scholarly journals Optical, Structural, and Dielectric Properties of Composites Based on Thermoplastic Polymers of the Polyolefin and Polyurethane Type and BaTiO3 Nanoparticles

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 753
Author(s):  
M. Baibarac ◽  
A. Nila ◽  
I. Smaranda ◽  
M. Stroe ◽  
L. Stingescu ◽  
...  
Keyword(s):  
Crystallization Process ◽  
Weight Ratio ◽  
Thermoplastic Elastomers ◽  
Visible Spectral Range ◽  
X Ray Diffraction ◽  
Thermoplastic Polymers ◽  
The Matrix ◽  
Free Films ◽  
Batio3 Nanoparticles ◽  
Properties Of Composites

In this work, new films containing composite materials based on blends of thermoplastic polymers of the polyurethane (TPU) and polyolefin (TPO) type, in the absence and presence of BaTiO3 nanoparticles (NPs) with the size smaller 100 nm, were prepared. The vibrational properties of the free films depending on the weight ratio of the two thermoplastic polymers were studied. Our results demonstrate that these films are optically active, with strong, broad, and adjustable photoluminescence by varying the amount of TPU. The crystalline structure of BaTiO3 and the influence of thermoplastic polymers on the crystallization process of these inorganic NPs were determined by X-ray diffraction (XRD) studies. The vibrational changes induced in the thermoplastic polymer’s matrix of the BaTiO3 NPs were showcased by Raman scattering and FTIR spectroscopy. The incorporation of BaTiO3 NPs in the matrix of thermoplastic elastomers revealed the shift dependence of the photoluminescence (PL) band depending on the BaTiO3 NP concentration, which was capable of covering a wide visible spectral range. The dependencies of the dielectric relaxation phenomena with the weight of BaTiO3 NPs in thermoplastic polymers blends were also demonstrated.

scholarly journals The Influence of the Ceramic Nanoparticles on the Thermoplastic Polymers Matrix: Their Structural, Optical, and Conductive Properties

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2773
Author(s):  
Ion Smaranda ◽  
Andreea Nila ◽  
Paul Ganea ◽  
Monica Daescu ◽  
Irina Zgura ◽  
...  
Keyword(s):  
Weight Ratio ◽  
Relaxation Processes ◽  
X Ray Diffraction ◽  
Thermoplastic Polymers ◽  
Dipolar Relaxation ◽  
Ceramic Nanoparticles ◽  
Preferential Adsorption ◽  
Conductive Properties ◽  
Ir Bands ◽  
Pl Quenching

This paper prepared composites under the free membranes form that are based on thermoplastic polymers of the type of polyurethane (TPU) and polyolefin (TPO), which are blended in the weight ratio of 2:1, and ceramic nanoparticles (CNs) such as BaSrTiO3 and SrTiO3. The structural, optical, and conductive properties of these new composite materials are reported. The X-ray diffraction studies highlight a cubic crystalline structure of these CNs. The main variations in the vibrational properties of the TPU:TPO blend induced by CNs consist of the following: (i) the increase in the intensity of the Raman line of 1616 cm−1; (ii) the down-shift of the IR band from 800 to 791 cm−1; (iii) the change of the ratio between the absorbance of IR bands localized in the spectral range 950–1200 cm−1; and (iv) the decrease in the absorbance of the IR band from 1221 cm−1. All these variations were correlated with a preferential adsorption of thermoplastic polymers on the CNs surface. A photoluminescence (PL) quenching process of thermoplastic polymers is demonstrated to occur in the presence of CNs. The anisotropic PL measurements have highlighted a change in the angle of the binding of the TPU:TPO blend, which varies from 23.7° to ≈49.3° and ≈53.4°, when the concentration of BaSrTiO3 and SrTiO3 CNs, respectively, is changed from 0 to 25 wt. %. Using dielectric spectroscopy, two mechanisms are invoked to take place in the case of the composites based on TPU:TPO blends and CNs, i.e., one regarding the type of the electrical conduction and another specifying the dielectric–dipolar relaxation processes.

