AMAR Djemli
عمر جملي
amar.djemli@univ-msila.dz
0778435168
- Departement of Chemistry
- Faculty of Sciences
- Grade MCB
About Me
Location
Msila, Msila
Msila, ALGERIA
Code RFIDE- 1990-08-14 00:00:00
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AMAR Djemli birthday
- 2026-02-13
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2026-02-13
Synthesis, optical and electrical properties of (Ce0.2Nd0.2Sm0.2Ho0.2Yb0. 2)2Zr2O7 high-entropy for optoelectronic applications
In this work, a novel high-entropy zirconate, (Ce0.2Nd0.2Sm0.2Ho0.2Yb0.2)2Zr2O7 (RE-HESZ), was successfully synthesized via a conventional solid-state reaction route and comprehensively characterized. X-ray diffraction coupled with Rietveld refnement revealed a temperature-driven structural evolution, where a disordered defect-fluorite phase (Fm −3m) formed at 1673 K transforms into a well-ordered single-phase pyrochlore structure (Fd−3m) upon sintering at 1773–1873 K. Thermalexpansion measurements demonstrated excellent thermal stability, with a low average coefcient of thermal expansion of 9.6 ×10⁻6 K⁻1 over the 373–1473 K range, attributed to the rigid [ZrO6] octahedral framework. Optical investigations using UV–Vis diffuse reflectance spectroscopy indicated an indirect optical bandgap of 2.35 eV, confrming the semiconducting nature of the material. Impedance spectroscopy performed between 473 and 673 K revealed non-Debye relaxation behavior and a negative temperature coefcient of resistance, with grain boundaries dominating the dielectric response and accurately described by an equivalent R–C–CPE circuit model. AC conductivity obeys Jonscher’s universal power law, yielding a high-temperature activation energy of approximately 1.09 eV. The frequency exponent analysis indicates that charge transport is mainly governed by the correlated barrier hopping mechanism, with a maximum barrier height of 0.29 eV. Dielectric measurements further revealed a high dielectric permittivity (~ 104) accompanied by strong interfacial polarization effects. These combined structural, thermal, optical, and electrical characteristics demonstrate that RE-HESZ is a robust multifunctional material with strong potential for high-temperature capacitors, thermistors, and optoelectronic applications.
Citation
Foudil SAHNOUNE , AMAR Djemli , Iheb Garoui, Djaida Redaoui, Khawla Djilat, Nourah A. Alsobai, Abderrazek Oueslati, , (2026-02-13), Synthesis, optical and electrical properties of (Ce0.2Nd0.2Sm0.2Ho0.2Yb0. 2)2Zr2O7 high-entropy for optoelectronic applications, Applied Physics A, Vol:132, Issue:, pages:1-26, Springer Nature
- 2025-11-01
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2025-11-01
Study on structural, thermal stability, optical, and electrical properties of (Nd₀.₂₅Sm₀.₂₅ho₀.₂₅Yb₀.₂₅)₂Zr₂O₇ medium-entropy ceramic for optoelectronic applications
Defect-fluorite-type and pyrochlore-type rare-earth A₂B₂O₇ ceramics are widely studied for their attractive structural and functional properties. Medium-entropy rare-earth zirconate (Nd₀.₂₅Sm₀.₂₅Ho₀.₂₅Yb₀.₂₅)₂Zr₂O₇ is synthesized through solid-state reaction and characterized for its structural, thermal, optical, and electrical properties. X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirm a single-phase, disordered fluorite structure and a dense microstructure with approximately 0.5 μm grains. The material exhibits a coefficient of thermal expansion (CTE) of 9.62 × 10−6 °C−1 over the temperature range of 100 to 1300 °C, highlighting its potential for high-temperature applications, such as thermal barrier coatings (TBCs) in gas turbines and aerospace systems. UV–Vis analysis reveals a direct band gap of 1.68 eV, suggesting a potential optoelectronic utility. Impedance spectroscopy shows non-Debye relaxation, with AC conductivity following Jonscher's law and activation energies of 1.013 eV at high temperature ranges. This study demonstrates that (Nd₀.₂₅Sm₀.₂₅Ho₀.₂₅Yb₀.₂₅)₂Zr₂O₇ ceramics hold significant potential as a promising candidate for high-temperature applications.
