This document summarizes a study on the synthesis of barium hexaferrite (BaFe12O19) nanoparticles through co-precipitation and calcination. The researchers investigated the effect of the Fe3+/Ba2+ molar ratio and addition of surface active agents on the structural and magnetic properties of the synthesized nanoparticles. They found that decreasing the Fe3+/Ba2+ ratio from the stoichiometric value of 12 to 8 and increasing the calcination temperature to 1000°C or higher promoted the formation of single phase BaFe12O19 nanoparticles. The addition of surface active agents also helped form homogeneous BaFe12O19 nanoparticles as small as 113 nm at the lower calcination temperature of 800°C, with
Microstructure and Fracture Toughness of Gadolinium Aluminates Sinthesized vi...IRJESJOURNAL
Abstract: Gadolinium aluminate (GAO) was prepared by reverse chemical precipitation out of reagent grade chemical salt precursors i.e. gadolinium oxide and aluminum sulphate derived pseudoboehmite. The obtained gel like precipitates were dried, and calcined at various temperatures. Powders were uniaxially pressed into compacts and sintered in air up to 1600°C. Calcined and sintered compacts were characterized by XRD, FESEM, HRTEM, Raman spectroscopy, Arquimedes density measurements, Vickers indentation micro hardness, and fracture toughness (KIC) from crack indented specimens. Compacts were sintered up to 98.3±3.3 % high density values. Gadolinium aluminate perovskite GdAlO3 phase (GAP) was mainly found throughout all the processing and sintering cycle, however a monoclinic low strength gadolinium aluminate, Gd4Al2O9 (GAM) impurity phase was steadily found to be present despite tight stequiometric and processing control. Such impurity phase was found to lower the fracture toughness down to 0.12±0.01 MPa.m1/2 .
Synthesis, Structure Investigation and Dyeing Assessment of Novel Bisazo Disp...IOSR Journals
Novel bisazo-disperse dyes were prepared by the coupling of diazotized solutions of various aromatic diamines with 2,4-dihydroxybenzophenone. The resultant bisazo disperse dyes were characterized by elemental analysis, IR and 1H NMR spectral studies. The UV Visible absorption spectral data were investigated in dimethylformamide. and are discussed in terms of structural property relationship. Their dyeing assessment of bisazo disperse dyes has been made on polyester fabrics. The results show that a better hue was obtained on polyester fabrics and have mild to moderate fastness properties.
Vardenafil is a PDE5 inhibitor used to treat erectile dysfunction. This document discusses several studies that developed and validated analytical methods for quantifying vardenafil concentration. One study used thin layer chromatography with densitometric detection to simultaneously estimate vardenafil and dapoxetine in pharmaceutical formulations. Another used HPLC with amperometric detection employing a boron-doped diamond electrode to determine vardenafil and related metabolites in plasma. A third developed a HPLC-chemiluminescence method to quantify trace levels of vardenafil in dietary supplements.
This document summarizes a study that investigated the influence of temperature and pH on the morphology and color of cobalt aluminate (CoAl2O4) spinel powders prepared by the sol gel method. X-ray diffraction and infrared spectroscopy confirmed the formation of the spinel phase starting at 500°C regardless of pH. Transmission electron microscopy showed the powders were nanometric in size ranging from 20-90 nm, with particle size increasing with temperature. Colorimetry found the powders became increasingly blue at higher temperatures above 800°C, regardless of pH. The results indicate temperature strongly influences morphology and color, while pH has a significant but lesser effect. Powders synthesized at 1100°C and pH 7 had the best
The document summarizes research on producing hydroxyapatite (HAp) prototypes from gypsum/polyvinyl alcohol (PVA) composites. Porous gypsum blocks were produced by adding PVA to gypsum powder and molding. The blocks were then converted to HAp through chemical reaction in ammonium phosphate and hydroxide solutions. Characterization techniques confirmed the structures of gypsum, PVA composite, and final HAp. HAp prototypes after 36 hours of reaction showed predominant HAp peaks via XRD and EDS identified calcium and phosphorus. The HAp had high porosity (80%) and low compression strength (3.5 MPa) suitable for bone growth.
Chemical Formula of Alxoy on Synthesize Of Al2o3 For Buffer Catalyst by Sol-G...theijes
Heterogeneous catalyst used in the process of improving the oxidative stability of biodiesel is the Pt-Rh-Pd catalyst supported by γ-Al2O3 (γ-alumina). The purpose of this research was to know the effect of sintering and calcination treatment in sol-gel process on the atomic weight ratio of Al/O that could affect the formation of γ-alumina phase as buffer catalyst. Precursors used was Al (NO3)3.9H2O, NH4OH and (C6H8O7) to be dissolved in Aquabidestilate. The calcination process was performed at a temperature which varied of 190oC, 275oC and 320oC for 4 hours respectively and sinter process carried out at a temperature of 420oC for 4,6 and 8 hours. XRD test results confirm that all of the powder has a single phase with different ratio of Al/O atomic weight. For calcination process at a temperature of 320oC for 4 hours and sintering at 420oC for 4, 6, and 8 hours was obtained powder with the atomic weight ratio of Al/O in accordance with ratio of Al/O in Al2O3 compound is 0.6667 (2/3). Alumina with the smallest particle size of 84.5 nm is owned by powder with ratio of Al/O = 0.6667. Morphology of the crystals is not homogen in size and shape and it is still agglomerated.
FTIR Spectrum of BiFeO3 Ceramic Produced By Sol-Gel Method Based On Variation...theijes
High purity BiFeO3 (BFO) powder was synthesized by sol-gel method using bismuth nitrate, iron nitrate as sources and citric acid as fuel. The calcination treatment of the citric acid gel was at 160oC and 200oC for 4 hours respectively. Sintering treatment was varied at 600oC for 4, 6 and 8 hours respectively. The powder has been characterized by Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA) to know reference temperatures of calcination and sintering, X Ray Diffraction (XRD) test to confirm BFO phase and Fourier Trasform Infra Red (FTIR) to identify chemical bonds in a molecule by producing an infrared absorption spectrum. TGA/DTA results show that loss of mass and heat flow is at 160oC approximately, it is used as reference of calcination temperature. XRD results show that the BFO powder sintered at 600oC for 8 hours exhibits no secondary phase, Bi2O3. Meanwhile, FTIR Spectrum shows that powder had single phase BFO is having wave number 1385 cm-1 (C-H), 1560 cm-1 (C-C) and 2930 cm-1 (C-H).
Barium titanate (BaTiO3) doped with rare-earth elements (REE) is used as dielectric in the manufacture of multilayer ceramic capacitors (MLCCs). The most common REE oxide employed as dopant for this application is Y2O3. The behavior of the Y3+ in the BaTiO3 structure depends on its concentration and the sintering conditions, among other factors, which can induce the formation of secondary phases that are a potential cause a detriment to the electrical properties of BaTiO3. The purpose of this work is to perform a phase characterization of BaTiO3 doped with different concentrations of Y2O3, validating its possible contribution to the formation of secondary phases. The role of Y2O3 was evaluated on two kinds of raw materials. The first one is pure BaTiO3 (< 100 ppm Y) and the second kind is a commercial formulation designed for MLCCs known as X7R (-55°C and 125°C, 15% tolerance), which among other elements, already contained 1 wt% of Y2O3. High concentrations of Y2O3 (1% up to 20 wt%) were used aiming to promote structural changes, and even the formation of secondary phases in amounts suitable to be detected by X-ray diffraction. Heat treatment of powder and sintering of ceramics (powder compacted at 2 MPa) were conducted in air (1310°C in air for 3 h, two steps: 1350°C then 1150°C 15 h). A phase transition from tetragonal to a mixture of tetragonal and cubic was observed as Y2O3 concentration increases in the thermally treated powder and in the corresponding ceramics. Commercially formulated powder showed higher densification than pure BaTiO3, and produced cubic structure at higher Y2O3concentrations. The phase Ba6Ti17O40is detected in the 20 wt% Y2O3-doped sample.
Microstructure and Fracture Toughness of Gadolinium Aluminates Sinthesized vi...IRJESJOURNAL
Abstract: Gadolinium aluminate (GAO) was prepared by reverse chemical precipitation out of reagent grade chemical salt precursors i.e. gadolinium oxide and aluminum sulphate derived pseudoboehmite. The obtained gel like precipitates were dried, and calcined at various temperatures. Powders were uniaxially pressed into compacts and sintered in air up to 1600°C. Calcined and sintered compacts were characterized by XRD, FESEM, HRTEM, Raman spectroscopy, Arquimedes density measurements, Vickers indentation micro hardness, and fracture toughness (KIC) from crack indented specimens. Compacts were sintered up to 98.3±3.3 % high density values. Gadolinium aluminate perovskite GdAlO3 phase (GAP) was mainly found throughout all the processing and sintering cycle, however a monoclinic low strength gadolinium aluminate, Gd4Al2O9 (GAM) impurity phase was steadily found to be present despite tight stequiometric and processing control. Such impurity phase was found to lower the fracture toughness down to 0.12±0.01 MPa.m1/2 .
