scholarly journals Influence of Carboxylic Modification Using Polyacrylic Acid on Characteristics of Fe3O4 Nanoparticles with Cluster Structure

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1795
Author(s):  
Jae Rok Shin ◽  
Gye Seok An ◽  
Sung-Churl Choi
Keyword(s):  
Magnetic Properties ◽  
Surface Modification ◽  
Polyacrylic Acid ◽  
Fe3o4 Nanoparticles ◽  
Structural Changes ◽  
Cluster Structure ◽  
Particle Surface ◽  
High Tech ◽  
Optical Parameters ◽  
Surface Modified

Fe3O4 nanoparticles with cluster structure are superparamagnetic particles with applicability in various high-tech fields. In this study, the influence of surface modification with polyacrylic acid (PAA), a polymeric precursor, on the characteristics of Fe3O4 nanoparticles was investigated. The particles were synthesized by the polyol method and surface modified with various amounts of PAA. The surficial, structural, optical, and magnetic properties of the PAA-modified Fe3O4 nanoparticles were analyzed, confirming that negatively charged carboxyl groups were formed on the particle surface, and the particle dispersibility was enhanced by surface modification. This arises from an increase in the electrostatic repulsive force due to the surface functional groups. Functionalization promoted dissociation of the cluster particles, which became more pronounced as the PAA content increased. The optical parameters changed with the PAA content. Analysis of the magnetic properties showed that the saturation magnetization decreased as the PAA content increased. Overall, PAA modification induces structural changes of the Fe3O4 nanoparticles that enhance the dispersibility and influence the characteristics of the particles.

scholarly journals Magnetic properties and giant magnetoimpedance effect for CoFeMoSiB surface modified amorphous ribbons covered by water based ferrofluid

2018 ◽  
Vol 185 ◽  
pp. 10003
Author(s):  
Zahra Lotfollahi ◽  
Ahmad Amirabadizadeh ◽  
Alexander P. Safronov ◽  
Galina V. Kurlyandskaya
Keyword(s):  
Magnetic Properties ◽  
Surface Modification ◽  
Average Diameter ◽  
Ultrasound Treatment ◽  
Giant Magnetoimpedance ◽  
Giant Magnetoimpedance Effect ◽  
Gmi Effect ◽  
Amorphous Ribbons ◽  
Water Based ◽  
Surface Modified

Giant magnetoimpedance (GMI) effect is a powerful technique for magnetic label detection. Co-based amorphous ribbons are cheap materials showing high GMI effect at low operation frequencies for close to zero magnitostriction compositions. In this work magnetic properties and GMI were studied for CoFeMoSiB amorphous ribbons in as-quenched and surface modified states without and in the presence of water-based ferrofluid with electrostatic stabilization of γ-Fe2O3 nanoparticles. Surface modification by ultrasound treatment resulted in appearance of round defects with average diameter of about 150 micrometers. The GMI difference for as-quenched ribbons in absence and in the presence of ferrofluid was measured for the frequency range of 0.5 to 10 MHz. Although proposed surface modification by the ultrasound treatment did not improve the sensitivity limit for ferrofluid detection, it did not decrease it either. Observed changes of GMI are useful for understanding of functionality of GMI biosensors.

scholarly journals Laser direct structuring and electroless plating applicable super-engineering plastic PPS based thermal conductive composite with particle surface modification

RSC Advances ◽  
2018 ◽  
Vol 8 (18) ◽  
pp. 9933-9940
Author(s):  
Kiho Kim ◽  
Jinseong Lee ◽  
Seokgyu Ryu ◽  
Jooheon Kim
Keyword(s):  
Surface Modification ◽  
Boron Nitride ◽  
Polymer Matrix ◽  
Electroless Plating ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Particle Surface ◽  
Engineering Plastic ◽  
Silane Coupling ◽  
Surface Modified

Boron nitride (BN) and laser activate particles (LAPs) which used for electroless plating were surface-modifiedviabase treatment and by using a silane coupling agent in order to confer functionality and enhance the interfacial affinity of these particles for a polymer matrix.

Surface modification of Fe3O4 nanoparticles and their magnetic properties

2009 ◽  
Vol 16 (2) ◽  
pp. 226-229 ◽  
Author(s):  
Hao Yan ◽  
Jian-cheng Zhang ◽  
Chen-xia You ◽  
Zhen-wei Song ◽  
Ben-wei Yu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Surface Modification ◽  
Fe3o4 Nanoparticles

Human potential in the system of social and economic development: problems and prospects of Vinnytsia region

2020 ◽  
pp. 71-80
Author(s):  
Olesya Tomchuk
Keyword(s):  
Economic Development ◽  
Human Development ◽  
Rural Areas ◽  
Structural Changes ◽  
Agricultural Sector ◽  
Positive Impact ◽  
Well Being ◽  
Human Potential ◽  
High Tech ◽  
Social And Economic Development

The article highlights the problems and prospects of human development, which is the basis for the long-term strategies of social and economic growth of different countries and regions at the present stage. Submitting strategies of this type provides an opportunity to focus on individual empowerment and to build a favorable environment for effective management decisions in the field of forming, maintaining, and restoring human potential. The analysis of the Vinnytsia region human potential dynamics in the regional system of social and economic development factors was carried out. Application of generalized assessment of the regional human development index components allowed the identification of the main trends that characterize the formation of human potential of the territory, including the reproduction of the population, social environment, comfort and quality of life, well-being, decent work, and education. The article emphasizes that despite some positive changes in the social and economic situation of the region and in assessing the parameters of its human development level relative to other regions of Ukraine, Vinnytsia region is now losing its human potential due to negative demographic situation and migration to other regions and countries. The main reason for such dynamics is proven to be related to the outdated structure of the region's economy, the predominance of the agricultural sector, the lack of progressive transformations in the development of high-tech fields of the economy. An important factor is the low level of urbanization of the region, which leads to the spread of less attractive working conditions and less comfortable living conditions. The key factors that cause the growth of urbanization in the region have been identified, including the significant positive impact of the transport and social infrastructure expansion, the lack of which in rural areas leads to a decrease in the level and comfort of life. Without progressive structural changes in the economy and the resettlement system, the loss of human potential will continue.