Citation
Foudil SAHNOUNE , AMAR Djemli , 4. Khawla Djilat, Ibtihel Soudani, Djaida Redaoui, Abderrazek Oueslati, , (2025-11-01), Study on structural, thermal stability, optical, and electrical properties of (Nd₀.₂₅Sm₀.₂₅ho₀.₂₅Yb₀.₂₅)₂Zr₂O₇ medium-entropy ceramic for optoelectronic applications, Inorganic Chemistry Communications, Vol:181, Issue:1, pages:115091, ELSEVIER
- 2025-10-10
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2025-10-10
Mg-Modified ZSM-5 Zeolite: A High-Performance Green Inhibitor for Aluminum Corrosion Protection in Acidic Solutions
This study aimed to investigate the corrosion inhibition behavior of zeolitic materials on aluminum in 1 M HCl solution. This investigation used electrochemical methods (polarization curves and electrochemical impedance spectroscopy). Polarization curves indicate that the inhibition mechanism primarily acts as a mixed-type inhibitor, with the corrosion rate of aluminum in 1 M HCl reduced by 99.57% at an inhibitor concentration of 100 ppm. Electrochemical impedance diagrams demonstrate that inhibition occurs through a charge transfer process on a heterogeneous surface across all tested zeolite concentrations. Scanning electron microscopy micrographs revealed that the formed film effectively blocked acid attack through physical and chemical adsorption on the aluminum surface.
Citation
AMAR Djemli , S. Hambli, K. Abderrahim, M. Benbouzid, A. Sid, Talal M. Althagafi, S. Abderrahmane, K. Moussaoui, D. Belfennache, R. Yekhlef, M. Fatmi, , (2025-10-10), Mg-Modified ZSM-5 Zeolite: A High-Performance Green Inhibitor for Aluminum Corrosion Protection in Acidic Solutions, Protection of Metals and Physical Chemistry of Surfaces, Vol:61, Issue:1, pages:681–689, Pleiades Publishing
- 2025-09-24
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2025-09-24
Characterization of Cu-5Fe (wt.%) fabricated by powder consolidation using high-pressure torsion
Bulk pure Cu and Cu-5Fe (wt%) materials were successfully fabricated at room temperature by powder consolidation using high-pressure torsion (HPT) processing through 30 turns under a pressure of 6 GPa. The microstructure, texture and mechanical properties of the fabricated bulk discs were systematically characterized across their diameters using electron backscatter diffraction, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Vickers microhardness. Additionally, their thermal stability was evaluated after annealing treatment at 500 °C for 6 h. The results show that two grain refinement stages occurred in the Cu disc accompanied by the formation of partial A-fibre ( / and A components). The dynamic recrystallization was delayed in the Cu-5Fe disc owing to the pinning effect of Fe content. Consequently, the grain refinement was more effective, and the texture gradually developed the B, A and components. The Cu-5Fe disc was harder than the Cu disc, and the microhardness increased across the disc diameter. Rapid grain growth with a high amount of Cu2O oxide and retained texture were the main characteristics of the annealed Cu disc. The precipitation of Fe phase during annealing led to the development of a duplex microstructure at the centre and mid-radius positions and a stable microstructure at the edge of the Cu-5Fe disc. Eventually, the annealing texture was transformed into a complete A-fibre ( / and A/ components) which was quite similar to the Cu disc. The microhardness decreased after annealing but it was more homogeneously distributed across the disc diameter than the HPT-processed disc. The results were discussed based on the different grain refinement mechanisms, static recrystallization mechanisms, solute elements, dislocations and annealing twins.