Effect of Milling Speed on the Synthesis of In-Situ Cu-25 Vol. % WC Nanocomposite by Mechanical Alloying

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Nurulhuda Bashirom ◽  
Nurzatil Ismah Mohd Arif
Keyword(s):  
Stainless Steel ◽  
Mechanical Alloying ◽  
Weight Ratio ◽  
High Energy ◽  
Milling Process ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
The Matrix ◽  
Steel Balls

This paper presents a study on the effect of milling speed on the synthesis of Cu-WC nanocomposites by mechanical alloying (MA). The Cu-WC nanocomposite with nominal composition of 25 vol.% of WC was produced in-situ via MA from elemental powders of copper (Cu), tungsten (W), and graphite (C). These powders were milled in the high-energy “Pulverisette 6” planetary ball mill according to composition Cu-34.90 wt% W-2.28 wt% C. The powders were milled in different milling speed; 400 rpm, 500 rpm, and 600 rpm. The milling process was conducted under argon atmosphere by using a stainless steel vial and 10 mm diameter of stainless steel balls, with ball-to-powder weight ratio (BPR) 10:1. The as-milled powders were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD result showed the formation of W2C phase after milling for 400 rpm and as the speed increased, the peak was broadened. No WC phase was detected after milling. Increasing the milling speed resulted in smaller crystallite size of Cu and proven to be in nanosized. Based on SEM result, higher milling speed leads to the refinement of hard W particles in the Cu matrix. Up to the 600 rpm, the unreacted W particles still existed in the matrix showing 20 hours milling time was not sufficient to completely dissolve the W.

Effect of TiC Particles Volume Fraction on the Mutual Diffusion of Al and Mg during Fabrication of Al-4.5wt%Mg/TiC via Mechanical Alloying Process

2012 ◽  
Vol 326-328 ◽  
pp. 141-146 ◽  
Author(s):  
O. Ozhdelnia ◽  
Ali Shokuhfar
Keyword(s):  
Mechanical Alloying ◽  
Volume Fraction ◽  
Weight Ratio ◽  
Lattice Parameter ◽  
Mutual Diffusion ◽  
X Ray Diffraction ◽  
The Matrix ◽  
Elemental Diffusion ◽  
Diffraction Patterns ◽  
Composite Samples

In this work the effects of volume fraction at different milling times and impact forces, defined as the ball-to-powder weight ratio (BPR), on the elemental diffusion during mechanical alloying process of Al-4.5wt%Mg/TiC composite were evaluated and compared with the TiC free samples (Al-4.5wt%Mg alloy). X-ray diffraction patterns of the monolithic and composite samples imply the fact that a higher level of mutual diffusion of constituents, Al and Mg, happened in the matrix in the presence of TiC particles. This effect of the reinforcing particles can be attributed to the increased densities of dislocation and vacancy caused by the presence of TiC particles within the matrix-giving rise to increasing the micro-strain, lattice parameter and decreasing the crystallite size. Scanning electron microscopy (SEM) was used not only to study the morphology of the powders but also to show the fact that the TiC powders were distributed during MA process. The TEM and HRTEM results showed that powder produced in this work has a nanosize.

Preparation Process Optimization and Characterization of an Ultra-Hard Al-Mg-B Material

2009 ◽  
Vol 79-82 ◽  
pp. 279-282
Author(s):  
Gang Feng ◽  
Lin Zhang ◽  
Guang Hui Min
Keyword(s):  
Bending Strength ◽  
Raw Materials ◽  
Weight Ratio ◽  
Sintered Body ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sinter Method ◽  
The Matrix ◽  
Metal Borides

The Al-Mg-B polycrystalline bodies were prepared using vacuum hot-pressing sinter method by pure Al, Mg and B powders. Process parameters and constitution variation were investigated to obtain compact Al-Mg-B sintered body with high mechanical properties. Al-13%Mg-72.7%B(weight ratio) sintered body prepared under 1600°C, 30MPa for 1 hour in vacuum was proved to be optimum, which bending strength was 156MPa and Vickers hardness was 2220. X-ray diffraction (XRD), Micron Probe Micro-analyzer (EPMA) were employed to analyse the ultimate phases. The results showed that the matrix phases were metal borides including AlB12, MgB6 and AlMgB14, while Al2O3 and MgAl2O4 phases existed which connected or filled in the matrix grains to promote the compactness degree, where oxygen introduced from impurities in raw materials. A portion of Mg in AlMgB14 combined with oxygen during heating to 1600°C which helped to form MgAl2O4 and AlB12 in the end.

