scholarly journals Polysubstituted High-Entropy [LaNd](Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 Perovskites: Correlation of the Electrical and Magnetic Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1014
Author(s):  
Vladimir E. Zhivulin ◽  
Evgeniy A. Trofimov ◽  
Svetlana A. Gudkova ◽  
Igor Yu. Pashkeev ◽  
Alexander Yu. Punda ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Chemical Composition ◽  
Average Particle Size ◽  
Maximum Size ◽  
Average Particle ◽  
Ferromagnetic Cluster ◽  
High Entropy ◽  
Wide Range ◽  
Field Cooling

La-, Nd- and La/Nd-based polysubstituted high-entropy oxides (HEOs) were produced by solid-state reactions. Composition of the B-site was fixed for all samples (Cr0.2Mn0.2Fe0.2Co0.2Ni0.2) with varying of A-site cation (La, Nd and La0.5Nd0.5). Nominal chemical composition of the HEOs correlates well with initial calculated stoichiometry. All produced samples are single phase with perovskite-like structure. Average particle size is critically dependent on chemical composition. Minimal average particle size (~400 nm) was observed for the La-based sample and maximal average particle size (5.8 μm) was observed for the Nd-based sample. The values of the configurational entropy of mixing for each sample were calculated. Electrical properties were investigated in the wide range of temperatures (150–450 K) and frequencies (10−1–107 Hz). Results are discussed in terms of the variable range hopping and the small polaron hopping mechanisms. Magnetic properties were analyzed from the temperature and field dependences of the specific magnetization. The frustrated state of the spin subsystem was observed, and it can be a result of the increasing entropy state. From the Zero-Field-Cooling and Field-Cooling regimes (ZFC-FC) curves, we determine the <S> average and Smax maximum size of a ferromagnetic nanocluster in a paramagnetic matrix. The <S> average size of a ferromagnetic cluster is ~100 nm (La-CMFCNO) and ~60 nm (LN-CMFCNO). The Smax maximum size is ~210 nm (La-CMFCNO) and ~205 nm (LN-CMFCNO). For Nd-CMFCNO, spin glass state (ferromagnetic cluster lower than 30 nm) was observed due to f-d exchange at low temperatures.

MICROSTRUCTURE AND MAGNETIC PROPERTIES OF Sm2Fe17NNx−ALLOY- POWDERS AND OF BONDED ANISOTROPIC MAGNETS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 716-720
Author(s):  
B. WALL ◽  
M. KATTER ◽  
W. RODEWALD ◽  
M. VELICESCU
Keyword(s):  
Solid Solution ◽  
Particle Size ◽  
Magnetic Properties ◽  
Average Particle Size ◽  
Average Particle ◽  
Interstitial Solid Solution ◽  
Demagnetization Curve ◽  
Microstructure And Magnetic Properties

In cast Sm2Fe17 ingots minor fractions of SmFe2 and SmFe3 may occur. Nitrogenation of such alloy-powders inidicates that only Sm2Fe17 forms an interstitial solid solution whereas SmFe2 and SmFe3 decompose directly into SmN and α-Fe. From Sm2Fe17Nx alloy powders with an average particle size of about 3 μm anisotropic magnets were prepared by adding 15 wt% Zn-powder. Annealing at 390 ºC results in intrinsic coercivities > 15 kOe promoted by the formation of an unknown binary Fe8Zn92-compound. Whereas annealing at temperatures > 420 ºC leads to the formation of binary Fe3Zn7 and ternary Sm2FeZn2. By the formation of Sm2FeZn2 from Sm2Fe17Nx+Zn some α-Fe occurs inducing a step in the demagnetization curve J(H).

scholarly journals Preparation and Investigation of Intelligent Polymeric Nanocapsule for Enhanced Oil Recovery

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1093 ◽  
Author(s):  
Fang Shi ◽  
Jingchun Wu ◽  
Bo Zhao
Keyword(s):  
Particle Size ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Colloidal Particles ◽  
Critical Concentration ◽  
Average Particle Size ◽  
Average Particle ◽  
Assembly Method ◽  
Recovery Capacity ◽  
Wide Range