Synthesis, Structure Investigation and Dyeing Assessment of Novel Bisazo Disp...IOSR Journals
Novel bisazo-disperse dyes were prepared by the coupling of diazotized solutions of various aromatic diamines with 2,4-dihydroxybenzophenone. The resultant bisazo disperse dyes were characterized by elemental analysis, IR and 1H NMR spectral studies. The UV Visible absorption spectral data were investigated in dimethylformamide. and are discussed in terms of structural property relationship. Their dyeing assessment of bisazo disperse dyes has been made on polyester fabrics. The results show that a better hue was obtained on polyester fabrics and have mild to moderate fastness properties.
Vardenafil is a PDE5 inhibitor used to treat erectile dysfunction. This document discusses several studies that developed and validated analytical methods for quantifying vardenafil concentration. One study used thin layer chromatography with densitometric detection to simultaneously estimate vardenafil and dapoxetine in pharmaceutical formulations. Another used HPLC with amperometric detection employing a boron-doped diamond electrode to determine vardenafil and related metabolites in plasma. A third developed a HPLC-chemiluminescence method to quantify trace levels of vardenafil in dietary supplements.
This document summarizes a study that investigated the influence of temperature and pH on the morphology and color of cobalt aluminate (CoAl2O4) spinel powders prepared by the sol gel method. X-ray diffraction and infrared spectroscopy confirmed the formation of the spinel phase starting at 500°C regardless of pH. Transmission electron microscopy showed the powders were nanometric in size ranging from 20-90 nm, with particle size increasing with temperature. Colorimetry found the powders became increasingly blue at higher temperatures above 800°C, regardless of pH. The results indicate temperature strongly influences morphology and color, while pH has a significant but lesser effect. Powders synthesized at 1100°C and pH 7 had the best
The document summarizes research on producing hydroxyapatite (HAp) prototypes from gypsum/polyvinyl alcohol (PVA) composites. Porous gypsum blocks were produced by adding PVA to gypsum powder and molding. The blocks were then converted to HAp through chemical reaction in ammonium phosphate and hydroxide solutions. Characterization techniques confirmed the structures of gypsum, PVA composite, and final HAp. HAp prototypes after 36 hours of reaction showed predominant HAp peaks via XRD and EDS identified calcium and phosphorus. The HAp had high porosity (80%) and low compression strength (3.5 MPa) suitable for bone growth.
Chemical Formula of Alxoy on Synthesize Of Al2o3 For Buffer Catalyst by Sol-G...theijes
Heterogeneous catalyst used in the process of improving the oxidative stability of biodiesel is the Pt-Rh-Pd catalyst supported by γ-Al2O3 (γ-alumina). The purpose of this research was to know the effect of sintering and calcination treatment in sol-gel process on the atomic weight ratio of Al/O that could affect the formation of γ-alumina phase as buffer catalyst. Precursors used was Al (NO3)3.9H2O, NH4OH and (C6H8O7) to be dissolved in Aquabidestilate. The calcination process was performed at a temperature which varied of 190oC, 275oC and 320oC for 4 hours respectively and sinter process carried out at a temperature of 420oC for 4,6 and 8 hours. XRD test results confirm that all of the powder has a single phase with different ratio of Al/O atomic weight. For calcination process at a temperature of 320oC for 4 hours and sintering at 420oC for 4, 6, and 8 hours was obtained powder with the atomic weight ratio of Al/O in accordance with ratio of Al/O in Al2O3 compound is 0.6667 (2/3). Alumina with the smallest particle size of 84.5 nm is owned by powder with ratio of Al/O = 0.6667. Morphology of the crystals is not homogen in size and shape and it is still agglomerated.
FTIR Spectrum of BiFeO3 Ceramic Produced By Sol-Gel Method Based On Variation...theijes
High purity BiFeO3 (BFO) powder was synthesized by sol-gel method using bismuth nitrate, iron nitrate as sources and citric acid as fuel. The calcination treatment of the citric acid gel was at 160oC and 200oC for 4 hours respectively. Sintering treatment was varied at 600oC for 4, 6 and 8 hours respectively. The powder has been characterized by Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA) to know reference temperatures of calcination and sintering, X Ray Diffraction (XRD) test to confirm BFO phase and Fourier Trasform Infra Red (FTIR) to identify chemical bonds in a molecule by producing an infrared absorption spectrum. TGA/DTA results show that loss of mass and heat flow is at 160oC approximately, it is used as reference of calcination temperature. XRD results show that the BFO powder sintered at 600oC for 8 hours exhibits no secondary phase, Bi2O3. Meanwhile, FTIR Spectrum shows that powder had single phase BFO is having wave number 1385 cm-1 (C-H), 1560 cm-1 (C-C) and 2930 cm-1 (C-H).
Barium titanate (BaTiO3) doped with rare-earth elements (REE) is used as dielectric in the manufacture of multilayer ceramic capacitors (MLCCs). The most common REE oxide employed as dopant for this application is Y2O3. The behavior of the Y3+ in the BaTiO3 structure depends on its concentration and the sintering conditions, among other factors, which can induce the formation of secondary phases that are a potential cause a detriment to the electrical properties of BaTiO3. The purpose of this work is to perform a phase characterization of BaTiO3 doped with different concentrations of Y2O3, validating its possible contribution to the formation of secondary phases. The role of Y2O3 was evaluated on two kinds of raw materials. The first one is pure BaTiO3 (< 100 ppm Y) and the second kind is a commercial formulation designed for MLCCs known as X7R (-55°C and 125°C, 15% tolerance), which among other elements, already contained 1 wt% of Y2O3. High concentrations of Y2O3 (1% up to 20 wt%) were used aiming to promote structural changes, and even the formation of secondary phases in amounts suitable to be detected by X-ray diffraction. Heat treatment of powder and sintering of ceramics (powder compacted at 2 MPa) were conducted in air (1310°C in air for 3 h, two steps: 1350°C then 1150°C 15 h). A phase transition from tetragonal to a mixture of tetragonal and cubic was observed as Y2O3 concentration increases in the thermally treated powder and in the corresponding ceramics. Commercially formulated powder showed higher densification than pure BaTiO3, and produced cubic structure at higher Y2O3concentrations. The phase Ba6Ti17O40is detected in the 20 wt% Y2O3-doped sample.
The document summarizes a study on the oriented interfacial microstructures that form in single fiber polymer composites containing graphene fibers. Graphene oxide fibers were produced via wet spinning and then chemically reduced to graphene fibers. These graphene fibers were embedded in isotactic polypropylene (iPP) matrix and subjected to isothermal melt crystallization. Polarized optical microscopy and scanning electron microscopy showed that the iPP crystallizes perpendicularly to the fiber axis, forming a transcrystalline interphase around the graphene fiber. Various factors that influence the transcrystallization process were investigated.
Simple methods for forming protein monolayers lab on-a-chip 2013AnteoDx
1. Mix&Go is a novel surface chemistry that uses metal polymers to activate surfaces for protein binding. It forms thin films below 5 nm that allow proteins to bind as mono-layers while maintaining stability and function.
2. Experiments showed that Mix&Go could activate a variety of surfaces for protein binding, including glass, polystyrene, and gold. It formed stable mono-layers of proteins like streptavidin and antibodies.
3. Mix&Go performed better than conventional methods in assays, requiring less capture protein to achieve similar signals. This suggests it forms cleaner mono-layers versus stacked multi-layers with other methods. Mix&Go could enable new biosensor designs requiring stringent protein-surface interfaces.
Analysis of the Change in Curing Temperatures as a Result of Hydrolysis of El...inventionjournals
The document analyzes how hydrolysis changes the curing temperatures of electrostatic thermosetting powder coating residue. Differential scanning calorimetry and Kofler hot bench experiments were used to analyze residues before and after hydrolysis. The results showed that hydrolysis increased the temperatures at which the residues started to form film coatings on metal surfaces by 60°C for one residue and 30°C for another. Hydrolyzed residues also reacted differently in DSC analyses, demonstrating endothermic regions in both heating cycles due to their altered structure from hydrolysis. Thus, hydrolysis makes the residues workable at higher temperatures suitable for recycling processes like extrusion and injection molding.
1. Precipitation is an easy and cost-effective process to produce nano-sized particles using inexpensive source materials like inorganic chemicals.
2. Precipitation often results in hard aggregation of primary particles during washing, filtration, and drying which must be addressed.
3. Methods to prevent aggregation include controlling crystal growth, maintaining a constant pH washing solution to encourage electrostatic repulsion, and ball milling dried aggregates with less polar solvents.
Solid state reactions involve reacting solids to form new solids and compounds. They have advantages like simple apparatus and low cost but also disadvantages like wide particle size distributions, need for high temperatures, and risk of contamination. Key factors that influence solid state reactions include particle size and distribution, mixing homogeneity, compaction between particles, and reaction temperature. Finer particle sizes and narrower distributions can promote more complete reactions at lower temperatures by increasing contact points between reactants.