EXAFS Study of Co/Ag Multilayers

1993 ◽  
Vol 307 ◽  
Author(s):  
C. L. Foiles ◽  
R. Loloee ◽  
T. I. Morrison
Keyword(s):  
Magnetic Properties ◽  
Significant Role ◽  
Giant Magnetoresistance ◽  
Structural Changes ◽  
Multilayer System ◽  
Basic Form ◽  
Exafs Data ◽  
Simple Scaling ◽  
Exafs Study

ABSTRACTCo EXAFS data for these Co/Ag multilayers exhibit no changes in basic form and obey a simple scaling with Co thickness down to 6Å. Over this same thickness range the giant magnetoresistance and the manner in which magnetization approaches saturation change substantially. These results indicate that local structural changes do not play a significant role in altering the magnetic properties of this multilayer system.

scholarly journals Facile Preparation of Efficient WO3Photocatalysts Based on Surface Modification

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Min Liu ◽  
Hongmei Li ◽  
Yangsu Zeng
Keyword(s):  
Photocatalytic Activity ◽  
Surface Modification ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Impregnation Method ◽  
Light Spectra ◽  
Simple Strategy ◽  
Visible Light Active ◽  
Efficient Charge ◽  
Surface Modified

Tungsten trioxide (WO3) was surface modified with Cu(II) nanoclusters and titanium dioxide (TiO2) nanopowders by using a simple impregnation method followed by a physical combining method. The obtained nanocomposites were studied by scanning electron microscope, X-ray photoelectron spectroscopy spectra, UV-visible light spectra, and photoluminescence, respectively. Although the photocatalytic activity of WO3was negligible under visible light irradiation, the visible light photocatalytic activity of WO3was drastically enhanced by surface modification of Cu(II) nanoclusters and TiO2nanopowders. The enhanced photocatalytic activity is due to the efficient charge separation by TiO2and Cu(II) nanoclusters functioning as cocatalysts on the surface. Thus, this simple strategy provides a facile route to prepare efficient visible-light-active photocatalysts for practical application.

Synthesis of magnetic Fe3O4 micro/nanospheres in organic solvent

2018 ◽  
Vol 16 (1_suppl) ◽  
pp. 26-31
Author(s):  
Tan Heng ◽  
Wang Ze ◽  
Tan Wen-sheng ◽  
Li Xiao-ping ◽  
Qiu Jian-guo ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Magnetic Properties ◽  
Surface Modification ◽  
Nanostructured Materials ◽  
Nitrogen Atmosphere ◽  
Phase Method ◽  
Organic Media ◽  
Chemical Structures ◽  
Amine Functionalized ◽  
Magnetic Fe3o4

Introduction: Micro/nanostructured materials have attracted a great deal of attention, and many strategies have been developed to fabricate micro/nanostructured materials. Methods: Amine-functionalized micro/nanostructured Fe3O4 with different sizes was synthesized conveniently in organic media. The chemical structures of as-synthesized products were characterized by FTIR, TEM, SEM, and XRD. Results: The ligand binds to the Fe3O4 core by hydrogen bond between the oxygen atom on the surface of Fe3O4 and the hydrogen atom in molecular ethylenediamine. Their magnetic properties were also investigated. Conclusions: First, there is no need to control the reaction under a nitrogen atmosphere, and just one salt is used as an iron source. The growth and the surface modification of Fe3O4 crystalline nucleation happen at the same time. Second, monodispersed Fe3O4 micro/nanospheres were prepared without additional surfactant or external magnetic fields. Third, this method is preferred compared with the conventional organic phase method, as the reaction condition is milder and less pollutant will be produced.

The Production and Properties of Copper-Iron Particulate Composite Wire

1989 ◽  
Vol 203 (3) ◽  
pp. 175-184
Author(s):  
G I Lawal ◽  
D C Barton ◽  
A N Bramley ◽  
J Nutting
Keyword(s):  
Magnetic Properties ◽  
Structural Changes ◽  
Copper Wire ◽  
Particulate Composite ◽  
Iron Particle ◽  
Composite Wire ◽  
Particulate Form ◽  
Increasing Process ◽  
The Wire ◽  
Magnetic Hardness

A novel means of producing copper-based powder metallurgy wire containing sufficient iron in particulate form to impart useful magnetic properties has been investigated. The method, which involves encapsulating a powder mixture within a copper tube prior to rolling and die-drawing operations, has been successfully used to produce composite wire of diameter range 1.8-0.4 mm. Particular attention has been paid to the effect of composition, processing strain, heat treatment and iron particle size on the electrical, mechanical and magnetic properties of the wire. Microscopy studies have also been carried out to determine structural changes in the material during processing. It was found that the good conductivity and ductility of solid copper wire was not greatly reduced provided (a) the iron content of the composite wire was kept fairly low (<6 per cent) and (b) the annealing temperature was not sufficiently high for significant alloying to take place (650°C maximum). Saturation magnetization values increased with increasing process strain, as did the magnetic hardness. The latter, however, could be minimized by fully annealing the iron after processing the wire. The magnetic properties were undoubtedly influenced by the size and shape of the iron particles, smaller particles being more easily elongated and tending to give greater magnetic hardness.

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