scholarly journals Facile Preparation of Biocomposite from Prawn Shell Derived Chitosan and Kaolinite-Rich Locally Available Clay

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Shanta Biswas ◽  
Taslim U. Rashid ◽  
Abul K. Mallik ◽  
Md. Minhajul Islam ◽  
M. Nuruzzaman Khan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Ratio ◽  
Alkaline Media ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
The Matrix ◽  
Acidic And Alkaline Media ◽  
Thermal Stability Of

A novel composite material was prepared from prawn shell derived chitosan (CHT) and locally available kaolinite-rich modified Bijoypur clay (MC) using a facile technique in which dilute acetic acid was used as a solvent for dissolving chitosan and composite fabrication whereas distilled water was used for preparing the clay dispersion. Bijoypur clay mainly consists of kaolinite clay mineral and it was modified with the dodecyl amine to make it organophilic. Morphology and properties of the composites (different weight ratio of MC and CHT) have been studied and compared with those of pure CHT and MC. Purification and modification of Bijoypur clay were investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier transformed infrared spectroscopy (FTIR) analyses. The fabrication of CHT-MC composites was confirmed by FTIR analysis. Thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC) were used to investigate the thermal stability of the composites. It was observed that dispersed clay improves the thermal stability and enhances the hardness of the matrix systematically with the increase of clay loading. In this study, a better insolubility in both acidic and alkaline media of the composites is also observed compared to pure chitosan.

scholarly journals Comparison of the Dielectric Properties of Ecoflex® with L,D-Poly(Lactic Acid) or Polycaprolactone in the Presence of SWCN or 5CB

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1719
Author(s):  
Patryk Fryń ◽  
Sebastian Lalik ◽  
Natalia Górska ◽  
Agnieszka Iwan ◽  
Monika Marzec
Keyword(s):  
Oleic Acid ◽  
Dielectric Properties ◽  
Polymer Matrix ◽  
Liquid Crystalline ◽  
Weight Ratio ◽  
Poly Lactic Acid ◽  
Relaxation Processes ◽  
The Matrix ◽  
Walled Carbon Nanotubes ◽  
Hybrid Layers

The main goal of this paper was to study the dielectric properties of hybrid binary and ternary composites based on biodegradable polymer Ecoflex®, single walled carbon nanotubes (SWCN), and liquid crystalline 4′-pentyl-4-biphenylcarbonitrile (5CB) compound. The obtained results were compared with other created analogically to Ecoflex®, hybrid layers based on biodegradable polymers such as L,D-polylactide (L,D-PLA) and polycaprolactone (PCL). Frequency domain dielectric spectroscopy (FDDS) results were analyzed taking into consideration the amount of SWCN, frequency, and temperature. For pure Ecoflex®, two relaxation processes (α and β) were identified. It was shown that the SWCN admixture (in the weight ratio 10:0.01) did not change the properties of the Ecoflex® layer, while in the case of PCL and L,D-PLA, the layers became conductive. The dielectric constant increased with an increase in the content of SWCN in the Ecoflex® matrix and the conductive behavior was not visible, even for the greatest concentration (10:0.06 weight ratio). In the case of the Ecoflex® polymer matrix, the conduction relaxation process at a frequency ca. several kilohertz appeared and became stronger with an increase in the SWCN admixture in the matrix. Addition of oleic acid to the polymer matrix had a smaller effect on the increase in the dielectric response than the addition of liquid crystal 5CB. Fourier transform infrared (FTIR) results revealed that the molecular structure and chemical character of the Ecoflex® and PCL matrixes remained unchanged upon the addition of SWCN or 5CB in a weight ratio of 10:0.01 and 10:1, respectively, while molecular interactions appeared between L,D-PLA and 5CB. Moreover, adding oleic acid to pure Ecoflex® as well as the binary and ternary hybrid layers with SWCN and/or 5CB in a weight ratio of Ecoflex®:oleic acid equal to 10:0.3 did not have an influence on the chemical bonding of these materials.