Citation
AMAR Djemli , Hiba AZZEDDINE , Foudil SAHNOUNE , Piotr Bazarnik, Yi Huang, Thierry Baudin, François Brisset, Megumi Kawasaki & Terence G. Langdon, , (2025-09-24), Characterization of Cu-5Fe (wt.%) fabricated by powder consolidation using high-pressure torsion, Journal of Materials Science, Vol:60, Issue:40, pages:19267–19293, Springer Nature
- 2025-08-11
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2025-08-11
Mechanical and Thermal Characterization of Polyoxymethylene: Strain Rate Sensitivity, Crystallinity and Failure Mechanisms
Polyoxymethylene (POM) is a high-performance semi-crystalline thermoplastic widely used for its excellent mechanical strength, wear resistance, and dimensional stability. This study investigates the mechanical and thermal behavior of POM under large deformations through tensile testing and thermal analysis. The results indicate that POM exhibits linear elastic behavior at low strains, transitioning to nonlinear viscoelastic and plastic behavior at higher deformations. Stress whitening and microvoid formation significantly influence failure mechanisms. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) confirm POM’s high crystallinity (~40%) and thermal stability, with a melting temperature of 166°C. Scanning Electron Microscopy (SEM) reveals cavitation and fibrillation as dominant damage mechanisms. The findings highlight the challenges of substituting POM due to its unique property balance. Further research should focus on predictive plasticity models to optimize POM’s industrial applications
Citation
AMAR Djemli , Sid Ahmed Reffas,, M. Elmmaguenni, R. Yekhlef, D. Belfennache, Talal M. Althagafi, M. Fatmi, , (2025-08-11), Mechanical and Thermal Characterization of Polyoxymethylene: Strain Rate Sensitivity, Crystallinity and Failure Mechanisms, Physics of the Solid State, Vol:67, Issue:8, pages:642–654, Springer Nature
- 2025-07-17
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2025-07-17
Effect of halogen substitution on the electronic and optical behavior of C₁₆H₁₀X₂O₂(X = F, cl, Br and I) organic semiconductors
In this study, a comprehensive analysis of the structural, electronic, and optical properties of C₁₆H₁₀X₂O₂ compounds (where X = F, Cl, Br, I) was conducted using first-principles calculations based on Density Functional Theory (DFT). The results demonstrate that the substitution of different halogens significantly influences the electronic structure and optical properties of these organic compounds. Structural data revealed a systematic relationship between crystal lattice constants and the atomic radius and electronegativity of the substituted halogen atoms, with an observed increase in the c/a and c/b ratios when moving from F to I. Electronic band structure analysis showed that the band gap follows the pattern Br < Cl < F < I, indicating that brominated derivatives exhibit more pronounced semiconducting behavior. Partial Density of States (PDOS) curves confirm the pivotal role of halogen p orbitals in determining the properties of upper valence bands. Regarding optical properties, reflectivity, absorption, refractive index, and loss function spectra were analyzed across an energy range of 0–40 eV, revealing systematic variations correlated with the type of halogen substituent. Chlorine-containing compounds exhibited the highest reflectivity, absorption, and loss function values in the 15–25 eV range, while iodine-containing compounds showed the highest refractive index in the low-energy region. These structure-property relationships provide valuable insights for designing organic materials with specific electronic and optical properties for advanced organic electronics applications.
Citation
AMAR Djemli , MohamedAmine GHEBOULI , M. Fatmi, B. Ghebouli, S. Alomairy, Faisal Katib Alanaz, , (2025-07-17), Effect of halogen substitution on the electronic and optical behavior of C₁₆H₁₀X₂O₂(X = F, cl, Br and I) organic semiconductors, Scientific Reports, Vol:15, Issue:1, pages:25891, Nature
- 2025-07-01
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2025-07-01
Study on morphological, FTIR, optical band-gap and AC conductivity of Li2CoP2O7 for advanced applications
Lithium diphosphates, and particularly Li2CoP2O7, have garnered increasing attention due to their promising properties for applications in energy storage and electronic devices. In the present study, Li2CoP2O7 was successfully synthesized using a conventional solid-state reaction route. X-ray powder diffraction (XRD) analysis confirmed the formation of a pure monoclinic phase with C2/c space group symmetry and an average grain size of approximately 2.66 μm. Infrared (IR) spectroscopy revealed distinct vibrational modes characteristic of P2O74− groups, in line with the expected structural framework. Optical absorption measurements indicated that the material exhibits semiconducting behavior, with an estimated indirect band gap of approximately 3.78 eV. Dielectric studies demonstrated that Li2CoP2O7 possesses excellent dielectric performance, including a remarkably high dielectric constant (∼2 × 108), suggesting its suitability for low-frequency energy storage applications. Impedance spectroscopy measurements revealed a non-Debye relaxation mechanism, with temperature-dependent relaxation dynamics analyzed using the Arrhenius model. Furthermore, the frequency-dependent ac conductivity followed Jonscher's universal power law, and the behavior of the frequency exponent s was consistent with the correlated barrier hopping (CBH) conduction model. Overall, these findings offer valuable insights into the dielectric relaxation processes and charge transport mechanisms in Li2CoP2O7, underscoring its potential for high-performance applications in advanced electronic systems and energy storage technologies.
