Abstract:In recent years, the use of nanotechnology (nano-particles, nanomaterial, nano-additives and nano- structured materials) has attracted attention of scholars, engineers and scientists in all scientific fields such as chemistry, medicine, material, agriculture, electronic etc. The use of nanotechnology has also become widespread in the refractory products (which mainly used in various industries such as steel, casting, cement, glass etc.). Therefore, the effect of using different types and contents of nanomaterials (oxides and non-oxides) as well as the control of microstructure has been evaluated by many researchers on the properties of shaped (bricks) and un-shaped (monolithic) refractory products. The obtained results were very promising and satisfactory. One of the most consumable refractory products in various industries is monolithic refractories, which has been widely used because of their great benefits to the other refractories products (bricks). In this paper, recent advances in monolithic refractories by using the finding of nanotechnology are presented. This article can be considered as guidance for researchers, students to gain easy access to experimental results obtained by different research group using nanotechnology and nano materials in monolithic refractories. پرونده مقاله

Diopside (DS) is a monoclinic pyroxene mineral with composition MgCaSi2O6. Lately,diopside (DS) has been introduced as a bioceramics due to its best bioactivity and biocompatibility. It has a good strength and toughness than those of hydroxyapatite (HT). In this project, bioactivity of diopside (DS) powder were evaluated and investigated. For synthesized of diopside (DS) powder, magnesium (Mg), calcite (CaCO3) and nano silicium (SiO2) powders was mechanically activate for different times. After that, the prepared powders were blended with ammonium chloride (NH4Cl) and put on various temperatures. In this part, for survey of bioactivity evaluation, the obtained dioside (DS) powders were pressed and immersed in Kukobo solution (SBF)The results indicated that nano-struacture diopside powder with crystalline size is 40 nm. The apatite formation ability,bioactivity and good mechanical behavior make it a good candidate in bone implant materials and open new insights in biomedical applications. In sum up, our findings indicated that nanostructure diopside (DS) bio-ceramic is bioactive and might make an good candidate for biomedical purposes. پرونده مقاله

Hardystonite (HT) is a monoclinic pyroxene mineral with composition Ca2ZnSi2O7. Lately, Hardystonite (HT) has been introduced as a bioceramics due to its best bioactivity and biocompatibility. It has a good strength and toughness than those of hydroxyapatite (HA). In this project, bioactivity of hardystonite (HT) powder were evaluated and investigated. For synthesized of hardystonite (HT) powder, Zinc (Zn), calcite (CaCO3) and nano silicium (SiO2) powders was mechanically activate for different times. After that, the prepared powders were blended with ammonium chloride (NH4Cl) and put on various temperatures. In this part, for survey of bioactivity evaluation, the obtained hardystonite (HT) powders were pressed and immersed in Kukobo solution (SBF)The results indicated that nano-struacture hadystonite powder with crystalline size is 40 nm. The apatite formation ability,bioactivity and good mechanical behavior make it a good candidate in bone implant materials and open new insights in biomedical engineering. The apatite formation ability,bioactivity and good mechanical behavior make it a good candidate in bone implant materials and open new insights in biomedical engineering. پرونده مقاله

Merwinite (MW) Ca3Mg(SiO4)2, has been successfully prepared by a modified sol-gel method. Optimization in calcination temperature and mechanical milling resulted in a pure and nano-sized powder which characterized by means of X-RAY diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fourier transform infrared Spectroscopy (FT–IR). We hypothesized that nano-sized merwinite (MW) would mimic more efficiently the nanocrystal structure and function of natural bone apatite, owing to the higher surface area, compare to conventional micron-size merwinite (MW).Hence, we used the unique advantage of nano- biotechnology to improve novel nano merwinite (NMW) particles as a good candidate for tissue regeneration whether as a peri - implant filling powder or in combination with other biomaterials as a composite scaffold.In contrast micron-size particles with lower surface area, lack the potency of homogeneous absorption by osteoclasts and miss the unique advantage of nanotechnology for bioactivity and resorbability. Our study suggests that nanomerwinite (NMW) might be a potential candidate by itself as a nanobioceramic filling powder or in combination with other biomaterials as a composite scaffold in bone regeneration. پرونده مقاله

