Iranian Journal of Materials Science and Engineering

---

In this work, blast furnace slag (BFS) was used as an adsorbent material for the removal of Pb(II) ions in solution in batch mode. The physico-chemical analyzes used indicated that the BFS is essentially composed of silica, lime, and alumina. Its specific surface area corresponds to 275.8m²/g and its PZC is around 3.8.
The adsorption study indicated that the maximum amount of Pb(II) adsorbed under optimum conditions (agitation speed (V_ag): 150rpm; pH: 5.4; particle size (Øs): 300µm, T: 20°C) is 34.26mg/g after 50 minutes of agitation, and adsorption yield is best for feeble initial concentrations. The most appropriate isothermal model was that of Langmuir, and the adsorption speed was better characterized by the pseudo-second order kinetic model. The adsorption mechanism revealed that internal diffusion is not the only mechanism that controls the adsorption process; there is also external diffusion, which contributes enormously in the transfer of Pb(II) from solution to adsorbent. Thermodynamic study indicated that the Pb(II) adsorption on the blast furnace slag (BFS) was spontaneous, exothermic, and that the adsorbed Pb(II) is more ordered at the surface of the adsorbent. Finally, we estimate that BFS is a superb adsorbent for water containing Pb(II).
 

---

This contribution evaluates the influence of Cr doping on the ground state properties of SrTiO3 Perovskite using GGA-PBE approximation. Results of the simulated model infer agreement with the previously published literature. The modification of electronic structure and optical properties due to Cr3+ doping levels in SrTiO3 has been investigated. Structural parameters infer that Cr3+ doping alters the electronic structures of SrTiO3 by shifting the conduction band through lower energies for the Sr and Ti sites. Substituting Ti site by Cr3+ results the energy gap in being eliminated revealing a new electrical case of conducting material for the system. Furthermore, it has been noticed that Cr doping either at Sr or Ti positions could effectively develop the SrTiO3 dielectric constant properties. Consequently, Cr3+ is an effective dopant due to enhancing the optical absorption properties, thus opening up new prospects for optoelectronic applications.

---

This work aims to prepare and study amorphous carbon nitride (CNx) films. Films were deposited by reactive magnetron radiofrequency (RF) sputtering from graphite target in argon and nitrogen mixture discharge at room temperature. The ratio of the gas flow rate was varied from 0.1 to 1. Deposited films were found to be amorphous. Highest Nitrogen concentration achieved was 42 atomic percent which is very rare and therefore, the highest nitrogen to carbon atomic ratio was 0.76. The incorporation of nitrogen promotes the clustering of diamond-like sites at the expense of graphitic ones leading to the decrease of the disorder. The film surface becomes rough with increasing nitrogen concentration. Films are optically transparent in the 200-900 nm wavelength range with a wide gap varying between 3.59 and 3.63 eV. There is an increase in resistivity from 15 to 87.4 x10^-3Ω.cm for a-CN_x thin films for 0.1< R_F < 0.8 and a less decrease for   R_F > 0.8. Pore size increases in the films, but has little influence on band gaps. On the other hand, increasing the pore size reduces electrical interaction between particles by increasing resistivity.