Modification & Application of Borate Zirconia CatalystRanjeet Kumar
Solid catalysts are of great advantages in alkylation reaction due to heterogenous reaction which makes separation of catalysts very easy and environment friendly. Here, sulfated and borate zirconia catalysts are used to search for ortho-xylene with Toluene & methanol. To find a new path to get o-xylene, catalysts surface was studied and a new mesoporous borate zirconia catalyst was prepared. Mesoporous Borate Zirconia had showed a very efficient path to manufature o-xylene.
Study the Effect of the Untreated and Treated Fly Ash on the Mechanical Prope...YogeshIJTSRD
Ordinary fly ash type C is modified the surface by the agents KOH 3M, Silane Silquest in acidic condition pH = 4 and Stearic acid 2 , respectively. Mixture of bisphenol A epoxy resin GELR 128 resin A and Bisphenol F epoxy resin EPOTEC 170LV F resin is prepared by agitating well in a glass with a agitating speed of 200 rpm at a temperature of 50°C and a time of 30 minutes. Modified fly ash was dispersed into mixture of epoxy resin and then solidified with Kingcure K11 hardener. The results showed that the mechanical properties of the polymer composites based on mixture of bisphenol A and bisphenol F with treated fly ash 10 , 20 , 30 by weight cured by Kingcure K11 hardener were higher than that of untreated fly ash composites. Bach Trong Phuc | Pham Duc Trinh | Nguyen Thanh Liem "Study the Effect of the Untreated and Treated Fly Ash on the Mechanical Properties of the Polymer Composites Based on a Mixture of Bisphenol a and Bisphenol F Epoxy Resin Cured by Kingcure K11 Hardener" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd39950.pdf Paper URL: https://www.ijtsrd.com/chemistry/polymer-chemistry/39950/study-the-effect-of-the-untreated-and-treated-fly-ash-on-the-mechanical-properties-of-the-polymer-composites-based-on-a-mixture-of-bisphenol-a-and-bisphenol-f-epoxy-resin-cured-by-kingcure-k11-hardener/bach-trong-phuc
The document discusses sulfated zirconia as a solid acid catalyst. It describes the synthesis of sulfated zirconia through precipitation and impregnation methods. Characterization using XRD, FTIR, TG-DTA, and textural properties is also discussed. The acidity and super acidic properties of sulfated zirconia are examined. Applications testing sulfated zirconia for organic transformations like the Prins cyclization reaction and selective hydrolysis of cellulose into glucose are summarized. Optimization of the Prins reaction and recycling of the sulfated zirconia catalyst are highlighted.
The document summarizes research on the phase transformation of sol-gel titania containing silica. Key findings include:
1) The addition of 5-10% silica to titania increases the specific surface area of the material from 89 m2/g to over 200 m2/g. Using ethanol as the solvent medium achieved the highest surface area of 232 m2/g.
2) The addition of silica increases the anatase-rutile phase transformation temperature of titania from around 800°C to higher temperatures.
3) The phase transformation was studied using X-ray diffraction and impedance spectroscopy. The addition of methanol or ethanol was found to enhance the formation of the rutile
This document discusses chromatography techniques including gas chromatography (GC) and high performance liquid chromatography (HPLC). It provides details on:
- The basic principles and components of GC and HPLC, including stationary and mobile phases used.
- Operating conditions for an example HPLC system including detector type, data processor, solvents, column, flow rate, wavelength.
- Types of GC columns including packed and capillary.
- Applications of chromatography techniques for analyzing pesticides like herbicides, organochlorine pesticides, organophosphorus pesticides, and pyrethroids.
- An example method for analyzing organochlorine pesticides using GC with specifics on equipment, temperature, carrier
This document summarizes research on the preparation and characterization of titanium-doped barium ferrite (BFTO) nanopowders. BFTO powders with compositions of BaFe(12-x)TixO19, where x=0.32 and x=0.36, were synthesized using a sol-gel method. The powders were characterized using XRD, SEM, and FTIR. XRD analysis confirmed the formation of a single tetragonal phase and particle sizes ranging from 15-50 nm. SEM images showed irregularly shaped plate-like particles 10-40 nm in size. FTIR spectra exhibited peaks corresponding to metal-oxygen bonds and residual organic groups from the synthesis method.
This document provides background information on analytical methods for determining bisphenol A (BPA) levels in food and biological samples. It discusses sample preparation techniques like solvent extraction and solid-phase extraction. It also covers separation and detection methods like liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Finally, it notes that validated analytical methods are available for reliably measuring free and total BPA levels in foods and some biological samples, though validation is limited for conjugated BPA levels in biological samples. Care must still be taken to avoid cross-contamination during sampling and analysis.
IJERD(www.ijerd.com)International Journal of Engineering Research and Develop...IJERD Editor
1. The document summarizes research on synthesizing an infrared transparent glass based on descriptions in an ancient Indian text called AMSHUBODHINI. Raw materials were mixed in ratios specified in the text and melted to produce a non-hygroscopic greenish-yellow calcium glass.
2. Characterization of the glass found it to be transparent in the infrared wavelength range of 5000 to 1200 cm-1, comparable to calcium fluoride glass. Unlike other infrared transparent materials which are hygroscopic, this glass was found to be non-hygroscopic.
3. The research successfully produced an infrared transparent glass from ancient text specifications. The glass has potential infrared applications and advantages over other materials due to its
This document discusses research into using different methods to create co-crystals of active pharmaceutical ingredients (APIs). It focuses on attempts to form co-crystals of caffeine and theophylline through various crystallization routes, including milling, solution growth, and grinding with solvents. Differential scanning calorimetry and X-ray diffraction analysis found that while a sharp melting peak appeared around 202°C for samples, no new co-crystal phase was produced and the samples consisted of just physical mixtures of the original components. A binary phase diagram also supported the lack of co-crystallization.
This document provides an outline for a paper on hydroxyapatite (HAp), including an introduction to HAp and why it is important, the chemistry of HAp, techniques for producing and processing HAp powder, and areas for future research. Specifically, it discusses that HAp is widely used in bioceramics due to its bioactivity and stability, outlines several techniques for producing HAp powder including hydrothermal, sol-gel, and microwave irradiation methods, and indicates that future research opportunities include developing new biomaterials that more closely mimic the structure and properties of natural bone and teeth.
The paper presents an overview of nucleating agents and their effects on crystallization rate, mechanical properties, and thermal properties in polypropylene. Presented at the SPE Automotive TPO Engineered Polyolefins Global Conference, October 2002, while working at Ciba Specialty Chemicals.
This document evaluates the pozzolanic reactivity of calcined kaolinite clay. Various characterization techniques were used to analyze structural changes during calcination, including XRD, thermal analysis, and NMR. The results showed the kaolinite transformed from crystalline to amorphous phases with increasing calcination temperature. Pozzolanic reactivity, as measured by the Chapelle test, was highest for samples calcined at 600-750°C, indicating these have potential as cement additives.
This document discusses the development and optimization of mix designs for low calcium fly ash and slag based geopolymer concrete of grades G30 and G50, equivalent to conventional concrete grades of M30 and M50. The mix designs were developed based on parameters such as alkaline liquid to fly ash ratio, sodium silicate to sodium hydroxide ratio, sodium hydroxide molarity, curing method, temperature, and curing time. Specimens were cast and tested according to code procedures at 3, 7, and 28 days to evaluate compressive strength. An optimum mix design was selected for each grade based on a comparative study of the compressive strength results for the different parameters.
Graphene oxide grafted with iridium complex as a superior heterogeneous catal...Pawan Kumar
A novel graphene oxide (GO)-immobilized heteroleptic iridium complex was synthesized and demonstrated
as a first heterogenized homogeneous catalyst for the production of dimethylformamide (DMF)
from carbon dioxide, hydrogen, and dimethylamine. The synthesized hybrid catalyst showed comparable
activity as homogeneous heteroleptic iridium complex with additional benefits such as facile recovery
and recycling of the catalyst. After completion of the reaction, the heterogeneous catalyst was easily
recovered by filtration, and reused for subsequent recycling processes without any significant change in
the catalytic efficiency
Graphene oxide grafted with iridium complex as a superior heterogeneous catal...Pawan Kumar
A novel graphene oxide (GO)-immobilized heteroleptic iridium complex was synthesized and demonstrated
as a first heterogenized homogeneous catalyst for the production of dimethylformamide (DMF)
from carbon dioxide, hydrogen, and dimethylamine. The synthesized hybrid catalyst showed comparable
activity as homogeneous heteroleptic iridium complex with additional benefits such as facile recovery
and recycling of the catalyst. After completion of the reaction, the heterogeneous catalyst was easily
recovered by filtration, and reused for subsequent recycling processes without any significant change in
the catalytic efficiency.
Graphene oxide grafted with iridium complex as a superior heterogeneous catal...Pawan Kumar
A novel graphene oxide (GO)-immobilized heteroleptic iridium complex was synthesized and demonstrated
as a first heterogenized homogeneous catalyst for the production of dimethylformamide (DMF)
from carbon dioxide, hydrogen, and dimethylamine. The synthesized hybrid catalyst showed comparable
activity as homogeneous heteroleptic iridium complex with additional benefits such as facile recovery
and recycling of the catalyst. After completion of the reaction, the heterogeneous catalyst was easily
recovered by filtration, and reused for subsequent recycling processes without any significant change in
the catalytic efficiency.