In this project investigates the synthesis of single-phase nano crystalline forsterite powder by mechanical activation with subsequent annealing. To produce forsterite powder, a mixture of talc and magnesium oxide powders was first milled by a planetary ball mill, and then annealed at 1000 and 1200 8C for 1 h. The synthesized powder was characterized by X-ray diffraction (XRD), simultaneous thermal analysis (STA), scanning electron microscopy (SEM), and atomic absorption spectrometry (AAS). The initial temperature of forsterite crystallization was reduced to about 825 8C after 20 h of mechanical activation. The forsterite powder synthesized by 5 h of mechanical activation with subsequent annealing at 1000 8C for 1 h had crystallites 40 n min size. The particle size of this sample was less than 500 nm.The crystallite size of the sample obtained was 40 nm, and its particle size was submicron. The powder can equally be obtained through 20–60 h of mechanical activation with subsequent annealing at 1200 8C for 1 h, which is useful for the construction of bulk samples where higher sintering temperatures are required. AAS analysis showed that the amount of Fe and Cr in the sample ball milled for 60 h were 0.4256% and 0.00365%, respectively. پرونده مقاله

An important compete in bone tissue engineering is the development of constructs serving as scaffolds to fill bone defects, and promote bone regeneration. In this study, highly porous almost (75%) nanostructured Hardystonite/biphasic calcium phosphate scaffolds (BCPS) with interconnected porosity was developed using various hardystonite (HT) contents via space holder technique. Transmission electron microscopy (TEM), X ray diffraction (XRD) and scanning electron microscopy (SEM) techniques was employed to evaluate different samples. In addition to, the agents of scaffold composition on mechanical behavior , bioactivity and biodegradability was studied. Also, the results showed that the produced scaffolds had an average pore size and density between 250-350 µm and 2.2 ± 0.4 - 1.7 ± 0.2 gr/cm3, respectively, depending on the Hardystonite (HT) with different contents. Furthermore, increasing the hardystonite content of scaffolds from 0 (control) to 30 wt. % enhanced the bioactivity test, biodegradability, and compressive strength from 1.1 ± 0.1 to 3.1 ± 0.2 MPa, respectively. Besides, MTT assay also confirmed that the BCPS30 (containing 30 wt. % of hardystonite) significantly promoted cell viability and cell adhesion compared to BCPS 0. Totally, our project suggests that nanostructured hardystonite/BCPS with improved biological and mechanical behavior (properties) could potentially be used for biomedical engineering such as bone tissue engineering application. پرونده مقاله

In this project, the TiO2 nano-rods were synthesized from P25 TiO2 nanoparticles by hydrothermal method in 20 M NaOH solution. The effects of annealing temperatures on produced nanorods were investigated by scanning electron microscopy (SEM) X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. Diameter growth and changes of surface oxygen defects of synthesized Nano rods are studied with increasing annealing temperatures. Also, with Increase of annealing temperature over 300 °C there is no effect on the size of produced nano-rods, but due to reducing of the surface charge causes the more compact products. In summation, the effects of post heat treatment temperatures were in detail investigated by SEM, XRD and PL spectroscopy. The obtained results were shown that the increasing of annealing temperature until 300 °C causes increase of thicknesses of prepared nanorods by hydrothermal method. Increase of annealing temperature over 300 °C has no effect on the size of produced nanorods, but due to reducing of the surface charge causes the more compact products. In addition, the surface defects of synthesized 1D TiO2 were decreased because of increase of annealing temperatures, but we should note that at higher tempera tures (over 500 °C) the TiO2 phase may be converted from anatase to rutile. پرونده مقاله

In this project we prepared Hydroxyapatite (HA) with chemical formula: Ca10 (PO4)6(OH) 2 from eggshell and di-potassium-phosphate with chemical formula; K2HPO4. Adequate amount of eggshell derived Calcium Oxide (CaO) was soaked in di-potassium phosphate solution (ratio: Ca/P=1.67) at 37 Celsius degree (˚C) for different soaking times to obtain nano-crystalline HA which was characterized by X-Ray Diffraction (XRD), Transition Electron Microscopy (TEM) and FTIR studies. The crystal grain size is very little dependent on the soaking time in di-potassium-phosphate solution and the grain sizes are almost uniform and regular in shape. The egg-shell derived HA nanoparticles could be used to make scaffolds of different shapes and pore sizes for clinical uses. This process of low temperature HA synthesis is simple, and environment friendly for the mass production of pure hydroxyapatite nano- crystalline. This process of low temperature HA synthesis is simple, and environment friendly for the mass production of pure hydroxyapatite nano- crystalline. پرونده مقاله