Citation
Foudil SAHNOUNE , AMAR Djemli , Samia Aydi, Obaidallah A. Algethami, Sami Znaidia, Abderrazek Oueslati, , (2025-07-01), Study on morphological, FTIR, optical band-gap and AC conductivity of Li2CoP2O7 for advanced applications, RSC Advances, Vol:15, Issue:33, pages:27154-27166, Royal Society of Chemistry
- 2025-05-12
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2025-05-12
Structural, Elastic, Mechanic, Electronic, and Thermodynamic of LiMoN2 Compound for Electronic and Energy Storage
This study explores the structural, elastic, mechanical, electronic, and thermodynamic properties of the LiMoN2 compound using ab initio calculations based on density functional theory (DFT). The compound’s hexagonal structure exhibits intriguing characteristics, including metallic conductivity and strong Mo–N bonding. Elastic constants confirm its stability under pressures up to 40 GPa, with an analysis of anisotropy and mechanical properties indicating a ductile nature. The electronic structure, dominated by Mo-d and N-p states, suggests potential applications in electronic systems, with features such as a high density of states at the Fermi level pointing to superconductivity. Thermodynamic properties, including heat capacities, Debye temperature, and entropy, are evaluated under varying temperatures and pressures, demonstrating its thermal stability and suitability for high-performance applications. These results provide a comprehensive understanding of the LiMoN2 compound’s properties and its potential for advanced material applications.
Citation
AMAR Djemli , , (2025-05-12), Structural, Elastic, Mechanic, Electronic, and Thermodynamic of LiMoN2 Compound for Electronic and Energy Storage, Physics of the Solid State Article, Vol:67, Issue:2025, pages:356–366, Springer Nature
- 2025-02-18
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2025-02-18
Design of an Advanced Sensor Based on Surface Plasmon Resonance with Ultra-High Sensitivity
This study presents the development of a high-sensitivity surface plasmon resonance (SPR) sensor featuring an innovative structure composed of a BK7 prism glass, copper (Cu) thin film, titanium dioxide (TiO₂), nickel (Ni), and a two-dimensional black phosphorus (BP) layer combined with a sensing medium. The sensor utilizes an angular interrogation technique, with its performance parameters sensitivity (S), detection accuracy (DA), and quality factor (QF) analyzed using the attenuated total reflection (ATR) and transfer matrix method (TMM). The results demonstrate significant improvements in the full-width at half-maximum (FWHM), detection accuracy, quality factor, and sensitivity due to the hybrid TiO₂, Ni, and BP layers. The impact of copper thickness is also thoroughly investigated. The study identifies optimal sensor performance with a sensitivity of 518°/RIU and a quality factor of 91.51/RIU, achieved with optimized thicknesses of 35 nm (Cu), 2 × 4 nm (TiO₂), 10 nm (Ni), and 0.53 nm (BP). Furthermore, an alternative configuration yields even higher sensitivity, achieving 526°/RIU and a quality factor of 96.51/RIU, with a copper thickness of 35 nm, TiO₂ thickness of 2 × 2 nm, and nickel thickness of 15 nm. The enhanced sensitivity and performance of the TiO₂, Ni, and BP hybrid layers suggest their promising applicability in diverse biosensing scenarios. This study highlights the potential of this optimized SPR sensor configuration for advanced biosensing applications, owing to its high sensitivity and improved quality factor.