ACETYLATION OF BENZYLIC ALCOHOLS OVER BiFeO3 (BFO), Bi0.86Sm0.07Eu0.07FeO3 (B...EDITOR IJCRCPS
BiFeO3 (BFO), Bi0.86Sm0.07Eu0.07FeO3 (BSEFO), and Bi0.86Sm0.07Cd0.07FeO3 (BSCFO) nanopowders were prepared by the sol-gel
combustion method and the catalytic performances were evaluated in acetylation reaction of benzyl alcohol. The physical chemical
properties of catalysts were characterized by using XRD, FT-IR, scanning electron microscope (SEM), EDX and BET surface.
Efficient acetylation of benzyl alcohol was carried out over all the nano powders using acetyl chloride/ acetonitrile at room
temperature. Among the nanopowders, BSCFO showed the highest catalytic performance and the yield of benzyl acetate was 89,
45, and 69 percent over BSCFO, BFO, and BSEFO, respectively. Partial substitution of Sm-Eu and Sm-Cd in bismuth ferrite
improved the catalytic performance and increased the specific surface area of the catalysts. A direct relationship was resulted
between catalytic performance and surface of catalysts, where BSCFO with the highest surface area (111m2/g) exhibited the
superior catalytic performance. The quantitative yield for acetate product was also resulted for acetylation of p-methyl benzyl
alcohol, p-nitro benzyl alcohol and p-chloro benzyl alcohol on BSCFO. The catalysts showed good reusability in the process. The
study confirmed the catalysts could be promising catalyst for acetylation of alcohols.
Keywords: Europium, Samarium, Bismuth ferrites, nano perovskite, doping, Acetylation, benzylic alcohols.
The document summarizes a study on the oriented interfacial microstructures that form in single fiber polymer composites containing graphene fibers. Graphene oxide fibers were produced via wet spinning and then chemically reduced to graphene fibers. These graphene fibers were embedded in isotactic polypropylene (iPP) matrix and subjected to isothermal melt crystallization. Polarized optical microscopy and scanning electron microscopy showed that the iPP crystallizes perpendicularly to the fiber axis, forming a transcrystalline interphase around the graphene fiber. Various factors that influence the transcrystallization process were investigated.
Simple methods for forming protein monolayers lab on-a-chip 2013AnteoDx
1. Mix&Go is a novel surface chemistry that uses metal polymers to activate surfaces for protein binding. It forms thin films below 5 nm that allow proteins to bind as mono-layers while maintaining stability and function.
2. Experiments showed that Mix&Go could activate a variety of surfaces for protein binding, including glass, polystyrene, and gold. It formed stable mono-layers of proteins like streptavidin and antibodies.
3. Mix&Go performed better than conventional methods in assays, requiring less capture protein to achieve similar signals. This suggests it forms cleaner mono-layers versus stacked multi-layers with other methods. Mix&Go could enable new biosensor designs requiring stringent protein-surface interfaces.
Analysis of the Change in Curing Temperatures as a Result of Hydrolysis of El...inventionjournals
The document analyzes how hydrolysis changes the curing temperatures of electrostatic thermosetting powder coating residue. Differential scanning calorimetry and Kofler hot bench experiments were used to analyze residues before and after hydrolysis. The results showed that hydrolysis increased the temperatures at which the residues started to form film coatings on metal surfaces by 60°C for one residue and 30°C for another. Hydrolyzed residues also reacted differently in DSC analyses, demonstrating endothermic regions in both heating cycles due to their altered structure from hydrolysis. Thus, hydrolysis makes the residues workable at higher temperatures suitable for recycling processes like extrusion and injection molding.
1. Precipitation is an easy and cost-effective process to produce nano-sized particles using inexpensive source materials like inorganic chemicals.
2. Precipitation often results in hard aggregation of primary particles during washing, filtration, and drying which must be addressed.
3. Methods to prevent aggregation include controlling crystal growth, maintaining a constant pH washing solution to encourage electrostatic repulsion, and ball milling dried aggregates with less polar solvents.
Solid state reactions involve reacting solids to form new solids and compounds. They have advantages like simple apparatus and low cost but also disadvantages like wide particle size distributions, need for high temperatures, and risk of contamination. Key factors that influence solid state reactions include particle size and distribution, mixing homogeneity, compaction between particles, and reaction temperature. Finer particle sizes and narrower distributions can promote more complete reactions at lower temperatures by increasing contact points between reactants.
Modification & Application of Borate Zirconia CatalystRanjeet Kumar
Solid catalysts are of great advantages in alkylation reaction due to heterogenous reaction which makes separation of catalysts very easy and environment friendly. Here, sulfated and borate zirconia catalysts are used to search for ortho-xylene with Toluene & methanol. To find a new path to get o-xylene, catalysts surface was studied and a new mesoporous borate zirconia catalyst was prepared. Mesoporous Borate Zirconia had showed a very efficient path to manufature o-xylene.
Study the Effect of the Untreated and Treated Fly Ash on the Mechanical Prope...YogeshIJTSRD
Ordinary fly ash type C is modified the surface by the agents KOH 3M, Silane Silquest in acidic condition pH = 4 and Stearic acid 2 , respectively. Mixture of bisphenol A epoxy resin GELR 128 resin A and Bisphenol F epoxy resin EPOTEC 170LV F resin is prepared by agitating well in a glass with a agitating speed of 200 rpm at a temperature of 50°C and a time of 30 minutes. Modified fly ash was dispersed into mixture of epoxy resin and then solidified with Kingcure K11 hardener. The results showed that the mechanical properties of the polymer composites based on mixture of bisphenol A and bisphenol F with treated fly ash 10 , 20 , 30 by weight cured by Kingcure K11 hardener were higher than that of untreated fly ash composites. Bach Trong Phuc | Pham Duc Trinh | Nguyen Thanh Liem "Study the Effect of the Untreated and Treated Fly Ash on the Mechanical Properties of the Polymer Composites Based on a Mixture of Bisphenol a and Bisphenol F Epoxy Resin Cured by Kingcure K11 Hardener" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd39950.pdf Paper URL: https://www.ijtsrd.com/chemistry/polymer-chemistry/39950/study-the-effect-of-the-untreated-and-treated-fly-ash-on-the-mechanical-properties-of-the-polymer-composites-based-on-a-mixture-of-bisphenol-a-and-bisphenol-f-epoxy-resin-cured-by-kingcure-k11-hardener/bach-trong-phuc
The document discusses sulfated zirconia as a solid acid catalyst. It describes the synthesis of sulfated zirconia through precipitation and impregnation methods. Characterization using XRD, FTIR, TG-DTA, and textural properties is also discussed. The acidity and super acidic properties of sulfated zirconia are examined. Applications testing sulfated zirconia for organic transformations like the Prins cyclization reaction and selective hydrolysis of cellulose into glucose are summarized. Optimization of the Prins reaction and recycling of the sulfated zirconia catalyst are highlighted.
The document summarizes research on the phase transformation of sol-gel titania containing silica. Key findings include:
1) The addition of 5-10% silica to titania increases the specific surface area of the material from 89 m2/g to over 200 m2/g. Using ethanol as the solvent medium achieved the highest surface area of 232 m2/g.
2) The addition of silica increases the anatase-rutile phase transformation temperature of titania from around 800°C to higher temperatures.
3) The phase transformation was studied using X-ray diffraction and impedance spectroscopy. The addition of methanol or ethanol was found to enhance the formation of the rutile
This document discusses chromatography techniques including gas chromatography (GC) and high performance liquid chromatography (HPLC). It provides details on:
- The basic principles and components of GC and HPLC, including stationary and mobile phases used.
- Operating conditions for an example HPLC system including detector type, data processor, solvents, column, flow rate, wavelength.
- Types of GC columns including packed and capillary.
- Applications of chromatography techniques for analyzing pesticides like herbicides, organochlorine pesticides, organophosphorus pesticides, and pyrethroids.
- An example method for analyzing organochlorine pesticides using GC with specifics on equipment, temperature, carrier
This document summarizes research on the preparation and characterization of titanium-doped barium ferrite (BFTO) nanopowders. BFTO powders with compositions of BaFe(12-x)TixO19, where x=0.32 and x=0.36, were synthesized using a sol-gel method. The powders were characterized using XRD, SEM, and FTIR. XRD analysis confirmed the formation of a single tetragonal phase and particle sizes ranging from 15-50 nm. SEM images showed irregularly shaped plate-like particles 10-40 nm in size. FTIR spectra exhibited peaks corresponding to metal-oxygen bonds and residual organic groups from the synthesis method.
This document provides background information on analytical methods for determining bisphenol A (BPA) levels in food and biological samples. It discusses sample preparation techniques like solvent extraction and solid-phase extraction. It also covers separation and detection methods like liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Finally, it notes that validated analytical methods are available for reliably measuring free and total BPA levels in foods and some biological samples, though validation is limited for conjugated BPA levels in biological samples. Care must still be taken to avoid cross-contamination during sampling and analysis.
