Objectives: This study investigates the magnetic and dielectric properties of nanocomposites composed of cobalt ferrite (CoFe2O4) nanoparticles embedded in a polyvinyl alcohol (PVA) matrix. Experimental: CoFe2O4 nanoparticles were synthesized via a sol-gel auto-combustion method and subsequently calcined at 600 and 900 °C. X-ray diffraction results indicated that increasing the calcination temperature from 600 to 900 °C led to an increase in crystallite size from 23.3 nm to 48.5 nm. This was accompanied by an enhancement in saturation magnetization (Ms) from 68.7 emu/g to 81.3 emu/g and a decrease in coercivity (Hc) from 1150 to 860 Oe. Conclusions: Most importantly, the PVA/CoFe2O4 composites exhibited enhanced dielectric properties compared to pure PVA. At 100 Hz, the dielectric constant (ε′) of the composite increased from approximately 18 (for PVA/CF600) to 42 (for PVA/CF900), values significantly higher than that of pure PVA, which was approximately 9. This enhancement highlights a synergistic effect between the ferrite nanoparticles and the polymer matrix, opening possibilities for designing composites with tunable dielectric responses for applications such as embedded capacitors and electromagnetic wave absorption devices

The composite of mullite/ZnₓCo₁₋xFe₂O₄ ferrite, where (x = 0.15, 0.3, 0.45), demonstrates a high efficiency in removing malachite green (MG) dye from aqueous solutions. The experimental studies revealed that the prepared composite adsorbent achieves >90

Ferrites exhibit remarkable magnetic, electrical, and surface properties, making them practical for dye removal in water treatment. The characteristics of zinc cobalt ferrite ZnxCo1−xFe2O4 nanoparticles prepared by sol-gel auto combustion technique have been studied. The effect of zinc concentration (x = 0.15, 0.3 and 0.45) on lattice parameters, magnetic properties, energy gap, and removal efficiency was investigated. The XRD and FT-IR confirmed the successful formation of a single-phase material, which exhibited a crystal structure characteristic of a face-centered cubic spinel arrangement with crystallite size ranged from 24 to 21 nm. SEM images observe the porous structure. The magnetic results of zinc cobalt ferrite showed that the saturation and remnant magnetism decreased with increasing zinc content while the coercive force reached its maximum value at x = 0.3. The adsorption method was used to study the removal of malachite green dye depending on the types of prepared ferrite. The results showed that the higher the zinc content in the cobalt ferrite, is more efficient in dye removal, and its efficiency is 59.88

Эффект замещения феррита ранее не использовавшимися элементами для управления магнитными свойствами представляет большой интерес для исследователей. Данное исследование иллюстрирует влияние низкого замещения Cs с молярными соотношениями y, равных 0,0, 0,05, 0,15 и 0,25, на структурные и магнитные свойства наночастиц CsyCo1-0.5yFe2O4. Метод синтеза являлся методом осаждения. Хлориды металлов использовались для проведения реакции в дистиллированной воде с использованием NaOH для достижения pH 10. Для всех образцов были проведены рентгеновская дифракция, полевая эмиссионная сканирующая электронная микроскопия, электронно-дисперсионная рентгенография и магнитометрия вибрирующих образцов. У всех образцов шпинельная структура в значительной степени совпадает с структурой феррита Со. Наблюдалось общее увеличение постоянной решетки с ростом содержания Cs, в то время как размер кристаллитов уменьшался примерно с 18-ти до 12,2 нм при увеличении молярного соотношения от 0 до 0,25. Электронно-микроскопическое исследование показало, что все образцы имеют сферические наночастицы без каких-либо других форм. Средний размер частиц составлял от 40 до 60 нм при увеличении содержания Cs1+. Магнитные параметры в основном показали относительно высокую коэрцитивную силу (широкие петли) и снижение насыщенности намагниченности (до 50,43 мкГ/г), кристаллической анизотропной постоянной и коэффициента квадратичности.