In recent years, the use of nanotechnology (nano-particles, nanomaterial, nano-additives and nanostructuredmaterials) has attracted attention of scholars, engineers and scientists in all scientificfields such as chemistry, medicine, material, agriculture, electronic etc. The use of nanotechnologyhas also become widespread in the refractory products (which mainly used in various industries suchas steel, casting, cement, glass etc.). Therefore, the effect of using different types and contents ofnanomaterials (oxides and non-oxides) as well as the control of microstructure has been evaluatedby many researchers on the properties of shapes (bricks) and un-shaped (monolithic) refractoryproducts. The obtained results were very promising and satisfactory. One of the most consumablerefractory products in various industries is monolithic refractories, which has been widely usedbecause of their great benefits to the other refractory products (bricks). In this paper, recent advancesin monolithic refractories by using the finding of nanotechnology are presented. This article can beconsidered as guidance for researchers, students gain easy access to experimental results obtainedby different research group using nanotechnology and nano materials in monolithic refractories. پرونده مقاله

In this study, highly porous almost (75%) nanostructured Hardystonite/biphasic calcium phosphate scaffolds (BCPS) with interconnected porosity were developed using various hardystonite (HT) contents via space holder technique. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques were employed to evaluate different samples. Inaddition, the agents of scaffold composition of mechanical behavior, bioactivity, and biodegradability were studied. Also, the results showed that the produced scaffolds had an average pore size and density between 250-350 μm and 2.2 ± 0.4 - 1.7 ± 0.2 gr/cm3, respectively, depending on the Hardystonite (HT) with different contents. Furthermore, increasing the hardystonite content of scaffolds from 0 (control) to 30 wt. % enhanced the bioactivity test, biodegradability, and compressive strength from 1.1 ± 0.1 to 3.1 ± 0.2 MPa, respectively. Besides, MTT assay also confirmed that the BCPS30 (containing 30 wt. % of hardystonite) significantly promoted cell viability and cell adhesion compared to BCPS 0. Totally, our project suggests that nanostructured hardystonite/BCPS with improved biological and mechanical behavior (properties) could potentially be used for biomedical engineering such as bone tissue engineering applications. پرونده مقاله

In this study, Merwinite (MW), has been successfully prepared by a modifiedsol-gel method. Optimization in calcination temperature and mechanical millingresulted in a pure and nano-sized powder which characterized by means of(XRD), (SEM), (TEM) and (FT–IR). We hypothesized that nano-sized MW wouldmimic more efficiently the nanocrystal structure and function of natural boneapatite, owing to the higher surface area, compared to conventional micronsizeMW. Mechanical grinding in a ceramic ball mill for 6 hours resulted in (MW)nanoparticles in the range of about 33- 55 nm. Conventional micron-size MWhad been previously investigated by many researchers but it is obviously differentfrom bone mineral in aspect of mimicking the mineral resorption process. Bonecrystals of natural hydroxyapatite (NHA ) are in nano-size dimensions and possessvery large surface area. In contrast micron-size particles with lower surface arealack the potency of homogeneous absorption by osteoclasts and miss the uniqueadvantage of nanotechnology for bioactivity and resorbability. Hence, we usedthe unique advantage of nano- biotechnology to improve novel nano merwinite(NMW) particles as a good candidate for tissue regeneration whether as a peri -implant filling powder or in combination with other biomaterials as a compositescaffold. پرونده مقاله

In this project, the TiO2 nanorods were synthesized from P25 TiO2 nanoparticlesby the hydrothermal method in 20 M NaOH solution. The effects of annealingtemperatures on produced nanorods were investigated by scanning electronmicroscopy (SEM) X-ray diffraction (XRD) and photoluminescence (PL)spectroscopy. An increase of annealing temperature over 300 °C has no effect on thesize of produced nanorods, but due to reduction of the surface charge causes themore compact products. In addition, the surface defects of synthesized 1D TiO2were decreased because of an increase in annealing temperatures, but we shouldnote that at higher temperatures (over 500 °C) the TiO2 phase may be convertedfrom anatase to rutile.Diameter growth and changes of surface oxygen defects ofsynthesized Nanorods are studied with increasing annealing temperatures. Also,with an increase in annealing temperature over 300 °C, there is no effect on the sizeof produced nano-rods, but due to reduction of the surface charge causes themore compact products. پرونده مقاله