IJERD(www.ijerd.com)International Journal of Engineering Research and Develop...IJERD Editor
1. The document summarizes research on synthesizing an infrared transparent glass based on descriptions in an ancient Indian text called AMSHUBODHINI. Raw materials were mixed in ratios specified in the text and melted to produce a non-hygroscopic greenish-yellow calcium glass.
2. Characterization of the glass found it to be transparent in the infrared wavelength range of 5000 to 1200 cm-1, comparable to calcium fluoride glass. Unlike other infrared transparent materials which are hygroscopic, this glass was found to be non-hygroscopic.
3. The research successfully produced an infrared transparent glass from ancient text specifications. The glass has potential infrared applications and advantages over other materials due to its
This document discusses research into using different methods to create co-crystals of active pharmaceutical ingredients (APIs). It focuses on attempts to form co-crystals of caffeine and theophylline through various crystallization routes, including milling, solution growth, and grinding with solvents. Differential scanning calorimetry and X-ray diffraction analysis found that while a sharp melting peak appeared around 202°C for samples, no new co-crystal phase was produced and the samples consisted of just physical mixtures of the original components. A binary phase diagram also supported the lack of co-crystallization.
This document provides an outline for a paper on hydroxyapatite (HAp), including an introduction to HAp and why it is important, the chemistry of HAp, techniques for producing and processing HAp powder, and areas for future research. Specifically, it discusses that HAp is widely used in bioceramics due to its bioactivity and stability, outlines several techniques for producing HAp powder including hydrothermal, sol-gel, and microwave irradiation methods, and indicates that future research opportunities include developing new biomaterials that more closely mimic the structure and properties of natural bone and teeth.
The paper presents an overview of nucleating agents and their effects on crystallization rate, mechanical properties, and thermal properties in polypropylene. Presented at the SPE Automotive TPO Engineered Polyolefins Global Conference, October 2002, while working at Ciba Specialty Chemicals.
This document evaluates the pozzolanic reactivity of calcined kaolinite clay. Various characterization techniques were used to analyze structural changes during calcination, including XRD, thermal analysis, and NMR. The results showed the kaolinite transformed from crystalline to amorphous phases with increasing calcination temperature. Pozzolanic reactivity, as measured by the Chapelle test, was highest for samples calcined at 600-750°C, indicating these have potential as cement additives.
This document discusses the development and optimization of mix designs for low calcium fly ash and slag based geopolymer concrete of grades G30 and G50, equivalent to conventional concrete grades of M30 and M50. The mix designs were developed based on parameters such as alkaline liquid to fly ash ratio, sodium silicate to sodium hydroxide ratio, sodium hydroxide molarity, curing method, temperature, and curing time. Specimens were cast and tested according to code procedures at 3, 7, and 28 days to evaluate compressive strength. An optimum mix design was selected for each grade based on a comparative study of the compressive strength results for the different parameters.
Graphene oxide grafted with iridium complex as a superior heterogeneous catal...Pawan Kumar
A novel graphene oxide (GO)-immobilized heteroleptic iridium complex was synthesized and demonstrated
as a first heterogenized homogeneous catalyst for the production of dimethylformamide (DMF)
from carbon dioxide, hydrogen, and dimethylamine. The synthesized hybrid catalyst showed comparable
activity as homogeneous heteroleptic iridium complex with additional benefits such as facile recovery
and recycling of the catalyst. After completion of the reaction, the heterogeneous catalyst was easily
recovered by filtration, and reused for subsequent recycling processes without any significant change in
the catalytic efficiency
Graphene oxide grafted with iridium complex as a superior heterogeneous catal...Pawan Kumar
A novel graphene oxide (GO)-immobilized heteroleptic iridium complex was synthesized and demonstrated
as a first heterogenized homogeneous catalyst for the production of dimethylformamide (DMF)
from carbon dioxide, hydrogen, and dimethylamine. The synthesized hybrid catalyst showed comparable
activity as homogeneous heteroleptic iridium complex with additional benefits such as facile recovery
and recycling of the catalyst. After completion of the reaction, the heterogeneous catalyst was easily
recovered by filtration, and reused for subsequent recycling processes without any significant change in
the catalytic efficiency.
Graphene oxide grafted with iridium complex as a superior heterogeneous catal...Pawan Kumar
A novel graphene oxide (GO)-immobilized heteroleptic iridium complex was synthesized and demonstrated
as a first heterogenized homogeneous catalyst for the production of dimethylformamide (DMF)
from carbon dioxide, hydrogen, and dimethylamine. The synthesized hybrid catalyst showed comparable
activity as homogeneous heteroleptic iridium complex with additional benefits such as facile recovery
and recycling of the catalyst. After completion of the reaction, the heterogeneous catalyst was easily
recovered by filtration, and reused for subsequent recycling processes without any significant change in
the catalytic efficiency.
ACETYLATION OF BENZYLIC ALCOHOLS OVER BiFeO3 (BFO), Bi0.86Sm0.07Eu0.07FeO3 (B...EDITOR IJCRCPS
BiFeO3 (BFO), Bi0.86Sm0.07Eu0.07FeO3 (BSEFO), and Bi0.86Sm0.07Cd0.07FeO3 (BSCFO) nanopowders were prepared by the sol-gel
combustion method and the catalytic performances were evaluated in acetylation reaction of benzyl alcohol. The physical chemical
properties of catalysts were characterized by using XRD, FT-IR, scanning electron microscope (SEM), EDX and BET surface.
Efficient acetylation of benzyl alcohol was carried out over all the nano powders using acetyl chloride/ acetonitrile at room
temperature. Among the nanopowders, BSCFO showed the highest catalytic performance and the yield of benzyl acetate was 89,
45, and 69 percent over BSCFO, BFO, and BSEFO, respectively. Partial substitution of Sm-Eu and Sm-Cd in bismuth ferrite
improved the catalytic performance and increased the specific surface area of the catalysts. A direct relationship was resulted
between catalytic performance and surface of catalysts, where BSCFO with the highest surface area (111m2/g) exhibited the
superior catalytic performance. The quantitative yield for acetate product was also resulted for acetylation of p-methyl benzyl
alcohol, p-nitro benzyl alcohol and p-chloro benzyl alcohol on BSCFO. The catalysts showed good reusability in the process. The
study confirmed the catalysts could be promising catalyst for acetylation of alcohols.
Keywords: Europium, Samarium, Bismuth ferrites, nano perovskite, doping, Acetylation, benzylic alcohols.
A facile route for nitrogen doped hollow graphitic carbonumarkhalid532
1) A facile route is presented for synthesizing nitrogen-doped hollow graphitic carbon spheres (NHGCSs) through the direct pyrolysis of solid melamine–formaldehyde (MF) resin spheres.
2) The MF resin spheres are prepared via a hydrothermal method without templates or catalysts, and pyrolyzed at temperatures above 400°C to form hollow carbon spheres with graphitic carbon shells.
3) The NHGCSs exhibit excellent capacitive performance as electrode materials for supercapacitors, achieving a high specific capacitance of 306 Fg-1 at 0.1 A g-1.
Surfactant-assisted Hydrothermal Synthesis of Ceria-Zirconia Nanostructured M...IOSR Journals
CeO2–ZrO2 oxides were prepared by the surfactant-templated method using cetyl trimethyl ammonium bromide (CTAB) as template and modified with chromium nitrate. These were characterized by XRD, FT-IR, TEM, SEM, BET and TPD-CO2. The XRD data showed that as prepared CeO2-ZrO2 powder particles have single phase cubic fluorite structure. HRTEM shows mesoscopic ordering. Average particle size is 12-13 nm as calculated from particle histogram. The nitrogen adsorption/desorption isotherm were classified to be type IV isotherm, typical of mesoporous material. The presence of uni-modal mesopores are confirmed by the pore size distribution which shows pore distribution at around 60 A°. Catalytic activity was studied towards liquid-phase oxidation of benzene.
This document describes the synthesis and characterization of novel polybenzoxazine-nanotitania hybrid nanocomposites. The nanocomposites were synthesized using a maleimido terminal benzoxazine monomer and nanotitania through an in-situ sol-gel method. Fourier transform infrared spectroscopy confirmed the formation of nanotitania networks in the hybrid nanocomposites. The introduction of nanotitania particles increased the glass transition temperature and improved the thermal stability and char yield of the polybenzoxazine. Transmission electron microscopy and scanning electron microscopy were used to image the molecular level dispersion and distribution of nanotitania particles in the polybenzoxazine matrices.
Bczt ceramics prepared from activated powdersBéchir Yahmadi
Ultra-fine BayCa1-y(ZrxTi1-x)O3 powders were synthesized via solid state reaction using high-energy ball milling. Dense ceramics were prepared by varying sintering conditions of pressed powders calcined at 800°C. XRD and SEM analysis showed the powders crystallized to a single BCZT phase above 1100°C. Ceramics sintered at 1400°C for 2 hours exhibited maximum density and grain growth with dielectric constant 4 times greater than samples sintered at 1250°C. Ferroelectric hysteresis loops measured the remanent polarization to be 5.7 μC/cm2 and coercive field to be 3.