Porous ceramic compound as adsorbents for heavy metal removal was produced by mixing kaolin with charcoal in addition to cobalt ferrite nanoparticles at 0, 3, 5, 7, and 10 wt

Aqueous solutions with heavy metals such as Cr (VI), Pb, and Cd (II) can have an adverse effect on human health because of their toxicity. As a result, it is important to remove these heavy metals from the aquatic environment to save the human healthy. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FE-SEM) used in this research to characterize cobalt ferrite (CoFe2O4) nanoparticles and confirm the structure of Co-Fe2O4. These particles were used to make porous samples and burned at 1050 °C in mixtures of (0, 3, 5, 7, and 10) wt.% of cobalt ferrite and kaolin with 20 wt.% of charcoal. These samples serve as adsorbents that remove Pb from the wastewater. The highest rates of removal were confirmed using various treatments at (pH 3, 7, and 9). A Williamson-Hall plot was used to determine the crystal size (33) nm. The FT-IR spectra exhibited spinel-ferrite characteristics. Studies using FE-SEM demonstrated that the sample was in Nano crystalline. Using a vibrating sample magnetometer (VSM), different magnetic properties are taken from the hysteresis loops such as saturation magnetization (Ms) and remanence (Mr) and coercivity (Hc). It was found that increasing ferrite content, increased adsorption efficiency.

Nanopowders of Mn-substituted CoFe2O4 were prepared in different proportions using the sol-gel auto-combustion method and were structurally and morphologically studied. In another step, composites based on polyvinyl alcohol (PVA) with Mn-substituted CoFe2O4 fillers were prepared, and the effect of the Mn-substituted CoFe2O4 on the optical, magnetic, and dielectric properties was studied. X-ray analysis revealed the formation of polycrystalline Mn-substituted CoFe2O4. The results showed a decrease in the lattice constant with Mn2+ substituted and incorporated into the crystal structure of CoFe2O4. The Fourier confirmed the spinel structure of the Mn-substituted CoFe2O4 transform infrared spectrum where absorption bands appeared at 569-561 and 446-407 cm-1, which are attributed to tetrahedral and octahedral groups. The magnetic properties were affected when Mn ions were substituted with CoFe2O4, as shown by the results of VSM. It was observed that the saturation magnetization, remnant magnetization, and coercivity decreased with increasing Mn content. The dielectric constant and loss tangent of PVA/MnxCo1-xFe2O4 were also studied. The difference in the diameters of the substituted and host ions causes the dielectric constant to increase following the substitution of Mn ions.

This study constructed poly (vinyl alcohol)/ biphasic-calcium phosphate (PVA/ BCP) composite scaffolds. The biphasic-calcium phosphate (BCP) was incorporated in 0, 5, 10, and 25 wt%; BP0, BP1, BP2, and BP3, respectively. The surface morphology was done with a scanning electron microscope (SEM) to observe the porosity and the pore size and distribution of fabricated samples. The Fourier Transform Infrared spectroscopy (FTIR), and some physical properties such as porosity, density, swelling ratio, flexural strength, impact strength, and compression strength were also investigated. The biodegradation and bioactivity were also tested. The SEM results showed that the pores increased and became more regular and interconnected to each other with the increasing addition of BCP. The density decreased with the addition of BCP, while the porosity and mechanical properties increased with additives. The sample of BP3 has a high porosity (67%) and high impact strength (11.9 MPa). The high porosity is favorable for bone implants, and the mechanical strength must also be considered. The bio tests show that the biodegradation became regular by adding the BCP powder, which leads to ease of controlling the gradual degradation and the samples are bioactive for bone tissue. Keywords: Bone Tissue Engineering, PVA, Biphasic-Calcium Phosphate, Porosity, Mechanical properties

