Magnetic behaviour of nanocrystalline Cu–Fe–Co/Al2O3 composite powders obtained by mechanical alloying

ACS Appl. Mater. Interfaces

2020

Self Cite

The pollution of oceans and seas by oils and microplastics is a significant global issue affecting the economy and environment. Therefore, it is necessary to search for different technologies that can remove these pollutants in a sustainable way. Herein, superhydrophobic powdered iron was used to efficiently separate stabilized oil-in-water emulsions and, remarkably, capture microplastic fibers. High-energy ball milling of iron particles was applied to decrease particle size, increase the specific surface area, and produce a nanostructured material. This was combined with the liquid phase deposition of lauric acid to modify the surface free energy. The nanostructured powder showed superhydrophobicity (WCA = 154°) and superoleophilicity (OCA = 0°), which were fundamental in separating stabilized oil-in-water emulsions of hexane with an efficiency close to 100%. Because of the superhydrophobic/superoleophilic properties of the powdered iron and its intrinsic properties of being able to freely move and adapt to the different morphologies of microplastics under continuous stirring, this material can capture microplastic fibers. Thus, we present a novel dual application of a superhydrophobic material, which includes the capture of microplastics. This has not been reported previously and provides a new scope for future environmental sustainability.

“…All the diffraction peaks broadened with longer HEBM times, indicating a decrease in the crystalline size leading to the formation of a nanostructured material, as observed previously. , …”

Section: Structural Characterizationsupporting

confidence: 84%

Section: Structural Characterizationmentioning

confidence: 99%

Superhydrophobic and Sustainable Nanostructured Powdered Iron for the Efficient Separation of Oil-in-Water Emulsions and the Capture of Microplastics

Rius-Ayra

Bouhnouf-Riahi

ACS Appl. Mater. Interfaces

2020

Self Cite

“…It was observed that Co was the first element entering into the structure of Cu, its peaks decreased in intensity as observed in previous works after less than 3 hours of milling. It was also confirmed previously that by few hours of milling bcc iron endeavors a crystallographic phase transformation to fcc due to the intense accumulative strain of the process [6]. Thus, a solid solution -Cu(Co,Fe) could be recognized.…”

Section: Fig 2 Xrd Patters For Cu-fe-co Powder After Different Millin...supporting

confidence: 74%

Synthesis and Characterization of Nanostructured Mechanical Cu-Fe-Co Alloy

Biserova-Tahchieva

López-Jiménez

2018

MSF

Nanocrystalline structure of CuFeCo (50:25:25 wt%) alloy has been obtained by high energy mechanical milling from elemental metal powder mixture during large hours of work. Phase transformations and diffusion in the system subjected to heat treatment are discussed. Thermal stability at high temperatures is analysed and considered of importance for several applications. The nanostructure was studied by employing X-Ray diffraction and electron microscopy. It has been determined the reduction in crystallite size and the induced microstrain by the milling time. The solid solution achievement through the increment of defect density was confirmed by Mössbauer analysis. Magnetic behaviour was analysed through magnetization technique entailing their soft ferromagnetic behaviour related to the microstructural changes.

“…Four sets of samples with the same compositional ratio were processed by high-energy ball milling in a Fritsch planetary monomill Pulverisette P6 with steel balls and vials. This equipment works at the specific impact energy of the balls of 6-7 kJ/s -1 kg -1 [9]. The experimental conditions of the mechanical alloying process (MA) were the following: disc rotation speed of 300 rpm (Ω) and vial rotation speed of 546 rpm (ω) and the ball-to-powder weight ratio was 16:1 in all experiments.…”

Section: Methodsmentioning

confidence: 99%

“…All of these factors determine the hysteresis loop and consequently affect magnetic parameters such as saturation magnetization, Ms, coercivity, Hc, and remanence, Mr. Magnetic force microscopy (MFM) has become one of the most widespread tools for studying the magnetic domains of ferromagnetic samples [9]. Some authors [10][11][12] report MFM investigations of ribbons of melt-spun nanomaterials and electrodeposited layers and films, but the use of MFM in the study of mechanical alloyed nanopowders has not been widely reported yet [9].…”

Section: Introductionmentioning

confidence: 99%

Influence of Oxide Additions in Cu-Co-Fe Composite Powders Obtained by Mechanical Alloying

Artieda-Guzmán

Vique

et al. 2014

MSF

Nanocrystalline composite powders were prepared by mechanical alloying of pure Cu, Fe and Co as metallic major part and Al2O3 or Fe2O3 or SiO2 as ceramic reinforcement in a high-energy ball mill. Alloys of the copper-iron-cobalt system are promising for the development of new materials and applications. Cu-Fe-Co is used in different applications depending on the properties required. These can be related for example to toughness when used as rock cutting tool, to magnetic and electric properties for microelectronics or to chemical behaviour when used as catalysts in bioalcohol production industry. The objective of the present study is to contribute to understanding how and to which amount the ceramic reinforcement affects the properties for which this Cu-Fe-Co system is used as well as to envisage other less frequently uses for the composite powders. Structural and magnetic transformations occurring in the material during milling were studied with the use of X-ray diffraction, scanning quantum induction device (SQUID) and magnetic force microscopy (MFM). In mechanical alloying the transformations depend upon milling time. The results showed that milling the elemental powders of Cu-Fe-Co in the mass proportion of 50:25:25 respectively for times up to 10h leads to the progressive dissolution of Fe and Co atoms into FCC Cu and the final product of the MA process was the nanocrystalline Cu containing Fe and Co with a mean crystallite size (from coherent crystal size determination by diffraction) of 20 nm aprox. When ceramic particles are milled together with the metals (at proportions of the oxides between 1-10%) this mechanism is retarded. On the other hand, the lowest mean crystallite size is reached without ceramic particles in the milling process. However the composite powder produced in all the cases stabilized similar lowest crystallite size between 45-50 nm. Mechanically alloyed metallic-ceramic composite powder showed lower saturation magnetization than the metallic system but enhanced coercive field (significantly for hematite reinforcement). All the studied systems are intermediate ferromagnetics (Hc≈104 A/m). Milling time significantly affects the structure, composition and properties for both metallic and composite systems.