Facile fabrication and characterizations of nanostructured Fe2O3-TiO2 composi...IJAEMSJORNAL
Fe2O3-TiO2 nanoparticles promises as a highly effective material for adsorption of heavy metals and used as photocatalyst for the removal of organic dye pollutants. In this study, nanostructured Fe2O3-TiO2 composite was successfully fabricated by one-step reaction of ilmenite ore at the high temperature in ambient condition. The resultant Fe2O3-TiO2 composite was characterized by using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherm. The effects of sintered temperature and time on the formation of the Fe2O3-TiO2 nanocomposite were investigated in detail. The Fe2O3-TiO2 was formed from ilmenite ore after calcination at the temperature of 700oC in 3 hours, followed by a ball-milled process in 4 hours. The obtained Fe2O3-TiO2 composite has an average diameter of from 50 - 100 nm with the BET surface area of 7 m2/g.
Physical and Magnetic Properties of Manganese Ferrite NanoparticlesIJERA Editor
In this paper, manganese ferrite (MnFe2O4) nanoparticles were synthesized using chemical bath deposition (CBD) method and characterized by XRD and TEM to determine different properties of nanoparticles. The results obtained showed the formation of manganese ferrite nanoparticles with an average particle size are in good agreement with previous reported experimental results and displayed good magnetic properties. Magnetic properties was determined using Vibrating Sample Magnetometer(VSM). Due to simplicity and low cost of this process, it could be used for synthesis of ferrites nanoparticles. These materials may be used in drug delivery systems, electronic devices and water remediation.
Synthesis and optimisation of ir o2 electrocatalysts by adams fusion method f...tshankar20134
The document summarizes research into optimizing IrO2 as an electrocatalyst for oxygen evolution in solid polymer electrolyte electrolyzers. IrO2 was synthesized using the Adams fusion method, varying synthesis duration from 0.5-4 hours and temperature from 250-500°C. Characterization showed that increasing duration and temperature increased crystallinity and particle size. Electrochemical testing found that IrO2 synthesized for 2 hours at 350°C had the best catalytic activity for oxygen evolution, outperforming a commercial IrO2. Higher temperatures favored formation of the active IrO2 phase but also led to larger particle sizes which decreased activity. Lower than 350°C did not favor IrO2 formation.
Simple and Effective Method of the Synthesis of Nanosized Fe2O 3particlesIOSR Journals
Abstract: Nanosized Iron oxide is prepared by using precipitation method from iron nitrate and liquid ammonia. Thermal analysis shows that synthesized iron oxide shows some weight loss and oxide undergoing decomposition, dehydration or any physical change from TGA curve we observe that Iron oxide shows stable weight loss above 4000C. In DTA curve also, there is exothermic and endothermic peak. Which shows phase transition, solid state reaction or any chemical reaction occurred during heating treatment. Morphology is observed by scanning electron microscopy (SEM) shows particles are nanosized. Further morphology observation by Transmission Electron Microscopy (TEM) revels that Iron Oxide has the corundum (Al2O3) structure. Magnetic measurements shows that iron oxide has five unpaired electron and strongly paramagnetic character.
The document describes the preparation of SnO2/C biomorphic materials through a biotemplating process using ramie fibers. Specifically:
- Ramie fibers were impregnated with Sn(OH)4 sol using ultrasonic treatment and then sintered under vacuum at temperatures from 480-630°C for 20-60 minutes to produce SnO2/C composites.
- Characterization showed the sintering temperature and holding time affected the crystal structure, morphology, and composition of the final materials. SnO2 formed from the decomposition of Sn(OH)4 at around 345°C.
- When sintered at 630°C, SnO was also observed forming through
375
Temperature (°C)
Figure 7: The effects of calcination treatment of diatomite on DME selectivity via methanol
dehydration over fresh DM and DM500 catalysts at the reaction temperature from 250 to 350°C
1. The document investigates the effects of calcination treatment of diatomite catalysts on dimethyl ether (DME) synthesis from methanol.
2. Calcining diatomite at 500°C (DM500) increased its BET surface area but decreased its organic content compared to fresh diatomite (DM).
3. While calcination had little effect on methanol conversion rates, DM500 exhibited higher DME selectivity than fresh DM due
The document summarizes research on fluoridating and sintering hydroxyapatite material and measuring its resulting mechanical properties. Hydroxyapatite samples were prepared using a sol-gel technique with the addition of aluminum isopropoxide and teflon powder. The samples were then sintered at various temperatures between 1200-1460°C. Characterization of the sintered samples found they consisted of fluoridated hydroxyapatite crystals. Mechanical testing found that as sintering temperature increased, grain size increased up to 18.76 micrometers, while density and mechanical properties like hardness decreased. Sintering at 1250°C produced samples with the highest hardness and strength.
This document summarizes research evaluating Pt/GMC and Pt/rGO electrocatalysts for electro-oxidation of methanol. Graphitic mesoporous carbon (GMC) and reduced graphene oxide (rGO) were synthesized and used to support platinum nanoparticles. The materials were characterized using various techniques and their electrocatalytic performance for methanol oxidation was measured via cyclic voltammetry. The results showed that Pt/GMC exhibited the highest mass activity and best resistance to carbon monoxide poisoning compared to Pt/rGO and a commercial Pt/C catalyst. Therefore, Pt/GMC demonstrated the best electrocatalytic performance for methanol electrooxidation.
Sonocatalytic Performance of Fe3O4 Cluster Microspheres Gratiphic Carbon Comp...ijtsrd
Fe3O4 g C3N4 composite was synthesized using hydrothermal simple and facile techniques. The sonocatalytic activity of the magnetic Fe3O4 g C3N4 composite was studied through the H2O2 assisted system for degradation of water soluble organic pollutants such as methylene blue MB , rhodamine B RhB and methyl orange MO . X ray diffraction XRD and scanning electron microscopy SEM equipped were employed for the characterizing the structure and morphology of the so synthesized nanohybrid. The integration of H2O2 and catalyst dosage enhaced the sonocatalytic degradation of dyes. Furthermore, the magnetic property of the sample leaded to easier separation of the microhybrid, made it recyclable with a negligible decline in the dye degradation even after four consecutive recycles. Xuan Sang Nguyen "Sonocatalytic Performance of Fe3O4 Cluster Microspheres/Gratiphic Carbon Composite for Efficient Degradation of Organic Dyes" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-7 | Issue-3 , June 2023, URL: https://www.ijtsrd.com.com/papers/ijtsrd57418.pdf Paper URL: https://www.ijtsrd.com.com/chemistry/environmental-chemistry/57418/sonocatalytic-performance-of-fe3o4-cluster-microspheresgratiphic-carbon-composite-for-efficient-degradation-of-organic-dyes/xuan-sang-nguyen
The document discusses the performance and characteristics of fly ash-based geopolymer concrete with and without manufactured sand. It presents a mix design procedure for geopolymer concrete and experimental results showing that geopolymer concrete can achieve compressive strengths up to 68% higher than conventional concrete. The study demonstrates that high alkali-activated fly ash mixtures can be used as a cementitious material and provides guidelines for designing geopolymer concrete mixes.
Phase Transformations and Thermodynamics in the System Fe2О3– V2О5 – MnО – Si...IJERA Editor
Thermodynamic characteristics in the system Fe2O3 – MnO – V2O5 –SiO2 have been investigated. Two mixtures
have been prepared. The first mixture was synthetic, prepared from pure oxides in proportion according to the
chemical composition of the waste catalyst and manganese concentrate. The second one contained the waste
vanadium catalyst and manganese concentrate. The synthetic mixture has been used as a standard in order to
establish the influence of impurities in the concentrate, and the waste catalyst on the thermodynamics of the
studied system.
Experiments carried out in the temperature up to 1473 K for the system containing waste vanadium catalyst and
manganese concentrate occur to formation of new phases formation as FeV2O4 and Iron Vanadium Oxide type
and Jacobsite types MnFe2O4 and (Mn6Fe4)(Mn4Fe1.6)O4. EMF method with difference reference electrode
(Ni/NiO, Mo/MoO2 and air) relationship of delta GoT = f(T) in the temperature range 1073 – 1173 К of mixtures
was obtained. The experimental data for the system show that the reference electrodes air and Ni/NiO are more
suitable than Mo/MoO2.
The obtained results will be used as an investigations base to the production of complex iron vanadium
manganese alloy using the waste materials.
The document summarizes research on upgrading metallurgical-grade silicon from aluminum-silicon alloys produced by aluminothermic reduction of Egyptian sand. Key points:
1) Aluminum-silicon alloys were leached with hydrochloric acid to produce silicon powder and an aluminum chloride solution. Nearly pure (99.3%) silicon was obtained by optimizing particle size, temperature, time, solid/liquid ratio, and acid concentration.
2) Process parameters like temperature, time, acid concentration, and liquid/solid ratio were studied to determine their effect on aluminum removal efficiency. Near complete removal was achieved at 50°C, 20 minutes, 6.24M HCl concentration, and 9:
1) Researchers successfully produced SiAlON ceramics from industrial wastes like silicon sludge and aluminum dross using a nitriding combustion process.
