scholarly journals Effect Of Different Molecular Coating on The Heating Properties of Maghemite Nanoparticles

2021 ◽  
Author(s):  
Marco Sanna Angotzi ◽  
Valentina Mameli ◽  
Shankar Khanal ◽  
Miroslav Veverka ◽  
Jana Vejpravova ◽  
...  

In this work, the effect of different molecular coatings on the alternate magnetic field-induced heating properties of 15 nm maghemite nanoparticles (NPs) in water dispersions was studied at different frequencies...

Author(s):  
Maciej Konopacki ◽  
Bartłomiej Grygorcewicz ◽  
Marian Kordas ◽  
Barbara Dołęgowska ◽  
Rafał Rakoczy

2014 ◽  
Vol 6 (7) ◽  
pp. 5244-5254 ◽  
Author(s):  
Yuan Yao ◽  
Ezzeldin Metwalli ◽  
Martin A. Niedermeier ◽  
Matthias Opel ◽  
Chen Lin ◽  
...  

2010 ◽  
Vol 1258 ◽  
Author(s):  
Il Tae Kim ◽  
Grady A Nunnery ◽  
Karl I Jacob ◽  
Justin Schwartz ◽  
Xiaotao Liu ◽  
...  

AbstractWe describe a novel, facile method for the alignment of multi-walled carbon nanotubes (MWNTs) in a magnetic field facilitated by the decoration of the MWNTs with monodisperse γ-Fe2O3 magnetic (maghemite) nanoparticles. The tethering of the nanoparticles was achieved by the attachment of γ-Fe2O3 nanoparticles that were synthesized using a modified sol-gel process, onto the carboxylate-activated MWNTs. Sodium dodecylbenzene sulfonate (NaDDBS) was used to prevent the formation of an iron oxide 3D network. Various characterization methods were employed to confirm the formation of homogeneously-distributed and nearly-monodispersed iron oxide nanoparticles, and show that they were indeed tethered to the walls of the MWNTs. The γ-Fe2O3 nanoparticles imparted magnetic characteristics to the MWNTs, which in turn, were oriented parallel to the direction of an externally-applied magnetic field. This facile alignment of MWNT could promote the enhancement of various properties, e.g. mechanical and electrical properties, of the resulting composites. Moreover, this facile alignment at low magnetic fields, made possible by the magnetization of the carbon nanotubes through the tethering of maghemite nanoparticles, may be applied to a variety of other useful nanofillers, such a glass fibers, clay nanoparticles and cellulose nanowhiskers.


Soft Matter ◽  
2021 ◽  
Author(s):  
Thiago Fiuza ◽  
Mitradeep Sarkar ◽  
Jesse Cornelius Riedl ◽  
Andrejs Cebers ◽  
Fabrice Cousin ◽  
...  

Ferrofluids based on maghemite nanoparticles (NPs), typically 10 nm in diameter, are dispersed in an ionic liquid (1-ethyl 3-methylimidazolium bistriflimide - EMIM-TFSI). The average interparticle interaction is found repulsive by...


SPE Journal ◽  
2020 ◽  
Vol 25 (05) ◽  
pp. 2482-2495
Author(s):  
Jared Theurer ◽  
Oluwatobi Ajagbe ◽  
Jhouly Osorio ◽  
Rida Elgaddafi ◽  
Ramadan Ahmed ◽  
...  

Summary Recent studies have shown encouraging results using amine-coated magnetite (Fe3O4) nanoparticles to remove residual oil from produced water using a magnetic field. However, the manufacturing of magnetite nanoparticles requires an expensive coating operation, which limits the application of this technology in large-scale treatment operations. The goal of this study is to develop a simple, efficient, and economically feasible method for removing oil from produced water using nanoparticles. Iron oxide nanoparticles are biocompatible and even safely used in medical applications. This study focuses on the removal of residual oil from produced water using uncoated, recyclable, and less expensive maghemite (γ-Fe2O3) nanoparticles. These particles have shown the potential for removing oil layers from the surface of water. However, they have not been tested for their capability of removing emulsified and dissolved oil from produced water. In this study, commercial and synthesized maghemite nanoparticles were used. The maghemite nanoparticles were synthesized using the coprecipitation process. Laboratory-synthesized produced water samples with high oil concentration (1,000 ppm) were prepared by mixing medium oil with brine [1,180 ppm sodium chloride (NaCl) solution]. The nanoparticles were dispersed in 3% NaCl brine (w/w) at varying concentrations (0.31 to 5 mg/cm3) to form different nanosuspensions. Subsequently, the nanosuspensions were mixed with synthesized produced water for 10 minutes. When a magnetic field was applied to the mixture, a clear separation of the nanoparticles was observed within seconds. Residual oil in the samples was measured using nondispersive infrared spectroscopy. Oil content analysis confirmed the successful (99.9%) removal of oil from laboratory-synthesized water samples. For the real produced water samples, results showed a reduction of oil content to an undetectable level (i.e., less than 0.1 ppm). The ease of nanoparticle collection and washing after subsequent water treatments further demonstrates the feasibility of magnetic nanoparticle (MNP)-based separations for large-scale use in produced water treatment operations. The unique finding of this study is the elimination of one additional step of synthesizing (amine coating) MNPs. Direct use of uncoated maghemite nanoparticles with high oil removal efficiency can reduce produced water treatment costs and promote this technology as an economically feasible option within the industry.


2016 ◽  
Vol 45 (18) ◽  
pp. 7605-7615 ◽  
Author(s):  
Hajo Meyer ◽  
Markus Brenner ◽  
Simon-P. Höfert ◽  
Tim-O. Knedel ◽  
Peter C. Kunz ◽  
...  

Labile and intensely colored CORMs are stabilized in alginate–dextran composites.


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