scholarly journals Novel Magnetic Inorganic Composites: Synthesis and Characterization

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1284
Author(s):  
Marco Natali ◽  
Sergio Tamburini ◽  
Roberta Bertani ◽  
Daniele Desideri ◽  
Mirto Mozzon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Particles ◽  
Solidification Process ◽  
Chloride Ions ◽  
Electrical Measurements ◽  
High Concentration ◽  
Practical Applications ◽  
Inorganic Composites ◽  
Similar Content ◽  
Quartz Aggregates

The addition of magnetic particles to inorganic matrices can produce new composites exhibiting intriguing properties for practical applications. It has been previously reported that the addition of magnetite to concrete improves its mechanical properties and durability in terms of water and chloride ions absorption. Here we describe the preparation of novel magnetic geopolymers based on two different matrices (G1 without inert aggregates and G2 with inert quartz aggregates) containing commercial SrFe12O19 particles with two weight concentrations, 6% and 11%. The composites’ characterization, including chemical, structural, morphological, and mechanical determinations together with magnetic and electrical measurements, was carried out. The magnetic study revealed that, on average, the SrFe12O19 magnetic particles can be relatively well dispersed in the inorganic matrix. A substantial increase in the composite samples’ remanent magnetization was obtained by embedding in the geopolymer SrFe12O19 anisotropic particles at a high concentration under the action of an external magnetic field during the solidification process. The new composites exhibit good mechanical properties (as compressive strength), higher than those reported for high weight concretes bearing a similar content of magnetite. The impedance measurements indicate that the electrical resistance is mainly controlled by the matrix’s chemical composition and can be used to evaluate the geopolymerization degree.

Physico-chemical and mechanical properties of organic-inorganic composites

2015 ◽  
Vol 37 (4) ◽  
pp. 369-374
Author(s):  
G.I. Khovanets’ ◽  
◽  
Y.G. Medvedevskikh ◽  
V.P. Zakordonskiy ◽  
V.V. Kochubey ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Inorganic Composites ◽  
Physico Chemical

MODELING OF THE INFLUENCE OF THERMIC TREATMENT UPON THE MECHANICAL PROPERTIES OF ALUMINUM-TIN ALLOYS

2015 ◽  
Vol 9 (2) ◽  
pp. 2431-2439
Author(s):  
Saad El Madani ◽  
S. ELHAMZI ◽  
J. KATTEN ◽  
A. IBNLFASSI
Keyword(s):  
Mechanical Properties ◽  
Solidification Process ◽  
Tin Alloys ◽  
Homogenization Process ◽  
Fundamental Reason ◽  
Segregation Phenomenon ◽  
Cooling Velocity

In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements. The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Sn, Al2%Sn, Al3%Sn and Al4%Sn, as well as the tin effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical  behavior of such alloys as Al-Sn are directly influenced by some parameters such as composition, cooling velocity and homogenization process.

MODELISATION DE L'INFLUENCE DU TRAITEMENT THERMIQUE SUR LES PROPRIETES MECANIQUES DES ALLIAGES ALUMINIUM-CUIVRE (Al-Cu)

2015 ◽  
Vol 10 (2) ◽  
pp. 2753-2761
Author(s):  
Saad El Madani ◽  
S. ELHAMZI ◽  
A. IBNLFASSI ◽  
L. ZERROUK ◽  
O. BEN LENDA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Solidification Process ◽  
Traitement Thermique ◽  
Homogenization Process ◽  
Fundamental Reason ◽  
Segregation Phenomenon ◽  
Proprietes Mecaniques ◽  
Cooling Velocity ◽  
Copper Effect

In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements.   The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Cu, Al2%Cu, Al3%Cu et Al4%Cu, as well as the copper effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Cu are directly influenced by some parameters such as composition, cooling velocity and homogenization process.