---

Abstract
The effect of different heat-treatment temperatures on the magnetic, crystallization, and structural properties of 20SiO2.50FeO.30CaO (mol%) glass ceramics was studied. The initial glass was synthesized by the sol-gel method at 25℃  with a precursors to solvent ratio of 1/5. After aging the resulted gel for 24 h at room temperature, it was dried in an electric dryer at 110 ℃ . By heat treatment at different temperatures, different phases such as magnetite, maghemite, and hematite were crystallized in the glass. The maximum stability temperature of magnetite and maghemite were 360℃  and 440℃  respectively. By increasing the heat treatment temperature to higher than 440℃ , the oxidation of maghemite to hematite was occureds. The highest magnetization amount (1.9 emu/g) belonged to sample heat treated at 680℃ . By increasing the heat treatment temperature to 840℃ , the magnetization decreased to 0.8 emu/g, due to the oxidation of maghemite. By increasing the heat treatment temperature from 440℃  to 680℃ , crystalline size of maghemite was increased from 40 to 200 nm. By forther increment of temperature to 840℃ , the size of maghemite crystals decreased to 17nm, due to the oxidation of maghemite to hematite.
Abstract
The effect of different heat-treatment temperatures on the magnetic, crystallization, and structural properties of 20SiO2.50FeO.30CaO (mol%) glass ceramics was studied. The initial glass was synthesized by the sol-gel method at 25℃  with a precursors to solvent ratio of 1/5. After aging the resulted gel for 24 h at room temperature, it was dried in an electric dryer at 110 ℃ . By heat treatment at different temperatures, different phases such as magnetite, maghemite, and hematite were crystallized in the glass. The maximum stability temperature of magnetite and maghemite were 360℃  and 440℃  respectively. By increasing the heat treatment temperature to higher than 440℃ , the oxidation of maghemite to hematite was occureds. The highest magnetization amount (1.9 emu/g) belonged to sample heat treated at 680℃ . By increasing the heat treatment temperature to 840℃ , the magnetization decreased to 0.8 emu/g, due to the oxidation of maghemite. By increasing the heat treatment temperature from 440℃  to 680℃ , crystalline size of maghemite was increased from 40 to 200 nm. By forther increment of temperature to 840℃ , the size of maghemite crystals decreased to 17nm, due to the oxidation of maghemite to hematite.
 

---

---

Investigation the structural and magnetic properties of nanocrystalline Co₇₈Zr₁₇B₂Si₁W₂ alloy during melt spinning and annealing processes were the main goal of this study. In this regard, samples were prepared using vacuum induction melting, melt spinning and subsequent annealing. The specimens were evaluated using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), differential scanning calorimetry (DSC) and vibrating sample magnetometer (VSM). Based on results, nanocrystalline Co₅Zr single phase with hard magnetic properties (Ms=29.5 emu/g and Hc=2.7 kOe) successfully formed during melt spinning process (at wheel speed of 40 m.s^-1). The coercivity value of rapid solidified sample increased to about 3.2 kOe during annealing process up to 400°C. However, more increasing in annealing temperature lead to the transformation of non-equilibrium magnetic Co₅Zr phase to stable Zr₂Co₁₁ phase, which has distractive effects on final magnetic properties.
 

---

We report a simple and practical approach for the easy production of superhydrophobic coatings based on TiO₂-SiO₂@PDMS. In this study, we used tetraethylorthosilicate (TEOS) and titanium tetraisopropoxide (TTIP) as a precursor for the sol-gel synthesis of SiO₂ and TiO₂, respectively. Afterward, the surface of nanoparticles was modified by 1,1,1,3,3,3-hexamethyldisilazane (HMDS) before being combined with polydimethylsiloxane (PDMS). The hydrophobic property of coatings was evaluated by static contact angle measurements. The phase composition and structural evolution of the coatings were examined by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis. It was shown that changing the weight ratio of the solution composition of the coating can affect the hydrophobicity of the surface. The best sample has shown a superhydrophobic property with a 153˚ contact angle which contained (75%TiO₂-25%SiO₂) and PDMS at a weight ratio of 1:1. Moreover, the results showed that the superhydrophobic coating retains its hydrophobic properties up to a temperature of 450 ˚C, and at higher temperatures, it converts to a super hydrophilic with a water contact angle close to 0 ˚. The SiO₂-TiO₂@PDMS coating degrades methylene blue by about 55% and was shown to be capable of photocatalytically decomposing organic pollutants.

---

Graphene Nanoparticles (GNPs), an upshot of nanotechnology have attracted great interest in diverse research fields including dentistry for their unique properties. Graphene Nanoparticles are cytocompatible and when combined with other compounds, they possess improved synergistic antimicrobial and anti-adherence properties against oral pathogens. The cytotoxicity of graphene in the oral setting has been reported to be very limited in the scientific literature. Current applications of graphene include reinforcing Polymethylmethacrylate (PMMA) for the fabrication of dentures, improving properties of dental luting agents like glass ionomer cement, reinforcing restorative composites and ceramics, and improving osseointegration of titanium dental implants by coating with graphene. This paper reviews the nanoparticle ‘Graphene’ and its potential uses in the field of restorative dentistry.
 

