532 nm. Third order NLO parameters and susceptibility were determined using the Z-scan technique. It is concluded that the material can be effectively employed for various optoelectronic and photonic applications.

Enhanced photodegradation of CuCo2O4 nanoflower for the dye degradation of Rhodamine B and Methyl Violet

The investigation examined into the effect of different hydrothermal reaction temperatures and durations on the formation of nanoflower-shaped CuCo2O4 nanostructures (CCO NPs). The structural, morphological, functional, optical, and magnetic properties of the synthesized CCO NPs were thoroughly examined. The optimal calcination temperature was determined using Thermogravimetric and Differential Thermal Analysis (TG/DTA), which identified 400 °C as the ideal temperature. Following X-ray Diffraction (XRD) analysis, pure CuCo2O4 samples were formed, with calculated average crystallite sizes of 27 nm for CCO-A, 48 nm for CCO-B, 30 nm for CCO-C, and 31 nm for CCO-D samples. Fourier Transform Infrared (FTIR) analysis provided additional confirmation of pure CuCo2O4 formation, with characteristic bands in the 665–662 cm-1 and 583–567 cm-1 ranges indicating the presence of CuO and CoO bonds. SEM, High-Resolution SEM (HRSEM) and High-Resolution Transmission Electron Microscopy (HRTEM) all supported the observation of a distinct flower-like structural morphology. The optical properties of an optimized sample were revealed by UV–Visible Diffuse Reflectance Spectroscopy (UV-DRS) analysis, which revealed a band gap of 3.3 eV. According to Vibrating Sample Magnetometer (VSM) results, the magnetic behavior of CCO-D nanostructures at room temperature exhibited paramagnetic characteristics. The saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) values were determined to be 0.26218 emu/g, 2.7214 × 10–3 emu/g and 29.787 Oe, respectively. To evaluate photocatalytic performance, the CCO-D photocatalyst was used to degrade Methyl Violet and Rhodamine B dyes. CCO-D degraded MV dye with greater efficiency (93%) than RhB (85%) when exposed to sunlight. These findings highlight CCO-D's potential as a photocatalyst for the degradation of organic dyes.

Synthesis and characterisation of mesoporous MgAl2O4 hollow spheres as a high-value product in a waste recovery strategy

Micrometre-scale hollow sphere-shaped MgAl2O4 powders were synthesised using a spray-drying method, followed by calcination. An aqueous solution of mixed Mg2+ and Al3+ salts, derived from aluminium slag and serpentine tailings, served as a source of magnesium and aluminium. The secondary raw materials were subjected to acid leaching, and the refined leachates were used to prepare a spray-dried MgAl2O4 precursor, which was heat-treated at temperatures ranging from 550 °C to 1100 °C for 1 h. Characterisation of the resulting MgAl2O4 spinel powders was performed using various physicochemical techniques, including thermogravimetric and differential thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and physical adsorption using N2 (BET). The prepared MgAl2O4 spinel demonstrated several unique properties, including ultrafine particles with a uniform distribution (1–5 μm) and minimal particle agglomeration, high sintering activity (beginning at 550 °C), high purity, high specific surface area (110 m2 g-1/750 °C), and open porosity with a narrow pore size distribution (3–7 nm). These properties make the prepared MgAl2O4 spinel a highly valuable product for waste recovery strategies. The simplicity, efficiency, and cost-effectiveness of this process also predispose it to large-scale production of functional mixed metal oxides of various compositions for use in industries such as energy storage, sensing, and 3D printing fillers.

Synthesis and characterization of hydrogels from alginate and ora‐pro‐nóbis (Pereskia aculeata Miller) mucilage

AbstractThis study aimed to synthesize and characterize hydrogels prepared with alginate (ALG) and ora‐pro‐nobis mucilage (MOPN) by ionic gelation. The hydrogels were produced from solutions containing 0.5, 0.75, 1.0, and 1.25% (w/v) sodium alginate, 0.25, 0.5, 0.75, 1.0 and 1.25% (w/v) MOPN and 1.5 and 3.0% (w/v) CaCl2. The hydrogels were characterized in terms of mechanical strength, degree of swelling, morphology, chemical groups by Fourier transform infrared spectroscopy (FTIR) and x‐ray diffraction (XRD); and their thermal properties were assessed by differential scanning calorimetry (DSC) and thermogravimetric and differential thermal analysis (TG/DTA). The results indicated that MOPN acted with ALG in chain crosslinking, confirming its ability to interact with other polymers to form gels. The control hydrogel, composed of only ALG (1.5%), showed a more crosslinked and less amorphous structure with greater thermal resistance, while the hydrogel composed of ALG (1.25%) and MOPN (0.25%) showed a more amorphous, porous structure with lumps. However, these treatments were statistically equal in terms of mechanical strength and degree of swelling, indicating that ALG and MOPN hydrogels are an economically viable alternative to ALG‐only hydrogels, where 0.25% (w/v) of the ALG can be replaced by MOPN without significant changes in its mechanical and swelling properties.

CO2 adsorption by ethane periodic mesoporous organosilica at low temperatures and high pressure

In this work, the maximum CO2 adsorption capacity of an ordered mesoporous organosilica with ethylene bridges (PMO-Ethane) was studied. The maximum capture capacity was achieved for the sample at 0 °C and 34 atm (827.8 mg·g-1). This result was better than that obtained by most of the studies on other mesoporous materials found in the literature. Approximately 0.33 g of PMO-Ethane would be sufficient to shrink the concentration of atmospheric CO2 by 1 m3 to preindustrial levels. A study of successive adsorption-desorption cycles has demonstrated the material's potential for use in reversible multicycle CO2 capture processes. The CO2 adsorption curves were fitted using mathematical models: Langmuir, Freundlich, Sips, Toth, DubininRadushkevich and Temkin. Previously, several techniques were used to characterize the material: X-Ray diffraction (XRD), surface area (SBET) and porosity, thermogravimetric and differential thermal analysis (TGA-DTA), particle size, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). These results contribute to the development and use of new materials in GHG capture technologies.

Biopolymer-Capped Pyrazinamide-Loaded Colloidosomes: In Vitro Characterization and Bioavailability Studies.

This study aimed to prepare colloidosome particles loaded with pyrazinamide (PZA). These drug-loaded colloidosomes were prepared using an in situ gelation technique using a central composite design with a shell made of calcium carbonate (CaCO3) particles. Optimal amounts of 150 mg of CaCO3, sodium alginate (2%), and 400 mg of poly(3-hydroxybutyrate-co-3-hydroxy valerate) (PHBV) concentration resulted in the maximum drug loading and efficient release profile. Field emission scanning electron microscopy results showed spherical porous particles with a good coating of the PHBV polymer. Additionally, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric and differential thermal analysis (TGA-DTA), and X-ray diffraction (XRD) analysis showed good compatibility between the drug and excipients. The pharmacokinetic studies demonstrated that the drug-loaded colloidosomes resulted in 4.26 times higher plasma drug concentrations with Cmax values of 32.386 ± 2.744 mcg/mL (PZA solution) and 115.868 ± 53.581 mcg/mL (PZA-loaded colloidosomes) and AUC0-t values of 61.24 mcg-h/mL (PZA solution) and 260.9 mcg-h/mL (PZA-loaded colloidosomes), indicating that colloidosomes have the potential to be effective drug carriers for delivering PZA to the target site.