Molecular Characterization of the Surface Excess Charge Layer in Droplets

2020 ◽  
Author(s):  
Victor Kwan ◽  
Styliani Consta
Keyword(s):  
Hydrogen Bonds ◽  
Surface Charge ◽  
Droplet Size ◽  
Chloride Ions ◽  
Total Charge ◽  
Excess Charge ◽  
Surface Excess ◽  
High Concentration ◽  
Dipole Orientation ◽  
Charge Layer

<div>Charged droplets play a central role in native mass spectrometry, atmospheric aerosols and in serving as micro-reactors for accelerating chemical reactions. The surface excess charge layer in droplets has often been associated with distinct chemistry. Using molecular simulations for droplets with Na+ and Cl- ions we have found that this layer is ≈ 1.5−1.7 nm thick and depending on the droplet size it includes 33%-55% of the total number of ions. Here, we examine the effect of droplet size and nature of ions in the structure of the surface excess charge layer by using molecular dynamics. We find that in the presence of simple ions the thickness of the surface excess charge layer is invariant not only with respect to droplet size but also with respect to the nature of the simple ions and it is not sensitive to fine details of different force fields used in our simulations.</div><div> In the presence of macroions the excess surface charge layer may extend to 2.0. nm. For the same droplet size, iodide and model hydronium ions show considerably higher concentration than the sodium and chloride ions. <br></div><div>We also find that differences in the average water dipole orientation in the presence of cations and anions in this layer are reflected in the charge distributions. Within the surface charge layer, the number of hydrogen bonds reduces gradually relative to the droplet interior where the number of hydrogen bonds is on the average 2.9 for droplets of diameter < 4 nm and 3.5 for larger droplets. The decrease in the number of hydrogen bonds from the interior to the surface is less pronounced in larger droplets. In droplets with diameter < 4 nm and high concentration of ions the charge of the ions is not compensated only by the solvent polarization charge but by the total charge that also includes the other free charge. This finding shows exceptions to the commonly made assumption that the solvent compensates the charge of the ions in solvents with very high dielectric constant. The study provides molecular insight into the bi-layer droplet structure assumed in the equilibrium partitioning model of C. Enke and assesses critical assumptions of the Iribarne-Thomson model for the ion-evaporation mechanism. <br></div>

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura &amp; Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

scholarly journals Microstructure and Mechanical Properties of Novel Quasibinary Al-Cu-Yb and Al-Cu-Gd Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 476
Author(s):  
Sayed Amer ◽  
Ruslan Barkov ◽  
Andrey Pozdniakov
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Mechanism Of Action ◽  
Annealing Temperature ◽  
Eutectic Reaction ◽  
Solidification Process ◽  
Annealed State ◽  
Microstructure And Mechanical Properties ◽  
Cold Rolled ◽  
Hot Rolled

Microstructure of Al-Cu-Yb and Al-Cu-Gd alloys at casting, hot-rolled -cold-rolled and annealed state were observed; the effect of annealing on the microstructure was studied, as were the mechanical properties and forming properties of the alloys, and the mechanism of action was explored. Analysis of the solidification process showed that the primary Al solidification is followed by the eutectic reaction. The second Al8Cu4Yb and Al8Cu4Gd phases play an important role as recrystallization inhibitor. The Al3Yb or (Al, Cu)17Yb2 phase inclusions are present in the Al-Cu-Yb alloy at the boundary between the eutectic and aluminum dendrites. The recrystallization starting temperature of the alloys is in the range of 250–350 °C after rolling with previous quenching at 590 and 605 °C for Al-Cu-Yb and Al-Cu-Gd, respectively. The hardness and tensile properties of Al-Cu-Yb and Al-Cu-Gd as-rolled alloys are reduced by increasing the annealing temperature and time. The as-rolled alloys have high mechanical properties: YS = 303 MPa, UTS = 327 MPa and El. = 3.2% for Al-Cu-Yb alloy, while YS = 290 MPa, UTS = 315 MPa and El. = 2.1% for Al-Cu-Gd alloy.

The Structure and Mechanical Properties of Aluminum Cellular Metal With Periodic Cubic Cells

2016 ◽  
Author(s):  
Xiaobing Dang ◽  
Ruxu Du ◽  
Kai He ◽  
Qiyang Zuo
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Sheet Metal ◽  
Light Weight ◽  
Practical Applications ◽  
Sheet Metal Stamping ◽  
High Stiffness ◽  
The Past ◽  
Cellular Metal ◽  
Metal Stamping

As a light-weight material with high stiffness and strength, cellular metal has attracted a lot of attentions in the past two decades. In this paper, the structure and mechanical properties of aluminum cellular metal with periodic cubic cells are studied. The aluminum cellular metal is fabricated by sheet metal stamping and simple adhesion. Two sizes of specimens with cell sizes of 3mm and 5mm are fabricated. Their relative density and mechanical properties are tested by means of experiments. The results show that the cubic-cell cellular metal has high and predictable strength and hence, can be used for many practical applications.