2) The nitriding combustion process allows synthesis of ceramic powders in an energy efficient way while recycling wastes.
3) Specifically, the process was used to synthesize SiAlON powders from silicon sludge generated in silicon wafer production and from aluminum dross from aluminum smelting. Desert sand was also used to synthesize silicon oxynitride powder.
This document summarizes research on enhancing the thermal conductivity of polymer composites by filling them with three-dimensional (3D) brushlike aluminum nitride (AlN) nanowhiskers. The 3D brushlike AlN nanowhiskers were synthesized using a simple combustion method. Polymer composites filled with 47% by volume of the 3D brushlike AlN nanowhiskers achieved a thermal conductivity of 4.2 W/m-K, which was over 2 times higher than composites filled with the same amount of commercial equiaxed AlN particles. The enhanced thermal conductivity is attributed to the 3D brushlike nanowhiskers promoting a more effective percolating network with
The document describes a novel method for growing aluminium nitride (AlN) nanowires. Specifically:
1) AlN nanowires were grown by nitridating a mixture of aluminium and ammonium chloride powders at 1000°C for 1 hour under flowing nitrogen gas.
2) SEM images showed the production of homogeneous AlN nanowires between 40-150nm in diameter without droplets at the tips, suggesting vapor-phase growth.
3) A thermodynamic analysis supported that the nanowires were grown via spontaneous vapor-phase chlorination and nitridation reactions of intermediate species produced from the aluminium, ammonium chloride and nitrogen.
This document describes research into producing crack-free functionally graded materials (FGMs) composed of stainless steel 316L and alumina through spark plasma sintering (SPS). Initial experiments studied sintering the individual powders and their composites to determine optimal SPS conditions that yielded high density. Subsequent experiments fabricated FGM pellets with varying numbers of interlayers but still encountered cracking near alumina-rich layers. Adding yttrium-stabilized zirconia to the interlayers helped reduce cracking by lowering residual stresses. A crack-free FGM pellet was successfully produced using 19 interlayers between the stainless steel and alumina ends, with the hardness varying steadily throughout the gradient.
This document summarizes research on spark plasma sintering (SPS) of tungsten carbide (WC) and cemented carbides. SPS allows for faster sintering times compared to conventional methods, enabling better control of WC grain size growth. Studies have shown SPS can produce fully dense WC materials with nano-sized or sub-micron WC grains and hardness values up to 28 GPa. SPS of WC-Co powders can achieve high density at temperatures as low as 1050-1100°C, retaining initial nano/sub-micron grain sizes better than conventional sintering. However, truly nano-scale WC grain sizes below 100nm have not been achieved
This document describes a new synthesis route for producing dense silicon oxynitride (Si2N2O) ceramics using desert sand as the raw material. The process involves:
1. Combusting a mixture of desert sand and silicon metal under pressurized nitrogen via self-propagating high-temperature synthesis to produce pure Si2N2O powder.
2. Densifying the Si2N2O powder via spark plasma sintering with 5 wt.% calcia-alumina additive to achieve 99% theoretical density in only 6 minutes of heating and holding.
3. The resulting dense Si2N2O ceramic exhibits a Vickers hardness of 18.7 GPa, fracture tough
Quasi-aligned aluminum nitride (AlN) nanofibers were formed through a nitriding combustion synthesis reaction using aluminum and aluminum nitride powders with yttria and ammonium chloride additives. Scanning electron microscope images showed the aluminum particles maintained their original ball-like shape after combustion, with a thin crust layer on the surface covering quasi-aligned AlN nanofibers grown in the interior. This novel morphology is believed to form through a two-stage process where the crust acts as a micro-reactor allowing nitridation and fiber growth inside the molten aluminum core.
The document describes a novel method for growing aluminium nitride (AlN) whiskers through the direct nitridation of an Al-NH4Cl mixture. NH4Cl promotes the growth of AlN whiskers through a vapor-phase reaction mechanism rather than the normal liquid-gas mechanism. Thermodynamic analysis confirms that AlN whiskers can grow via spontaneous chlorination-nitridation reactions in the vapor phase. The addition of NH4Cl not only enhances the nitridation reaction but also enables the production of homogeneous AlN nanowhiskers less than 150 nm in diameter.
2. M. Radwan et al. / Journal of Materials Processing Technology 181 (2007) 106–109 107
Table 1
XRD results of products obtained from precursors with different Fe3+/Ba2+ mole ratio and calcined for 2 h at 800–1200 ◦C (no surfactants used)
Fe3+/Ba2+ Phases obtained as deduced by XRD
800 ◦C 1000 ◦C 1200 ◦C
12 BaFe0.24Fe0.76O2.88 > BaFe12O19 > Fe2O3 (122.1)a BaFe12O19 > Fe2O3 BaFe0.24Fe0.76O2.88 (140) BaFe12O19 Fe2O3 (191.2)
10.9 BaFe12O19 > Fe2O3 > BaFe0.24Fe0.76O2.88 (143.8) BaFe12O19 Fe2O3 BaO2 (185) BaFe12O19 (191.1)
9.23 Fe2O3 > BaFe12O19 > Ba2Fe6O11 > BaFe0.24Fe0.76O2.88
(98.8)
BaFe12O19 > Fe2O3 BaO2 Ba2Fe6O11 (174.7) BaFe12O19 Ba2Fe6O11 (221.4)
8 BaFe12O19 Fe2O3 (153.1) BaFe12O19 (151) BaFe12O19 (200.6)
a Crystallite size (nm) of BaFe12O19 phase as calculated from XRD results using classic Scherrer formula.
precursors (reddish solids) were heated (calcined) at a rate of 10 ◦C/min in static
air atmosphere up to different temperatures (800, 1000 and 1200 ◦C) where they
were maintained for 2 h. The effect of surface active agents on the formation of
BaFe12O19 was studied by addition of 1000 ppm of the surfactant (CTAB, SDS
or Triton X-100) to the mixed Fe/Ba solution before the precipitation step.
The calcined powders were ground gently by agate mortar prior to their
characterization. The crystalline phases present in the different calcined samples
were identified by X-ray diffraction (XRD) on a Bruker axis D8 diffractometer
using Cu K␣ radiation. The average crystallite size of the powders was estimated
automatically from corresponding XRD data (using X-ray line-broadening tech-
nique employing the classical Scherrer formula). The particles morphologies
were observed by scanning electron microscopy (SEM, JSM-5400). The mag-
netic properties of different calcined powders were measured at room temper-
ature on a vibrating sample magnetometer (VSM, model LDJ 9600-1, USA)
in a maximum applied field of 15 kOe. From the obtained hysteresis loops, the
saturation magnetization (Ms) and coercivity (Hc) were determined.
3. Results and discussion
The effect of Fe3+/Ba2+ mole ratio and calcination temper-
ature on the phase composition of products has been followed
by the XRD analyses. The results obtained are listed in Table 1.
It can be observed that the stoichiometric ratio was not appro-
priate to result in a single phase barium hexaferrite powder and
decreasing the Fe3+/Ba2+ mole ratio (i.e. increasing the Ba con-
centration) promotes the formation of barium hexaferrite phase
at the various thermal treatments. At low calcination temperature
of 800 ◦C, the hematite Fe2O3 phase impurity was found in all
samples. The intermediate BaFe0.24Fe0.76O2.88 phase appears
as a major phase at the stoichiometric sample and its concen-
tration decreases as the Fe3+/Ba2+ mole ratio decreases to 9.23
and disappears at 8. The phases obtained from precursors with
Fe3+/Ba2+ mole ratio of 9.23 were rather complicated in con-
trast to other starting ratios, the hematite became the major phase
and another stable ferrite phase (Ba2Fe6O11) was remained in
the calcined powders even after heating at 1000 and 1200 ◦C.
Increasing the calcination temperature to 1000 ◦C enhanced
the formation of barium hexaferrite phase and a single phase
BaFe12O19 powder was formed at the Fe3+/Ba2+ mole ratio of
8. The intermediate hematite phase was obtained in other start-
ing ratios. But the BaFe0.24Fe0.76O2.88 phase disappeared by
decreasing the Fe3+/Ba2+ mole ratio below the stoichiometric
value. An intermediate barium oxide (BaO2) phase was detected
in the powders with the starting ratios of 10.9 and 9.23.
At the high calcination temperature (1200 ◦C), Fe2O3 was
obtained only in the stoichiometric mixture and single phase
barium hexaferrite powders were obtained from precursors with
starting mole ratios of 10.9 and 8.
The crystallite size of formed single phase barium hexaferrite
powdersascalculatedfromXRDanalysesusingDebye-Scherrer
formula was in the range of 151–200 nm.
The SEM micrograph of single phase barium hexaferrite
powder obtained from starting mixture with the ratio of 8 and
heating at 1000 ◦C is shown in Fig. 1. The powder consists
of micro-aggregates with ultrafine particles mostly of platelet
shape, more longitudinal, with mean diameters (≤200 nm).