Micro-/nanomotors colloidal particles have attracted increasing interest as composite surfactants, owing to the combined advantages of both Janus solid surfactants and micro-/nanomotors. Here we put micro-/nanomotors colloidal particles into hollow polymeric micro-encapsulates. An intelligent polymeric nanocapsule was prepared for enhanced oil recovery by the self-assembly method. The particle size range of the polymeric capsule can be controlled between 20 to 1000 nm by adjusting the cross-linking thickness of the capsule’s outer membrane. The average particle size of polymeric capsules prepared in the study was 300 nm. The structure and properties of the Intelligent polymeric nanocapsule was characterized by a wide range of technics such as Fourier transform infrared spectroscopy, scanning electron microscopy by laser diffraction, fluorescence microscopy, pendant drop tensiometer, laser particle size instrument, and interface tension analyzer. It was found that the intelligent polymeric nanocapsule exhibited significant interfacial activity at the oil-water interface. When the Janus particles’ concentration reached saturation concentration, the adsorption of the amphiphilic nanoparticles at the interface was saturated, and the equilibrium surface tension dropped to around 31 mN/m. When the particles’ concentration reached a critical concentration of aggregation, the Gibbs stability criterion was fulfilled. The intelligent polymeric nanocapsule system has a better plugging and enhanced oil recovery capacity. The results obtained provide fundamental insights into the understanding of the assembly behavior and emulsifying properties of the intelligent polymeric nanocapsule, and further demonstrate the future potential of the intelligent polymeric nanocapsule used as colloid surfactants for enhanced oil recovery applications.

Abstract 399: High Throughput Comprehensive Volumetric Approach for Determination of Particle Number and Composition of Lipoproteins in Normolipidemic and Dyslipidemic Populations

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Zsuzsanna Kuklenyik ◽  
John R Barr ◽  
James L Pirkle ◽  
Keyword(s):  
Particle Size ◽  
High Throughput ◽  
Size Range ◽  
Average Particle Size ◽  
Protein Composition ◽  
Average Particle ◽  
Surface Lipid ◽  
Molar Ratios ◽  
Ldl Particles ◽  
Wide Range

Lipoproteins (Lps) are large molecular assembles formed by lipid and apolipoprotein constituents. The physical metric of Lps as metabolically functional entities is particle concentration in serum or plasma (Lp-P). However, the metabolic functions of Lp particles is determined by their lipid/protein composition and structure. To be able to determine both Lp composition and Lp-P, a volumetric approach is required, as demonstrated by Segrest et al and other groups. In this work the volumetric approach was implemented but with applicability to population studies. The workflow included size based separation of Lps by asymmetric flow field-flow fractionation while collecting fractions with 1-1.5 nm increments in the range of 7-15 nm (HDL), 20-30 nm (LDL) and >30 nm Lps (40 fractions in total from 0.1 mL serum aliquots). The average particle size in each fraction was measured by dynamic light scattering. Three high throughput, parallel LC-MS/MS based methods were developed to quantify main non-polar lipids (FC, CE and TG), phospholipids (PC, SM, PE, PI and LPC), and apolipoproteins (apos A-I, A-II, A-IV, B, C-I, C-II, C-III and E). Quantification of particle size and all major Lp components was achieved with 4-15% CVs. Overall accuracy of the methods was demonstrated by ApoB-100/LDL-P molar ratios of 0.7-1.3 (vs. 1 expected) in the 22-26 nm maximum LDL size range. In the 7.5-13 nm size range, ApoA-I/HDL-P was 0.7-3.5 and ApoA-II/HDL-P of 0.5-2.5. Using the calculated Lp-P values, average individual analyte/Lp-P molar ratios were calculated in each fraction. The workflow was applied to 120 patient samples with wide range of Total-C and Total-TG levels. Multivariate response surface modeling was used to show significant correlations among individual lipid/Lp-P and apolipoprotein/Lp-P molar ratios. For example, with correction for particle size, the correlations of apoC-III/Lp-P and FC/Lp-P with SM/Lp-P, PC/Lp-P, TG/Lp-P and CE/Lp-P were determined, showing the effect of surface lipid and core lipid composition on apoC-III and FC binding to HDL and LDL particles, while also revealing significant cross effects among Lp components. By using <0.1 mL serum or plasma, the workflow is applicable to archived samples collected in large cohort studies.

Structure and properties of electroerosive materials from lead bronze waste BrS30, obtained in oxygen- and carbon-containing media

2021 ◽  
pp. 309-312
Author(s):  
E.V. Ageev ◽  
A.S. Pereverzev
Keyword(s):  
Particle Size ◽  
Chemical Composition ◽  
Average Particle Size ◽  
Experimental Studies ◽  
Average Particle ◽  
Distilled Water ◽  
Structure And Properties ◽  
Technological Parameters ◽  
Elliptical Shape

The results of experimental studies of the structure and properties of electroerosive materials from lead bronze waste BrS30 obtained in oxygen- and carbon-containing media are presented. The influence of the chemical composition of liquids and technological parameters of dispersion on the properties of the resulting electroerosive materials is shown. In particular, a part of oxygen is present on the surface of particles obtained in distilled water, and part of carbon is present in lighting kerosene. The average particle size obtained in lighting kerosene is 1.2 times higher than the average particle size obtained in distilled water. The particles of the BrS30 alloy dispersed by electroerosion have a regular spherical, elliptical shape and agglomerates.