---

Microstructure evolution and mechanical properties of Zn-22Al alloy after post-ECAP natural/artificial aging were investigated. A homogenization treatment was applied to the casting samples. In addition, after preparing the samples for the ECAP, secondary homogenization treatment was done and then the samples quenched in the water to form a fine grain structure. After 8 passes of ECAP, some ECAPed samples were naturally aged and some ECAPed samples were artificially aged. Natural aging after 8 passes of ECAP showed that Zn-22Al alloy has a quasi-stable microstructure because limited grain growth occurred. Two-phase structure of Zn-22Al alloy prevented excessive grain growth after natural aging. On the other hand, artificial aging after 8 passes of ECAP caused a relatively much grain growth took place. In shorter times of artificial aging, the grain growth rate is faster due to the high surface energy of grain boundaries. On the contrary, as the time of artificial aging increased, the surface energy of grain boundaries decreased, which leads to a decrease in the grain growth rate. In addition, texture evolution was studied after aging artificial. Therefore, the main texture of α and η phases was determined.
 

---

In the present investigation, an attempt was made to evaluate the dissolution behavior of Ti in molten KCl-LiCl. The X-ray diffraction (XRD) pattern of heated Ti plate at 800 oC for 4 h without carbon black in molten salt revealed that TiCl3 formation was feasible. For more assurance, Ti plate was heated at 950 oC for 4 h in the presence of carbon black to identify synthesized TiC. Transmission electron microscope (TEM) and scanning electron microscope (SEM) images from precursors and the final product showed that nano-crystalline TiC formation from coarse Ti particles was almost impossible without Ti dissolution. Thermodynamics calculations using Factsage software proved that it was possible to form various TiClx compounds. The TiC formation mechanism can be discussed in two possible ways: a reaction between Ti ion and carbon black for synthesizing TiC (direct) and a reaction between TiCl4 and carbon black led to indirect TiC synthesis. Elemental mapping using energy dispersive X-ray spectroscope (EDS) indicated that up to 815 oC, chlorine existed in the map. 

---

Deformation-induced α΄-martensite generally forms at shear bands in the coarse-grained austenite, while it nucleates at grain boundaries in the ultrafine-grained (UFG) austenite. The available kinetics models are related to the nucleation on the shear band intersections, and hence, their application to investigating the kinetics of α΄-martensite formation for the UFG regime cannot be justified. Accordingly, in the present work, the general Johnson–Mehl–Avrami–Kolmogorov (JMAK-type) model was implemented for comparing the kinetics of α΄-martensite formation in the UFG and coarse-grained regimes using an AISI 304L stainless steel. On the experimental front, the X-ray diffraction (XRD) patterns and the electron backscattered diffraction (EBSD) maps were used for phase and microstructural analyses, respectively. It was revealed that the simple JMAK-type model, by considering the dependency of the volume fraction of α΄-martensite on the strain, is useful for modeling the experimental data, predicting the nucleation sites based on the theoretical Avrami exponents, and characterizing the transformation kinetics at low and high strains.

---

The growth of industries, populations, and industrial activities includes environmental pollutants. Pollution causes problems such as reduced light transmission, anaerobic conditions, and complications such as allergies and cancer for humans and other living organisms. The adsorption method is one of the most attractive, and efficient methods for removing environmental pollutants such as pharmaceuticals. Among the standard methods for wastewater treatment, adsorption is more efficient than other methods and is more economical. They have a meager price. Adsorption of pollutants can be an excellent way to remove toxic substances from polluted waters and industrial effluents. In this review, pharmaceutical removal by adsorption process was reviewed in details.