Diopside (DS) is a monoclinic pyroxene mineral with composition MgCaSi2O6. Lately,diopside (DS) has beenintroduced as a bioceramics due to its best bioactivity and biocompatibility. It has a good strength andtoughness than those of hydroxyapatite (HT). In this project, bioactivity of diopside (DS) powder wereevaluated and investigated. For synthesized of diopside (DS) powder, magnesium (Mg), calcite (CaCO3)and nano silicium (SiO2) powders was mechanically activate for different times. After that, the preparedpowders were blended with ammonium chloride (NH4Cl) and put on various temperatures. In this part, forsurvey of bioactivity evaluation, the obtained dioside (DS) powders were pressed and immersed in Kukobosolution (SBF)The results indicated that nano-struacture diopside powder with crystalline size is 40 nm.The apatite formation ability, bioactivity and better mechanical behavior make it a good candidate in boneimplant materials and open new insights in biomedicalapplications. پرونده مقاله

Nanostructured Bi2Sn2O7 and Bi2MxSn2O7 (M = Y3+, Eu3+, Gd3+ and Yb3+)nanomaterials were synthesized by conventional one-step solid state crystalgrowth reactions among Bi(NO3)3, SnCl2 and M2O3 raw materials at 800 ̊C for 10and 15 h. The doped nanomaterials were synthesized to study the capacity of thecrystal system to locate each of the dopant ions into the crystal system cavities.The synthesized nanomaterials were characterized by powder X-ray diffraction(PXRD) technique. Rietveld analysis showed that the obtained materials werecrystallized well in orthorhombic crystal structure with the space group Aba2.The PXRD data revealed that dopant ion type had a considerable influence on thecrystal phase purity of the obtained targets. The morphologies of the synthesizedmaterials were studied by field emission scanning electron microscopy (FESEM)technique. Ultraviolet-visible spectra analysis showed that the synthesizednanomaterials had strong light absorption in the ultraviolet light region.Photocatalytic performance of the synthesized nanomaterials was investigatedfor the degradation of pollutant Malachite Green under solar light condition. Theoptimum conditions were modeled and obtained by design expert software forBi2Sn2O7 that was synthesized at 800 ̊C for 10 h which were 0.06 mL H2O2, 12mg catalyst and 40 min for the removal of 50 mL of 40 ppm MG solution. Thedegradation yield in these conditions was 100 %. The photocatalytic degradationfitted to the Langmuir–Hinshelwood kinetic model. As a result of the model, thekinetic of degradation followed a pseudo-zero-order kinetic model. پرونده مقاله

This project investigates the synthesis of single-phase nano crystalline forsteritepowder by mechanical activation with subsequent annealing. To produceforsterite powder, a mixture of talc and magnesium oxide powders was first milledby a planetary ball mill, and then annealed at 1000 and 1200 8C for 1 h. Thesynthesized powder was characterized by X-ray diffraction (XRD), simultaneousthermal analysis (STA), scanning electron microscopy (SEM), and atomicabsorption spectrometry (AAS). The initial temperature of forsterite crystallizationwas reduced to about 825 8C after 20 h of mechanical activation. The forsteritepowder synthesized by 5 h of mechanical activation with subsequent annealingat 1000 8C for 1 h had crystallites 40 n min size. The particle size of this samplewas less than 500 nm. پرونده مقاله

Magnesium and its alloys are light, biodegradable, biocompatible metals that have promising applications as biomaterials. Magnesium is potentially useful for orthopedic and cardiovascular applications. However, the corrosion rate of this metal is so high that its degradation occurs before the end of the healing process. One of the ways to improve the corrosion rate is to compose it’s with ceramic materials such as HA. In this study, at first the alloy with a nominal composition of Mg-3%Al-1%Zn (AZ31 alloy) was produced by high energy ball milling (HEBM) of Mg powder, Zn powder and Al powder under high purity argon. The ball milling parameters were chosen following: shaft rotation was 600 rpm, ratio of balls to powder was 20:1 and milling time was 2, 4 and 6 h under argon atmosphere. The Mg alloy powders obtained were pressed with different amounts of HA-Zeolite nano composite powder, weight ratio HA (Hydroxyapatite) to Zeolite 4:1 ,HZ, under 1000 MPa in steel die with 10 mm in diameter and 20 mm in height. The samples pressed were sintered for 1 h at 630 K in an inert atmosphere furnace. Microstructure characterization of as-milled powders and as-sintered alloys were carried out by SEM. An X-ray diffraction (XRD) was used for phase analysis. It means that powder obtained is nano structure. Mechanical strength and El. % improved up to approximately 50% and 40% by in AZ31/HZ bio- composite samples containing 20 wt. % HZ. So, this nano biocomposite is good candidate for orthopedic medical applications. پرونده مقاله

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