High‐gradient magnetic separation of coated magnetic nanoparticles

Moeser, Geoffrey D.; Roach, Kaitlin A.; Green, William; Hatton, T. Alan; Laibinis, Paul E.

doi:10.1002/aic.10270

Cited by 234 publications

(197 citation statements)

References 22 publications

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“…Simulation of magnetic separation units has a long history 20,33,[35][36][37][38][39][40] . A great deal of modeling work has been carried out in the eighties and in the nineties, with the objective to quantify the performances of high gradient magnetic separation (HGMS) units, as they are commonly referred to.…”

Section: Simulationmentioning

confidence: 99%

Magnetic microreactors for efficient and reliable magnetic nanoparticle surface functionalization

et al. 2014

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Microreactors have attracted wide attention in the nano-and biotechnology field because they offer many advantages over standard liquid phase reactions. We report the development of a magnetic microreactor for reliable, fast and efficient surface functionalization of superparamagnetic iron oxide nanoparticles (SPIONs). A comprehensive study is described of the development process in terms of setup, loading capacity and efficiency. We have performed experimental and computational studies in order to evaluate the trapping efficiencies, maximum loading capacity and magnetic alignment of the nanoparticles. The results show that capacity and trapping efficiencies are directly related to the flow rate, elution time and reactor type. Based on our results and the developed magnetic microreactor, we describe a model multistep surface derivatization procedure of SPIONs.

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Section: Simulationmentioning

confidence: 99%

Magnetic microreactors for efficient and reliable magnetic nanoparticle surface functionalization

et al. 2014

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“…Once sorption occurs, the magnetite particles can be removed by high field gradient methods. This is a promising technology for water purification and other contaminant remediation (Moeser et al, 2004). Magnetite nanoparticles are also utilized in ferrofluidic liquids that have applications in many types of bearings and engineering applications.…”

Section: Nanoparticle Studies Of Other Feox Materialsmentioning

confidence: 99%

Nanoparticulate Iron Oxide Minerals in Soils and Sediments: Unique Properties and Contaminant Scavenging Mechanisms

2005

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Nanoparticulate goethite, akaganeite, hematite, ferrihydrite and schwertmannite are important constituents of soils, sediments and mine drainage outflows. These minerals have high sorption capacities for metal and anionic contaminants such as arsenic, chromium, lead, mercury and selenium. Contaminant sequestration is accomplished mainly by surface complexation, but aggregation of particles may encapsulate sorbed surface species into the multigrain interior interfaces, with significant consequences for contaminant dispersal or remediation processes. Particularly for particle sizes on the order of 1-10 nm, the sorption capacity and surface molecular structure also may differ in important ways from bulk material. We review the factors affecting geochemical reactivity of these nanophases, focusing on the ways they may remove toxins from the environment, and include recent results of studies on nanogoethite growth, aggregation and sorption processes.

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“…Both methods allowed calculation of the capture cross-section as function of the suspension speed and magnetic field strength. However, the steady-state size and shape of the nanoparticle clouds were only found in the limits of flow-dominated (infinite Péclet number) and diffusion-dominated (zero Péclet number) regimes [13,[19][20][21]. Recently, a quite rigorous approach has been proposed by Chen et al [22] who have considered the dynamic growth of the nanoparticle clouds as a moving boundary problem, with the field and the flow fields computed numerically.…”

Section: Introductionmentioning

confidence: 99%

Behavior of nanoparticle clouds around a magnetized microsphere under magnetic and flow fields

et al. 2014

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When a micron-sized magnetizable particle is introduced into a suspension of nanosized magnetic particles, the nanoparticles accumulate around the microparticle and form thick anisotropic clouds extended in the direction of the applied magnetic field. This phenomenon promotes colloidal stabilization of bimodal magnetic suspensions and allows efficient magnetic separation of nanoparticles used in bioanalysis and water purification. In the present work, size and shape of nanoparticle clouds under the simultaneous action of an external uniform magnetic field and the flow have been studied in details. In experiments, dilute suspension of iron oxide nanoclusters (of a mean diameter of 60 nm) was pushed through a thin slit channel with the nickel microspheres (of a mean diameter of 50µm) attached to the channel wall. The behavior of nanocluster clouds was observed in the steady state using an optical microscope. In the presence of strong enough flow, the size of the clouds monotonically decreases with increasing flow speed in both longitudinal and transverse magnetic fields. This is qualitatively explained by enhancement of hydrodynamic forces washing the nanoclusters away from the clouds. In the longitudinal field, the flow induces asymmetry of the front and the back clouds. To explain the flow and the field effects on the clouds, we have developed a simple model based on the balance of the stresses and particle fluxes on the cloud surface. This model, applied to the case of the magnetic field parallel to the flow, captures reasonably well the flow effect on the size and shape of the cloud and reveals that the only dimensionless parameter governing the cloud size is the ratio of hydrodynamic-to-magnetic forces -the Mason number. At strong magnetic interactions considered in the present work (dipolar coupling parameter α ≥2), the Brownian motion seems not to affect the cloud behavior.

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High‐gradient magnetic separation of coated magnetic nanoparticles

Abstract: The feasibility is examined of using high-gradient magnetic separation (HGMS)

Cited by 234 publications

References 22 publications

Magnetic microreactors for efficient and reliable magnetic nanoparticle surface functionalization

Magnetic microreactors for efficient and reliable magnetic nanoparticle surface functionalization

Nanoparticulate Iron Oxide Minerals in Soils and Sediments: Unique Properties and Contaminant Scavenging Mechanisms

Behavior of nanoparticle clouds around a magnetized microsphere under magnetic and flow fields

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