---

Two-dimensional molybdenum disulfide (MoS₂) is used as a promising flame retardant and smoke suppressant nano additive in polymer composites due to its high thermal stability and layered structure. In this study, thermoplastic polyurethane (TPU) was melt-blended with MoS2 (1wt. %) and a halogen-free intumescent flame retardant (IFR) system. The IFR system consisted of ammonium polyphosphate (APP), Melamine polyphosphate (MPP), and pentaerythritol (PER), with a total amount of 25 wt. %. The TPU/IFR/MoS2 composite exhibited outstanding flame-retardant properties, achieving a UL-94 V-0 rating and a limiting oxygen index (LOI) value of 34%. Reaction-to-fire performance of the TPU/IFR/MoS2 composite was evaluated by cone calorimeter test (CCT). The CCT results indicated high flame-retardant efficiency and considerable smoke suppression performance, along with a significant decrease in the peak heat release rate (PHRR: 65.9%), peak smoke production rate (PSPR: 65.6%), and peak CO production (PCOP: 60.7%) compared to the neat TPU. The significant improvement in fire performance of TPU composite was mainly attributed to the effects of the physical barrier of MoS2 and catalytic carbonization of the IFR system. These resulted in forming an intumescent compact carbonized layer during the combustion, effectively restricting dripping. The continuous structure of the residual char was revealed by FESEM. Thermogravimetric analysis (TGA) indicated improved thermal behavior of the TPU composite in high temperatures. This work provides an effective method to improve the reaction to fire of TPU composites by incorporating traditional IFRs and MoS2, resulting in enhanced fire safety.

 
 

---

Acrylic resins are one of the most important thermoplastic resins used in various industries due to their significant properties. However, they are inherently brittle and addition plasticizers to them is very common. In this study, role of both Polyethylene Glycol (PEG) and Triacetin on the mechanical properties of acrylic resin have been investigated. To do so tensile test, bending and wear tests have been performed. To achieve the optimal mixture of plasticizers, a tensile test has been carried out, and the best percentage of the mixture has been determined. Subsequently, bending and wear tests were conducted, which showed a significant increase in the bending strength of the acrylic resin after the addition of plasticizers. Furthermore, it was found that the abrasion mechanism of the resin was significantly altered compared to its pure state.
 

---

Rice husk carbon by-product from the industrial combustion is a promising source to produce a vast amount of activated carbon adsorbent. This research prepared rice husk-activated carbon adsorbent by varying the concentration of potassium hydroxide solution (5, 10, 15, 20 % w/v) and activation time (2, 4, 6, 8 hours). Fourier-transform infrared spectral characterization (FTIR) indicated a significant effect before and after activation, especially the presence of hydroxyl groups. Based on the iodine adsorption, the specific surface area of the produced-activated carbon was approximately 615 m²/g. Experimental results showed that increasing potassium hydroxide concentration and activation time increases the water vapor adsorption capacity of the activated carbon. Compared with the rice husk carbon, the KOH-activated carbon enhanced the water vapor adsorption capacity to 931%. In the adsorption observation, changing the temperature from 15 to 27 ℃ caused a higher water vapor uptake onto the activated carbon. Two adsorption kinetics (pseudo-first- and pseudo-second-order models) were used to evaluate the adsorption mechanism. This research found that rice husk-activated carbon performed a higher water vapor adsorption capacity than other adsorbents (silica gel, zeolite, and commercially activated carbon).

---

Biogenic synthesis of papain-conjugated copper metallic Nanoparticles and their antibacterial and antifungal activities Papain metallic conjugated nanoparticles (Papain-CuNPs) were synthesised using Papain and CuSO4.5H₂O. Papain-CuNPs were characterized using UV-visible spectroscopy, FT-IR, HR-TEM, XRD, FE-SEM, zeta potential, and a zeta sizer. The antibacterial activity of papain-CuNPs against human infectious microorganisms (Citrobacter spp, Pseudomonas aeruginosa and Candida albicans) was investigated. The mechanism of action of papain-CuNPs was evaluated using FE-SEM and HRTM. UV spectroscopy confirmed the plasma resonance (SPR) at 679 nm, which indicated the formation of papain-CuNPs. The FT-IR spectrum absorbance peaks at 3927, 3865, 3842, 3363, 2978, and 2900 cm^-1 indicate the presence of O-H and N-H of the secondary amine, and peaks at 1643 and 1572 cm^-1 represent C=O functional groups in Papain-CuNPs. EDAX analysis confirmed the presence of copper in the papain-CuNPs. The zeta potential (-42.6 mV) and zeta size (99.66 d. nm) confirmed the stability and size of the nanoparticles. XRD confirmed the crystalline nature of the papain-CuNPs. FE-SEM and HRTM showed an oval structure, and the nano particles' 16.71244–34.84793 nm. The synthesized papain-NPs showed significant antibacterial activity against clinical P. aeruginosa (15 mm). MIC 125 µg/ml) showed bactericidal activity against P. aeruginosa and the mechanism of action of Papain-NPs was confirmed using an electron microscope by observing cell damage and cell shrinking. Papain-CuNPs have significant antibacterial activity and are thus used in the treatment of P. aeruginosa infections