The effect of surfactants on the formation and properties
of barium hexaferrite powders was studied by the addition of
a 1000 ppm surfactant to the cations mixture (with Fe3+/Ba2+
mole ratio of 8) prior to the co-precipitation step. Three dif-
ferent surfactants were experimented; CTAB, SDS and Triton
X-100. The dry precursors were then calcined at 800, 1000 and
1200 ◦C for 2 h. The XRD analyses of various calcined samples
revealed the formation of only single phase barium hexaferrite
powders. Fig. 2 gives the XRD pattern of Bafe12O19 obtained
after calcination at 800 ◦C when CTAB was used as the sur-
factant. The pattern shows well-defined Bragg peaks which is
significant of a good crystalline state of the sample. Fig. 3 shows
the effect of various surfactants and calcination temperatures
on the crystallite size of obtained powders. It can be observed
that the addition of surfactants before the co-precipitation step
could prevent agglomeration of particles and grain growth dur-
ing calcination course, which leads to the decrease of grain size
and formation of nanocrystalline single phase barium hexaferrite
powders.
The SEM micrographs of different powders obtained by each
surfactant are given in Fig. 4(a–d). It can be observed that the
Fig. 1. SEM micrograph of obtained single phase BaFe12O19 powder
(Fe3+/Ba2+ = 8, calcination temperature = 1000 ◦C).
3. 108 M. Radwan et al. / Journal of Materials Processing Technology 181 (2007) 106–109
Fig. 2. XRD pattern of BaFe12O19 obtained from a precursor with Fe3+/Ba2+
mole ratio of 8 and calcined for 2 h at 800 ◦C (with CTAB surfactant).
surfactants can control the microstructure of formed barium hex-
aferrite powders. When the anionic surfactant SDS was used,
the 800 ◦C calcined hexaferrite powders (Fig. 4a) had well-
arranged grains with homogeneous nanometer size (∼100 nm).
We think that some kind of repulsion between negative surfac-
tant anions and molecules of Ba and Fe chlorides or hydroxides
existed which prevented the agglomeration of particles dur-
ing the heating step. The nucleation of hexaferrite particles
was homogeneous and the grain growth was hindered which
resulted in good size homogeneity. The cationic CTAB surfac-
Fig. 3. Effect of surfactants and calcination temperature on crystallite size (nm)
of formed BaFe12O19 obtained from precursors with Fe3+/Ba2+ = 8.
tant was found to make the barium hexaferrite particles arranged
in laminates-structure like or clusters which include very small
particles of nanometer size (Fig. 4b). We think that an attraction
forces existed between CTAB cationic surfactant and molecules
of barium and ferric chlorides. When NaOH was added, the bar-
ium and ferric hydroxides molecules were co-precipitated and
arranged in some way in laminates like structure. Increasing the
calcination temperature (to 1200 ◦C) led to the coarsening of
these laminates to few tenths of microns (Fig. 4c). Since Triton
X-100 is non-ionic surfactant, such electrostatic forces are not
exist and less localization of surfactant on interfacial surfaces of
Fig. 4. Effect of surfactants additions on microstructure of synthesized BaFe12O19 powders obtained from precursors with Fe3+/Ba2+ mole ratio = 8: (a) using SDS
and calcined at 800 ◦C, (b) using CTAB and calcined at 800 ◦C, (c) using CTAB and calcined at 1200 ◦C and (d) using X-100 and calcined at 800 ◦C.
4. M. Radwan et al. / Journal of Materials Processing Technology 181 (2007) 106–109 109
Table 2
Magnetic properties of single phase BaFe12O19 powders (Hc and Bs were mea-
sured at room temperature under Hmax = 15 kOe)
Preparation conditions Magnetic properties
Fe3+/Ba2+ Surfactant Calcination
temperature (◦C)
Hc (Oe) Ms (emu/g)
10.9 – 1200 2556 44.9
8 – 1000 3923 28.8
8 – 1200 1670 44.12
8 CTAB 800 4347 45.13
8 CTAB 1000 4358 46.65
8 CTAB 1200 669.9 49.85
8 SDS 800 4518 46.66
8 SDS 1000 4327 45.29
8 SDS 1200 976.6 50.02
8 X-100 800 2050 47.22
8 X-100 1000 4580 46.84
8 X-100 1200 642.4 49.81
barium and ferric molecules was found. On the calcination, the
nucleation and growth of hexaferrite particles were inhomoge-
neous which led to a microstructure with various morphologies
of irregular shapes (Fig. 4d).
The magnetization curves of different powders of single
phase barium hexaferrite were measured at room temperature
under an applied field of 15 kOe. The results of magnetic prop-
erties Hc and Ms are summarized in Table 2. In general, as
commonly observed in the case of ultrafine particles, the sat-
uration magnetization values are lower than the theoretical sat-
uration magnetization for single crystals of barium hexaferrite
(Bs = 72 emu/g) as reported by Shirk and Buessem. Also, the val-
ues of intrinsic coercivity Hc obtained for our samples are lower
than theoretical calculations (Hc ≈ 6700 Oe) using the Stoner
and Wohlfarth model of single-domain particles [2]. Various
theories, including surface area, spin canting and sample inho-
mogeneity have been proposed to account for the relatively low
magnetization in fine particles [15]. It may also be due the pres-
ence of superparamagnetic fractions of very fine particles in the
formed ferrite nanopowders.
4. Conclusions
The observations from the XRD, SEM and VSM studies are
summarized as follows:
(i) A barium surplus is important to synthesize single phase
BaFe12O19 powder by chemical co-precipitation method.
Pure ultrafine barium hexaferrite powders (150–200 nm)
were obtained from precursors with Fe3+/Ba2+ mole ratio
of 8 after calcination at temperatures ≥1000 ◦C for 2 h in
static air atmosphere.
(ii) The addition of surfactants to the starting solution of barium
and ferric cations (Fe3+/Ba2+ = 8) before co-precipitation
step was found to enhance the formation of single phase
barium hexaferrite powders at low calcination temperature
of 800 ◦C.
(iii) The surfactant addition controls the microstructure of
formed barium hexaferrite powders. The anionic SDS sur-
factant led to the formation of well-arranged barium hex-
aferrite grains with homogeneous nanometer sizes. The
cationic CTAB surfactant resulted in micrometer sized lam-
inates or clusters like containing ultrafine individual barium
hexaferrite particles. The non-ionic Triton X-100 surfac-
tant produced nano-size hexaferrite particles with irregular
shapes.
(iv) The formed nano-sized barium hexaferrite powders had
good magnetic saturations (50.02 emu/g) and wide intrinsic
coercivities (642.4–4580 Oe).
References
[1] http://www.aacg.bham.ac.uk/magnetic materials/.
[2] V. Pillai, P. Kumar, M.S. Multani, D.O. Shah, Colloids Surf. A: Physic-
ochem Eng. Aspects 80 (1993) 69.
[3] S. Castro, M. Gayoso, C. Rodr´ıguez, J. Mira, J. Rivas, S. Paz, J.M.
Gren`eche, J. Magn. Magn. Mater. 140–144 (1995) 2097.
[4] M.V. Cabaˇnas, J.M. Gonz´alez-Calbet, Solid State Ionics 63–65 (1993) 207.
[5] S.E. Jacobo, L. Civale, C. Domingo-Pascual, R. Rodrigues-Clements, M.A.
Blesa, J. Mater. Sci. 32 (1997) 1025.
[6] O. Carp, R. Barjega, E. Segal, M. Brezeanu, Thermochim. Acta 318 (1998)
57.
[7] T. Ogasawara, M.A.S. Oliveira, J. Magn. Magn. Mater. 217 (2000) 147.
[8] J. Matutes-Aquino, S. D´ıaz-Castaˇn´on, M. Mirabal-Garc´ıa, S.A. Palomares-
S´anchez, Scripta Mater. 42 (2000) 295.
[9] M.-L. Wang, Z.W. Shih, C.-H. Lin, J. Cryst. Growth 130 (1993) 153.
[10] X. Liu, J. Wang, L.-M. Gan, S.-C. Ng, J. Magn. Magn. Mater. 195 (1999)
452.
[11] D. Mishra, S. Anand, R.K. Panda, R.P. Das, Mater. Chem. Phys. 86 (2004)
132.
[12] C. S¨urig, K.A. Hempel, Ch. Sauer, J. Magn. Magn. Mater. 157–158 (1996)
268.
[13] W. Zhong, W. Ding, N. Zhang, J. Hong, Q. Yan, Y. Du, J. Magn. Magn.
Mater. 168 (1997) 196.
[14] R.M. Garcia, E.R. Ruiz, E.E. Rams, R.M. Sanchez, J. Magn. Magn. Mater.
223 (2001) 133.
[15] V.K. Sankaranarayanan, D.C. Khan, J. Magn. Magn. Mater. 153 (1996)
337.
[16] M. El-Hilo, H. Pfeiffer, K. O’Grady, W. Sch¨uppel, E. Sinn, P. G¨ornert, M.
R¨osler, D.P.E. Dickson, R.W. Chantrell, J. Magn. Magn. Mater. 129 (1994)
339.
[17] K.V.P.M. Shafi, A. Gedanken, Nanostructured Mater. 12 (1999) 29.
[18] O. Abe, M. Narita, Solid State Ionics 101–103 (1997) 103.