Zn-doped SnO2 nanoparticles: Structural, optical, dielectric and magnetic properties

2017 ◽  
Vol 31 (30) ◽  
pp. 1750234 ◽  
Author(s):  
Zulfiqar ◽  
Yuliang Yuan ◽  
Zainab Iqbal ◽  
Jianguo Lu
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Defect Density ◽  
Sno2 Nanoparticles ◽  
Average Particle Size ◽  
Dielectric Materials ◽  
Precipitation Method ◽  
Average Particle ◽  
Zn Content ◽  
Optical Dielectric

Zn-doped SnO2 nanoparticles have been synthesized by the chemical precipitation method with the Zn contents ([Formula: see text]) of 1, 2 and 4 wt.%. The nanoparticles are crystalline in all cases, with the average particle size decreasing from 13.4 nm to 7.71 nm as the Zn concentration increases. The visible photoluminescence emission is observed in Zn-doped SnO2 nanoparticles, with larger emission intensity at elevated Zn content. The dielectric constant has a strong doping dependence, which is evidently enhanced with increasing Zn content. Magnetization measurements reveal the enhancement in saturation magnetization and remanence magnetization, while the reduction in coercive field is observed with increasing amount of Zn dopant. The variation of optical, dielectric and magnetic properties is due to the incorporation of Zn in SnO2 with smaller particle size and higher defect density. The present study clearly reveals the doping-induced ferromagnetism in Zn-doped SnO2 nanoparticles, having applications in ultrahigh dielectric materials, high frequency devices and spintronics.

scholarly journals Silver and Copper nano-colloid generation via Pulsed Laser Ablation in Liquid: Recirculation nanoparticle production mode

2021 ◽  
Author(s):  
Sithara Sreenilayam Pavithran ◽  
Ronan McCann ◽  
Éanna McCarthy ◽  
Brian Freeland ◽  
Karsten Fleischer ◽  
...  
Keyword(s):  
Particle Size ◽  
Laser Ablation ◽  
Average Particle Size ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Average Particle ◽  
Laser Ablation In Liquid ◽  
Wide Range ◽  
Ligand Free ◽  
Unique Chemical

Metal nanoparticles have unique chemical, physical, electrical, and optical properties that make them attractive for a wide range of applications in sensing, anti-fouling surfaces, medicine, and conductive inks. Pulsed Laser Ablation in Liquid (PLAL) is a green method of nanoparticle colloid production, capable of producing ligand-free nanoparticles in solution without the need for hazardous, environmentally unfriendly chemicals. Control of the process parameters can give control over the resulting colloid properties such as particle size distribution. In this work, silver (Ag) nanoparticles (NPs) with average particle size from 2.04 to 19.3 nm and copper (Cu) NPs with average particle size from 40 to 85.9 nm were produced by PLAL) technique.

scholarly journals Chemical Composition and Particle Size of Grape Seed Flour and Their Effects on the Characteristics of Cookies

2019 ◽  
Vol 8 (4) ◽  
pp. 111 ◽  
Author(s):  
Razakou Maman ◽  
Jianmei Yu
Keyword(s):  
Particle Size ◽  
Chemical Composition ◽  
Dietary Fiber ◽  
Average Particle Size ◽  
Grape Seed ◽  
Consumer Acceptability ◽  
Average Particle ◽  
Dependent Manner ◽  
Seed Flour ◽  
Cookie Quality

This study investigated the effect of particle size and chemical composition of grape seed flour (GSF) on the physical, chemical and sensory quality of cookies. Results indicate that the chemical composition of GSF varied significantly with particle sizes and smaller particle fraction had higher ash, fat, protein and extractible polyphenol contents but lower dietary fiber. Inclusion of 2.5-10% GSF in the cookie formula enhanced darkening, increased thickness and hardness, increased polyphenol and dietary fiber contents in dose-dependent manner, but reduced diameter and consumer acceptability of cookies to various degrees. The impacts of GSF on the cookie quality and sensory properties were strongly associated with the inclusion level and particle size of GSF. Higher GSF (5%) inclusion and smaller GSF particle size (104 &micro;m) resulted in lower consumer acceptability. To minimize the undesirable effect of GSF on cookie quality, up to 5% of GSF with average particle size 209 &micro;m is recommended.