---

The trimanganese tetraoxide (Mn₃O₄) nanostructured thin films doped with 2 mol % of nickel (Ni) and molybdenum (Mo) ions were deposited by a simple electrophoretic deposition technique. The structural, optical, and morphological studies of these doped thin films were compared with pure Mn₃O₄ thin films. X-ray diffraction (XRD) confirmed the tetragonal Hausmannite spinel structure. The Fourier transform infrared spectroscopy (FTIR) provided information about the molecular composition of the thin films and the presence of specific chemical bonds. The optical study and band gap energy values of all thin films were evaluated by the UV visible spectroscopy technique. The scanning electron microscopy (SEM) illustrated the morphological modifications of the Mn₃O₄ thin films due to doping of the nickel and molybdenum ions. The Brunauer Emmett Teller (BET) method has confirmed the mesoporous nanostructure and nanopores of the thin films. The supercapacitive performance of the thin films was studied by cyclic voltammetry (CV), and galvanostatic charge discharge (GCD) techniques using the three-electrode arrangement. An aqueous 1M Na₂SO₄ electrolyte was used for the electrochemical study. The 2 mol % Ni doped Mn₃O₄ thin film has shown maximum specific capacitance than pure and Mo doped Mn₃O₄ thin films. Hence, this study proved the validity of the strategy - metal ion doping of Mn₃O₄ thin films to develop it as a potential candidate for electrode material in the futuristic energy storage and transportation devices.

---

In this research work, Cadmium Sulphide thin film deposited on to glass substrate in a non-aqueous medium at 80 °C. The various physical preparative parameters and the deposition conditions, such as the deposition time and temperature, concentrations of the chemical species, pH, speed of mechanical stirring, etc., were optimized to yield good quality films. The as-prepared sample is tightly adherent to the substrate's support, less smooth, diffusely reflecting and was analyzed for composition. The synthesized film is characterized using X- ray diffraction (XRD), electrical and optical properties. It appears that the composites are rich in Cd. The grown CdS thin film had an orange-red color. A band gap of CdS thin film is 2.41 eV.  The average crystallite size of the CdS film was 21.50 nm. The resistivity of the CdS thin film is about 5.212 x 10⁵ W cm.
 

---

Iron oxide nanoparticles has attracted extensively due to their supermagnetic properties, preferred in biomedicine because of their biocompatibility and potential nontoxicity to human beings. Synthesis of iron nanoparticles (FeNPs) was prepared with the help of ferric chloride and ferrous sulphate by using the coprecipitation method. The variation and combination of ferric and ferrous concentrations affect the physical and magnetic properties of iron oxide nanoparticles.  The effect of 0.1 M ferric and ferrous concentration on iron oxide nanoparticles studied separately and in combination. The obtained nanoparticles were characterized by Particle size, zeta potential, Ultraviolet (UV-visible), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Thermal gravimetric analysis (TGA), and Vibrating-sample magnetometer (VSM) techniques. Particle size was below 200nm and zeta potential was within the limit for all the batches. UV visible spectra at 224 nm, and FTIR exhibit two peaks at 510 and 594 cm-1, indicating iron oxide NPs and XRD confirmed the crystalline nature of Fe. SEM showed a spherical shape for all batches. The use of a combination of ferric and ferrous is more effective than its individual use. TGA and VSM studies confirmed its magnetic properties.