Citation
AMAR Djemli , , (2025-02-18), Design of an Advanced Sensor Based on Surface Plasmon Resonance with Ultra-High Sensitivity, Plasmonics, Vol:25, Issue:3, pages:2820, Springer Nature
- 2024-12-18
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2024-12-18
Effect of Atriplex halimus Leaf as Ecofriendly Surfactant for Demulsification of Water in Crude Oil Emulsion
Water-crude oil emulsion causes challenges, which the petrochemical sector solves using efficient, ecologically friendly, and cost-effective demulsifying chemicals. With this work, we aim to solve the problem of the presence of water in Algerian oil after it has left the producing well by adding a natural material, widely used in the country, as an environmentally friendly demulsifier. Atriplex halimus L. leaf ATP powder (ATP-P) and leaf extract (E-ATP) were studied. We first characterized the two biosurfactants ATP-P and E-ATP by attenuated total reflectance (ATR), X-ray diffraction (XRD), and thermogravimetry analysis (TGA). The effect of ATP-P and E-ATP on the emulsion (water/oil) was studied by Fourier transform infrared spectroscopy (FTIR) analysis, microscopic, rheological behavior, interfacial tension (IFT), and bottle tests. The results obtained show the ability of the two biosurfactants E-ATP and ATP-P to separate water, with water separation reaching 99% in 30 minutes with 500 ppm of E-ATP, while ATP-P separates 98% in 92 minutes. The mechanism of action of the two compounds as biodemulsifiers can be traced back to the rheological study, which showed a 33% reduction in emulsion viscosity at 500 ppm; ATR-FTIR analysis also shows the disappearance of carbon-carbon and carbon-oxygen bonds, responsible for the reduction in oil viscosity. A decrease in surface tension by 41.48% by adding P-ATP and 57.95% by adding E-ATP contributed to the integration of water molecules and increased separation speed. Microscopic analysis shows an increase in the volume diameter of the water droplets, more than threefold when E-ATP is added and more than twofold when ATP-P is added.
Citation
AMAR Djemli , , (2024-12-18), Effect of Atriplex halimus Leaf as Ecofriendly Surfactant for Demulsification of Water in Crude Oil Emulsion, SPE Journal, Vol:18, Issue:, pages:1-17, SOC PETROLEUM ENG
- 2024-11-15
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2024-11-15
Kinetics of formation, microstructure, and properties of monolithic forsterite (Mg2SiO4) produced through solid-state reaction of nano-powders of MgO and SiO2
The synthesis of forsterite can be challenging because the initial oxides react slowly and undesirable compounds like enstatite (MgSiO3) can form instead of forsterite (Mg2SiO4). Although several methods have been developed to overcome these challenges, the synthesis of forsterite using the solid-state reaction of nanopowders has not been investigated. This study aims to explore the possibility of producing forsterite by reacting MgO and SiO2 nano-powder. The initial oxides were wet ball milled, dried, and reaction sintered. Spectroscopy and microscopy methods were used to analyze the formed phases and study the formation kinetics. The density, coefficient of thermal expansion (CTE), and hardness of sintered samples were measured using a densimeter, a dilatometer, and a hardness tester, respectively. The results demonstrated that it is possible to synthesize forsterite by solid state reaction of pure MgO and SiO2 nano-powders. The reaction between the two compounds begins at a temperature as low as 860 °C and leads to the formation of forsterite by a two-step formation mechanism. The first reaction involves the reaction of MgO and SiO2 to form enstatite, and the second one produces forsterite as a result of enstatite reacting further with MgO. The activation energy values ranged from 1028.89 to 1105.655 kJ/mol for the formation of forsterite, and from 456.316 to 488.08 kJ/mol for the formation of enstatite. Monolithic forsterite was completely formed at a low temperature of 1200 °C for a relatively short duration of 2 h. The sample sintered at 1400 °C for 2 h, had a density of 2.96 g/cm3, a Vickers hardness of 7.64 GPa, and a coefficient of thermal expansion of 10.24 × 10−6/K measured in the temperature range of 200–1300 °C.