A stainless steel 316L (SS316L) wires reinforcing heat cure PMMA matrix samples were prepared for dentures applications. Mechanical scratching and electrochemical anodizing for PMMA denture base supported by wires of SS316L were used as straightforward and low-cost outside layer pretreatments. The two pretreatments were used to improve the flexural strength of PMMA denture bases. The mechanical scratching process acts to scratch the surface of stainless-steel wires by mixing the wires with silicon carbide powder inside a rotating Pyrex container. The pretreatment time was varied to be 60, 90, and 120min. The anodizing solution, containing ethylene glycol (EG) with HClO4 acid, was used with a 15V supply and a graphite rod as a cathode in the anodizing process. A variation in the pretreating time to be 15, 20, and 30min for the electrochemical anodizing process was included. A scanning electron microscope was utilized to examine the morphology of surfaces of the SS316L wires, which showed various morphology natures. The mechanical flexural strength test was conducted for all samples statistically to check the results. The flexural strength test results of the composite sample groups of PMMA reinforced with the scratched surface for 90 min stainless steel wire 316L presented the highest flexural strength value (113 MPa) with a 66% increment. All results proved that reinforcing PMMA by ss 316L are enhancing the flexural strength by comparing the results with previous works and pointing to the activity of the used scratching process.

Polymethyl methacrylate (PMMA) suffers from poor mechanical properties that limit its application in the bio-medical field. In this study, PMMA was reinforced with zirconium dioxide (ZrO2) and titanium dioxide (TiO2) nanopar-ticles; subsequently, the hardness, porosity, biocompatibility, bacterial adhesion, and colonization of the reinforced PMMA with various oxide nanoparticles were characterized. The results of this study indicated that reinforced material inhibits bacterial growth and decreases bacterial adhesion by decreasing porosity and increasing PMMA hardness. Based on the findings, 3 wt% PMMA-ZrO2 and 3 wt% PMMA-ZrO2 -TiO2 composites significantly inhibited bacterial growth and adherence while maintaining hemolysis PT and INR and enhancing the hardness and decreasing porosity.

Denture base poly (methyl methacrylate (PMMA) resin is one of the most frequently used materials in denture base synthesis, but due to its poor mechanical properties, PMMA can be considered a medium for the attachment and growth of a variety of pathogenic bacteria and fungi, particularly due to PMMA's pores and rough surface. The porosity percentage and surface roughness of the PMMA resin sample was lowered in this study, which resulted in a reduction in microorganisms' surface adhesion by varying the ratios of additives such as zinc oxide (ZnO) and tri-calcium phosphate (TCP) nanoparticles with (1, 2, 3, and 10% wt percent) for each additive separately, and 3% as a combination of ZnO and TCP nanoparticles in an equal ratio. Additionally, mechanical features such as surface hardness are developed, which is a critical attribute for polishing and easy finishing, as well as offering great scratch resistance during denture base cleaning. These results indicated that when compared to the other groups, PMMA (ZnO wt. 1%) and TCP-wt. 1%) reinforced composite resins demonstrated the best optimum properties. Additionally, it was discovered that adding 1% of NPs improved the mechanical qualities, which benefited the biological properties by reducing bacterial adherence to the PMMA composite resin.

This research has studied the addition effect of woven carbon fiber treated with NaOH and coated by β- TCP to the conventional polymethyl methacrylate (PMMA). Two stages are involved in the preparation of heat-cured acrylic denture composite. The first chemical treatment of woven carbon fiber (WCF) surface by different concentrations of NaOH (0.10, 0.15, and 0.20 M) and coating carbon fiber with β-TCP by various weight fractions (0.08, 0.10, and 0.12 wi) were carried out. The second stage includes the reinforcement of denture base material by treated and coated WCF. The functional groups of the WCF surface before and after alkali treatment were studied by FTIR. The morphology of the WCF surface before and after alkali treatment was observed by FESEM, the diameter of pores on the untreated and treated fibers, and the adhesion of β-TCP powder to the fiber was also observed. Mechanical tests include: impact strength (I.S.) and flexural strength (F.S) were calculated using a three-point bending test with a universal test machine and a Charpy impact test machine, respectively. From the result, reinforcing PMMA with treated and coated WCF improves the mechanical properties (impact and flexural strength).