Synthesis of Crosslinkable Core-Shell Emulsion and Rheology of the Core-Shell/Amine Crosslinking Process

2009 ◽  
Vol 79-82 ◽  
pp. 2203-2206
Author(s):  
Jia Lu ◽  
Allan J. Easteal ◽  
Debes Bhattacharyya ◽  
Clive J. Bolt ◽  
Neil R. Edmonds
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Complex Viscosity ◽  
Shell Morphology ◽  
Core Shell ◽  
Average Particle ◽  
Crosslinking Reaction ◽  
Shear Moduli ◽  
The Core ◽  
Wide Range

Starve feed and semi-continuous seed emulsion polymerization were used to control the morphology of core shell latex particles with a vinyl acetate (VAc)/vinyl ester of versatic acid 10(VeoVa10) copolymer core surrounded by a poly(glycidyl methacrylate) (PGMA) shell. Pure core and core-shell structures were confirmed by TEM. The results suggest that core-shell morphology of the two stage emulsion was favoured by higher concentration of emulsifier in the seed latex: the particle size distribution of core-shell latex was broader than that of the core latex, and the average particle size of core-shell latex was larger than that of the core latex. The core-shell structure was not produced using seed emulsion with emulsifier concentration at or below the critical micelle concentration. The core shell emulsion containing epoxy functional group with added ethylene diamine showed an abrupt increase in dynamic shear moduli, G' and G'' and complex viscosity η* (several orders of magnitude) at about 35oC, during temperature ramps, over a wide range of angular frequencies. The time ramps showed that the crosslinking reaction did not occur at 15oC for the core-shell emulsion/amine system. The time for gel formation decreased with increase in temperature.

scholarly journals Effect of the Sintering Temperature on the Compressive Strengths of Reticulated Porous Zirconia

2021 ◽  
Vol 11 (12) ◽  
pp. 5672
Author(s):  
Chae-Young Lee ◽  
Sujin Lee ◽  
Jang-Hoon Ha ◽  
Jongman Lee ◽  
In-Hyuck Song ◽  
...  
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Sintering Temperature ◽  
Porous Ceramic ◽  
Average Particle Size ◽  
Porous Ceramics ◽  
Average Particle ◽  
High Porosity ◽  
Wide Range ◽  
Porous Zirconia

Porous ceramics have separation/collection (open pore) and heat-shielding/sound-absorbing (closed pore) characteristics not found in conventional dense ceramics, increasing their industrial importance along with dense ceramics. Reticulated porous ceramics, a type of porous ceramic material, are characterized by a three-dimensional network structure having high porosity and permeability. Although there have been numerous studies of porous zirconia, which is already widely used, there are insufficient reports on reticulated porous zirconia, and it is still challenging to improve the compressive strength of reticulated porous ceramics thus far, especially considering that too few studies have been published on this topic. Therefore, we prepared reticulated porous zirconia specimens using the replica template method. In this study, the compressive strength outcomes of reticulated porous zirconia were analyzed by controlling the PPI value (25, 45, 60, and 80 PPI) of the sacrificial polymer template, the average zirconia particle size (as-received, coarse, intermediate, and fine), and the sintering temperature (1400, 1500, and 1600 °C). Consequently, we confirm that it is possible to prepare reticulated porous zirconia with a wide range of strengths (0.16~1.26 MPa) as needed with an average particle size and while properly controlling the sintering temperature.

Synthesis and Magnetic Properties of Nanosized Cobalt Substituted Nickel Ferrites (Ni1-xCoxFe2O4) Using Egg White (Ovalbumin) by Thermal Evaporation

2009 ◽  
Vol 4 ◽  
pp. 107-116 ◽  
Author(s):  
S. Marutha Senthil ◽  
R. Jayaprakash ◽  
V.N. Singh ◽  
B.R. Mehta ◽  
G. Govindaraj
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Frequency Band ◽  
Thermal Evaporation ◽  
Average Particle Size ◽  
Low Frequency ◽  
Egg White ◽  
Synthesis Process ◽  
Nanocrystalline Phase ◽  
Average Particle

An attempt has been made to synthesize Ni1-xCoxFe2O4 by a simple technique of thermal evaporation with the help of egg white. The use of egg white (ovalbumin) in the synthesis process mainly helps to shape the particle during the reaction. The X-ray diffraction patterns reveal that the synthesized Ni1-XCoxFe2O4 ferrites are in nanocrystalline phase. The transmission electron microscopy observation confirmed that the average particle size of Ni1-xCoxFe2O4 has been varied from 7 nm to 30 nm. EDX spectrum gives account of the percentage composition of the products such as nickel, cobalt, Fe and O. Vibrating Samples Magnetometer (VSM) have been sued to study the saturation magnetization for variation of Ni substitution over CoFe2O4 and the influence of particle size in magnetic properties. Its analysis is based on the aspect of variation in coercivity with temperature. The FTIR spectra of the sample in the range 400 – 4000 cm-1 reveals the common feature of ferrites like high frequency band to the tetrahedral and low frequency band to the octahedral stretching vibrations.

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