Some Properties of Stratified Composites

2010 ◽  
Author(s):  
Adrian Circiumaru ◽  
Vasile Bria ◽  
Iulian-Gabriel Birsan ◽  
Gabriel Andrei ◽  
Dumitru Dima
Keyword(s):  
Mechanical Properties ◽  
Magnetic Particles ◽  
Bending Strength ◽  
Electric Circuit ◽  
Textile Composites ◽  
Hybrid Technique ◽  
Layer By Layer ◽  
Filled Polymer ◽  
Polymer Layers ◽  
The Right

The multi-component composites could represent the cheapest solution when controllable properties are required. In order to establish the right amount of filler it is necessary to analyze not only the electro-magnetic and mechanical properties but also, the thermal ones. The filler presence in the matrix produces discontinuities at the fibre-matrix interface with consequences regarding mechanical properties. Using a single filler it is possible to improve one or two properties electrical and thermal conductivity for instance and mean time to induce a decrease of other properties as bending strength, shock resistance etc. Using polymer layers with relatively high electrical conductivity as external layers of laminate and magnetic particles filled polymer as core layers. An electric circuit might be, at the same time, the reinforcement of a composite leading to lighter structures and, based on carbon fiber’s properties might transmit information about the material’s loading, temperature or integrity. Fabric reinforced or textile composites are used in aerospace, automotive, naval and other applications. They are convenient material forms providing adequate stiffness and strength in many structures. The microstructure of composite reinforced with woven, braided, or stitched networks is significantly different from that of tape based laminates. The properties of the composite depend not only on the properties of the components but on quality and nature of the interface between the components and its properties. Reinforced composites with filled epoxy matrix were formed using a hybrid technique consisting in layer-by-layer adding of reinforcement sheets into a glass mould. Various distributions of reinforcement sheets and filled polymer layers were realized in order to point out the ways in which the final properties might be controlled. Mechanical properties were analyzed.

Novel vanillic acid-based poly(ether–ester)s: from synthesis to properties

2015 ◽  
Vol 6 (5) ◽  
pp. 797-804 ◽  
Author(s):  
Chengcai Pang ◽  
Jie Zhang ◽  
Qiufen Zhang ◽  
Guolin Wu ◽  
Yinong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vanillic Acid ◽  
Direct Esterification ◽  
Practical Applications ◽  
Ether Ester

Two series of bio-based poly(ether–ester)s prepared from vanillic acid and linear α,ω-diols have been successfully synthesized by the direct esterification method. The mechanical properties of these poly(ether–ester)s are excellent, making them suitable materials for some practical applications.

scholarly journals Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Eduardo Sadot Herrera-Sosa ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera-Díaz ◽  
Epifanio Cruz-Zaragoza
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Chemical Properties ◽  
Plain Concrete ◽  
Cement Matrix ◽  
Portland Cement Concrete ◽  
High Concentration ◽  
Good Tool ◽  
Waste Tire ◽  
Physical And Chemical

In polymer reinforced concrete, the Young’s modulus of both polymers and cement matrix is responsible for the detrimental properties of the concrete, including compressive and tensile strength, as well as stiffness. A novel methodology for solving such problems is based on use of ionizing radiation, which has proven to be a good tool for improvement on physical and chemical properties of several materials including polymers, ceramics, and composites. In this work, particles of 0.85 mm and 2.80 mm obtained from waste tire were submitted at 250 kGy of gamma radiation in order to modify their physicochemical properties and then used as reinforcement in Portland cement concrete for improving mechanical properties. The results show diminution on mechanical properties in both kinds of concrete without (or with) irradiated tire particles with respect to plain concrete. Nevertheless such diminutions (from 2 to 16%) are compensated with the use of high concentration of waste tire particles (30%), which ensures that the concrete will not significantly increase the cost.

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