Background: Porous scaffolds composed of poly (vinyl alcohol)/Biphasic calcium phosphate (PVA/BCP) were prepared for bone tissue engineering. The effect of BCP was investigated on the morphology of pores, porosity, compression strength, swelling ratio, biodegradation, bioactivity, and in vivo blood count. Objective: the aim of the article is to prepare a porous scaffold with good mechanical properties and suitable for the living body by having biodegradable, bioactive, and biocompatible properties. Methods: The scaffold of PVA foam was prepared using 4g of PVA (Central Drug House, M.W. 13000-23000, Viscosity 3.5-4.5, Hydrolysis 87-89 %, PH 4.5-6.5, India) dissolved in 24 ml distilled water with stirrer for 5 minutes. The biphasic-calcium phosphate (BCP) (Ying Tong Chem and Tech, LTD, Density 3.14 g/cm3, China) was added to the solution with heat stirring for 5 minutes with a ratio of 0, 0.05, 0.1 and 0.25 with respect to the weight of PVA as shows in Table 1. The sulfuric acid (Central Drug House, M.W. 98.08, India) of (8 ml) was added drop by drop using a catalyzer. The citric acid (Central Drug House, M.W. 192.13, India) was added to the mixture with 24g to create esterification bonding. Results: The results showed that the scaffold using BCP had uniform pore size distribution, suitable porosity up to 67%, and showed high swelling ratio. The scaffolds were of biodegradable nature and almost degraded by about 37.5% in four weeks. The scaffold was biologically active in terms of the presence of calcium phosphate in the hydroxyapatite phase as in bone. The in vivo biocompatibility of the PVA/BCP scaffold was tested by comparing the blood count with the normal range of blood in rabbits. After 14 days, the Blood Urea, Creatinine, A total of Bilirubin, and Lymphocytes were higher than the control. Conclusion: The addition of BCP powder has a positive effect on porosity and pore size. The compression strength value increased significantly with the use of BCP from 2.12 to 5.29 MPa. The scaffolds show good biodegradation and well bioactivity. The culture of the biomaterial caused toxicity or an acute inflammatory response, as the blood test results showed that there was infiltration of polymorphous leukocytes, lymphocytes, macrophages, and fibroblasts.

Abstract Stainless steel 316L (SS316L) as a significant bio-material, their wires were used to support the PMMA matrix. Two simple and low-cost surface pretreatments for SS316L wires were performed to enhance denture impact strength: mechanical scratching (treating SS316L wires with SiC powder inside a rotating container) and electrochemical anodizing. Three mechanical scratching samples for different periods of 60, 90 and 120min were prepared. Anodizing technique conditions were: Ethylene glycol with perchloric acid as an anodizing solution, 15V supplying and graphite rod as an anode. Anodizing process involved three pretreating periods of 15, 20, and 30min. All the prepared samples had dimensions of 65 × 10 × 3 mm. SEM technique showed different morphology nature involved holes, scratches and pores with a density of 104/μm2 and a crack length of 60μm. The PMMA reinforced with scratched stainless steel 316L wire surface for 120 min presented the highest impact strength value (42 kJ/m2) with (450.91%) increment. Anodizing samples showed a fluctuating behavior of samples with enhancing in the impact strength of anodizing wire for 20min of about 26.99 kJ/m2, which is still lower than that for scratched samples in average.

In this study unreinforced and reinforced samples with uncoated and coated woven carbon fibres (WCF) with alumina (Al2O3) and tri calcium phosphate (TCP) powders were incorporated into heat polymerised polymethyl methacrylate (PMMA) denture base resin in addition to poly vinyl alcohol (PVA) with 0.02 and 0.09 weight fraction (wi). Impact, flexural strength and water absorption of layered denture base resin have been studied. Surface morphology of the coating layers has been examined by field emission-scanning electron microscope (FE-SEM) and the toxicity of reinforcing materials were also investigated in human blood cells. Uncoated WCF sample showed high impact and flexural strength, but it still exhibits poor aesthetic. A significant increase of the impact strength values was observed in the coated specimens, in expense of flexural strength. The effect of TCP on PMMA resin was higher than when using alumina particles. Aesthetic, impact and flexural strength have improved together when PVA increased.