Lead inclusions in aluminium

1989 ◽  
Vol 157 ◽  
Author(s):  
E. Johnson ◽  
L. Gråbaek ◽  
J. Bohr ◽  
A. Johansen ◽  
L. Sarholt-Kristensen ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Room Temperature ◽  
Noble Gas ◽  
Melting Transition ◽  
X Ray Diffraction ◽  
Free Surfaces ◽  
The Matrix ◽  
Mean Size ◽  
The Mean ◽  
Spontaneous Phase

ABSTRACTIon implantation at room temperature of lead into aluminium leads to spontaneous phase separation and formation of lead precipitates growing topotactically with the matrix. Unlike the highly pressurised (∼ 1–5 GPa) solid inclusions formed after noble gas implantations, the pressure in the lead precipitates is found to be less than 0.12 GPa.Recently we have observed the intriguing result that the lead inclusions in aluminium exhibit both superheating and supercooling [1]. In this paper we review and elaborate on these results. Small implantation-induced lead precipitates embedded in an aluminium matrix were studied by X-ray diffraction. The (111) Bragg peak originating from the lead crystals was followed during several temperature cycles, from room temperature to 678 K. The melting temperature for bulk lead is 601 K. In the first heating cycle we found a superheating of the lead precipitates of 67 K before melting occurred. During subsequent cooling a supercooling of 21 K below the solidification point of bulk lead was observed. In the subsequent heating cycles this hysteresis at the melting transition was reproducible. The full width of the hysteresis loop slowly decreased to 62 K, while the mean size of the inclusions gradually increased from 14.5 nm to 27 nm. The phenomena of superheating and supercooling are thus most pronounced for the small crystallites. The persistence of the hysteresis loop over successive heating cycles demonstrate that its cause is intrinsic in nature, and it is believed that the superheating originates from the lack of free surfaces of the lead inclusions.

scholarly journals Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongfang Qian ◽  
Zhen Zhang ◽  
Laijiu Zheng ◽  
Ruoyuan Song ◽  
Yuping Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weight Ratio ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Tissue Engineering Scaffolds ◽  
Elongation At Break ◽  
Nanofibrous Scaffolds ◽  
Two Peaks

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.

Crystallization of Zn-rich and P-rich amorphous Zn3P2 thin films

1988 ◽  
Vol 66 (5) ◽  
pp. 373-375 ◽  
Author(s):  
C. J. Arsenault ◽  
D. E. Brodie
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Activation Energy ◽  
Electrical Properties ◽  
Structural Properties ◽  
Crystallization Process ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Conductivity Activation Energy ◽  
X Ray

Zn-rich and P-rich amorphous Zn3P2 thin films were prepared by co-evaporation of the excess element during the normal Zn3P2 deposition. X-ray diffraction techniques were used to investigate the structural properties and the crystallization process. Agglomeration of the excess element within the as-made amorphous Zn3P2 thin film accounted for the structural properties observed after annealing the sample. Electrical measurements showed that excess Zn reduces the conductivity activation energy and increases the conductivity, while excess P up to 15 at.% does not alter the electrical properties significantly.

Synthesis, Characterization and Properties of PANI/(La-Nd Doped BaFe12O19) Composites

2017 ◽  
Vol 727 ◽  
pp. 327-334
Author(s):  
Yan Wang ◽  
Jun Wang ◽  
Xiao Fei Zhang ◽  
Ya Qing Liu
Keyword(s):  
Sol Gel ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Structure Morphology ◽  
Xrd Patterns ◽  
Hexagonal Platelet ◽  
Peak Value ◽  
Properties Of Composites

La-Nd co-doped barium hexaferrites, Ba0.7(LamNdn)0.3Fe12O19 (D-BaM), were successfully prepared by sol-gel method. PANI / D-BaM composites were synthesized by in-situ polymerization in solution. The structure, morphology and properties of samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), four-probe conductivity tester and vector network analyzer. The XRD patterns showed that the crystal structure of all the samples exist as M-type phases. The SEM images revealed that the particles presented a hexagonal platelet-like morphology. The magnetic properties could be improved by substitutions of La and Nd ions. The saturation magnetization (Ms) and coercive force (Hc) increased with the change of La / Nd ratio to the maximum at La / Nd = 3:1. The doped particles have also been embedded in conductive PANI to prepare electromagnetic materials, and the conductivity kept on the order of 10-2. The microwave absorbing properties of composites at 30 MHz-6 GHz improved obviously, the peak value of reflection loss could reach-7.5 dB.

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