Citation
KHADIDJA Laziri , AMAR Djemli , Foudil SAHNOUNE , Djaida Redaoui, Essebti Dhahri, Syed Fida Hassan, Nouari Saheb, , (2024-11-15), Kinetics of formation, microstructure, and properties of monolithic forsterite (Mg2SiO4) produced through solid-state reaction of nano-powders of MgO and SiO2, Ceramics International, Vol:50, Issue:22, pages:10, Elsevier
- 2024-11-01
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2024-11-01
Ultra-sensitivity of surface plasmon resonance sensor using halide perovskite FASnI3 and 2D materials on Cu thin films
This paper studies a novel surface plasmon resonance (SPR) biosensor using a BK7 glass prism, a copper (Cu) metal plasmonic layer, which combine a halide perovskite (FASnI3) with two-dimensional (2D) materials such as phosphorus black, graphene and TMDC (MoS2, MoSe2, WS2, WSe2) for the detection of breast cancer cells. We have optimized the thickness of each layer in order to obtain maximum sensitivity. A numerical study mainly uses the transfer matrix principle, while the attenuation total reflection method involves examining the reflection properties. The evaluation of SPR biosensor configurations serves to obtain optimal performance. The simulation results indicate that the integration of halide perovskite (FASnI3) and 2D materials into the BK7/Cu/medium sensing structure significantly improves the sensitivity and figure of merit (ZT). The outstanding results in terms of sensor performance characteristics are observed in the BK7/Cu (48 nm)/FASnI3 (5 nm)/BP (0.53 nm) configuration. The figure of merit and sensitivity estimated at 123.11 RIU−1 and 459.28°/RIU, with a notable improvement of 338.45 %.
Citation
AMAR Djemli , , (2024-11-01), Ultra-sensitivity of surface plasmon resonance sensor using halide perovskite FASnI3 and 2D materials on Cu thin films, Results in Physics, Vol:66, Issue:66, pages:108004, Elsevier
- 2024-08-01
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2024-08-01
Detection of tuberculosis using palladium -tantalum diselenide (Pd-TaSe2) bases SPR biosensor
This study presents a novel structure to improve the SPR biosensor’s sensitivity that is employed for tuberculosis detection. The structure consists of five layers: CsF prism glass, silver thin film, Pd and the material 2D TaSe2 layer with sensing medium, it uses an angular interrogation technique. Attenuated total reflection (ATR) and the transfer matrix method (TMM) are used to investigate the highly performance parameters of the biosensors in terms of sensitivity (S), detection accuracy (DA) and figure of merit (FOM). The result of the research is that the sensitivity of the Pd and TaSe2 hybrid layer is improved, and the full half maximum also increased but decreased in (DA) and (FOM) values. The hybrid Pd and TaSe2 layer improved sensitivity, the full-at-half maximum has also increased but decreased (DA) and (FOM) values. Analysis of silver thickness effect is also investigated. The highest sensitivity is obtained at 410°/RIU with optimized thicknesses of Ag, Pd, and TaSe2 of 40 nm, 15 nm, and 1 nm, respectively. The proposed SPR biosensor looks promising for use in various biosensing applications.
Citation
AMAR Djemli , , (2024-08-01), Detection of tuberculosis using palladium -tantalum diselenide (Pd-TaSe2) bases SPR biosensor, Journal of Optics, Vol:2, Issue:7, pages:1-8, Springer India
- 2024-03-30
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2024-03-30
Sustainable porcelain ceramics production using local raw materials and recycled automotive glass
The main objective of this research is the explanation of the replacement of feldspar limestone imported from Spain with recycled automotive glass, in order to reduce waste and promote environmental sustainability. Details and efforts of making porcelain ceramics from local raw materials such as quartz, kaolin and glass are also given. Replacing the feldspar with reclaimed automotive glass shows the effect of the Na2O and CaO solvents contained in the glass on the sintering and crystallization of the studied porcelain. The results showed that the added glass contributes to the reduction of the density and the acceleration of the sintering process, by occupying the sites of the open spaces, observed in the samples not containing feldspars. By reaching a nonporous ratio at a temperature of 1000∘C, the melting of the material is accelerated due to the dissolved oxides it contains, in addition to the linear shrinkage rate in samples that contain a lot of glass reaching the normal level of porcelain (about 12%) at low temperature compared to ordinary porcelain.
Citation
AMAR Djemli , , (2024-03-30), Sustainable porcelain ceramics production using local raw materials and recycled automotive glass, Modern Physics Letters B, Vol:38, Issue:12, pages:2450064, World Scientific Publishing Company