The purpose of this research is to increase the mechanical properties (impact and flexural strength) of acrylic polymethyl methacrylate (PMMA) denture base resin by incorporated treated and coated woven carbon fiber (WCF). To increase the roughness of fibers, WCF treated with para-aminobenzoic acid (PABA), (C7H7NO2) at 3 different concentration treatments (0.10, 0.15, and 0.20 M). In order to make the samples appears with good aesthetic and bonding, WCF was coated with β-Tricalcium phosphate (β-TCP) powder with (0.08, 0.10, and 0.12) weight fraction (wi) in addition of using polyvinyl alcohol (PVA) at 0.01 wi, respectively. After 10 days of water storage at room temperature, the specimens have been tested via using the Charpy effect measuring system and three-point bending tests. The mechanism of interfacial interaction between β-TCP and woven carbon fibers was investigated by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Based on the obtained results, when specimens contained treated and uncoated woven carbon fiber with a high concentration of (PABA), the impact and flexural strength were higher than pure sample but have a bad aesthetic. Further, (PMMA) reinforced with coated and treated woven carbon fiber as hybrid composites recorded very high raises in the mechanical properties when the concentration of (PABA) and (β-TCP) was increased, with a good aesthetic.

Excellent osteoconductivity and resorbability achieved when porous bioceramics have highsurface area that providing fast bone ingrowth. Porous samples were fabricated by using biphasic calcium phosphate BCP (achieved from HA heat treated at 850 oC) with 10 and 20 wt% of ovalbumin binder powder and mixture of carrot fibers and ovalbumin powders (1:1) then dried at 60oC and fired at 1300 oC. Structural, physical and mechanical properties of the prepared porous bioceramic were determined involved X-ray diffraction, Fourier transform infrared spectroscopy FTIR, apparent porosity, water absorption, apparent solid density and compressive strength. The results of X-ray and FTIR showed that the heat treatment of HA was succeeded in forming biphasic calcium phosphate. The apparent porosity values increased with increasing of the binder and carrot fibers content and the growths density of bacteria on bioceramics are less than natural bone. The effect of pathogenic bacteria (Pseudomonas & Staphylococcus) that cause pollution on porous calcium phosphate and natural bone (Albino mice) has been studied.

Porous poly (vinyl alcohol) scaffold samples were fabricated using nanoparticles and nano-fibers of tricalcium phosphate, which were added separately to the scaffolds with two ratios 0.05 and 0.25, respectively. Then, the results obtained were compared. The surface morphology and spectrum were examined by scanning electron microscope and Fourier transform infrared spectroscopy. The phase composition by X-ray diffraction was also examined to prove the bioactivity of the scaffold. The biodegradation, mechanical properties, porosity, density, and swelling were also tested. The impact of the strength values was enhanced significantly from 3.89 to 13.24 kJ/m(2) by using the nano-fibers of tri-calcium phosphate. However, the porosity of the tri-calcium phosphate nano-particles was higher than the tri-calcium phosphate nano-fibers by up to 62%. In fact, the porosity values in nano-fibers tri-calcium phosphate were also acceptable in comparison with the natural human bone. The samples show the highest percentage of 43% in losing weight in the G5 after incubation in phosphate buffer saline for the biodegradation test.

Nowadays, most materials used to manufacture denture base are heat-cured PMMA, to overcome the low strength of this material, different methods were used to strengthen the denture base and enhanced their properties. This study investigated the effect of glass fiber woven powder kaolinite (Al2Si2O5 (OH) 4) to influence and strength of flexure. Acrylic and kaolinite powders were mixed together and mixed again with acrylic liquid to prepare hybrid composite samples. Woven glass fiber composite was prepared by inserting woven glass fiber between the two halves of the dough. PMMA reinforced by (0, 20) wt% of woven glass fibers or/and (0, 2, 5, 7) wt% of kaolinite powder to prepare eight experimental groups (n= 7). The fractured surface was an evaluation by scanning electron microscope (SEM). X-ray diffraction and Fourier transforminfrared spectra FTIR tests were used to examine kaolinite powder. Samples were tested with the use of a Charpy testing machine for impact test and Instron tensile testing machine for flexural test after storage in water for 10 days at 37 °C. The results showed woven glass fibers with clay powder together significantly increased the mechanical properties of PMMA.