Magnetite beads

The Rhone-Poulenc magnetic beads of wide dispersion in size and, thus, in magnetic content present problems in being able to deplete WBCs from whole blood. Out of the polydisperse distribution of PS-magnetite beads, the small magnetic... 

Micro- and nanobeads with magnetic properties have recently become popular since these tools can be manipulated, e.g., collected in the region of interest. Magnetite nanoparticles are introduced in order to render the polymeric beads magnetic. Preparation and application of magnetic beads will be discussed in more detail in Sect 5.5. 

Precipitation was found to be a very useful method for preparation of nanobeads with magnetic properties [17] since not only indicators but also small lipophilic magnetite nanobeads (having diameter of a few nanometers) can be incorporated inside the polymeric beads. Such multifunctional magnetic beads can be guided to the region of interest, be collected and manipulated there. 

Beads of cross-linked polystyrene containing magnetite crystals (Fe304, a ferromagnetic material) have been prepared and successfully used for solid-phase synthesis [125-127]. The magnetic beads could be readily separated from the reaction mixture with a magnet. 

Fig. 38 Temperature dependence of the relative swelling degree of PNIPA and mPNIPA gels. The molar ratio of the monomer and the cross-linker molecules [NIPA]/[BA] is 50. The magnetite content of mPNIPA gel is 2.1 wt%. The initial diameter of the gel beads was 1 mm...

We have also measured the swelling kinetics of anisotropic samples, loaded with either magnetite or iron particles. Figure 46 shows the swelling kinetics of magnetite-loaded mPDMS beads. The swelling kinetics of iron-loaded samples is also presented. 

Fig. 46 Swelling kinetics of magnetite- and iron-loaded anisotropic PDMS beads in cyclohexane. The filler content is 30wt%, and the cross-linker content is 3.5 wt%, respectively...

Dynabeads are polystyrene beads of uniform diameter (4.5 pm) with a magnetite core, derivatized to bear different functional groups on the surface. Different methods of attachment of DNA to these beads (which can be isolated using... 

Fly ash is composed of tiny spherical and ellipsoidal beads and bubbles of glass, typically containing other phases. Other common constituents are irregular carbon particles, hematite, magnetite, tridymite, cristobalite, quartz, mullite, and spinel. It may contain small amounts of belite, aluminate, and free lime. The RI of the glass is 1.50 to 1.63. 

Reaction with glucoamylase Adsorption onto magnetite Coating onto Sephadex G-50 beads... 

Chitosan/magnetite nano composite beads have the maximum adsorption capacities for Pb(ll), and Ni(ll) at pH 6 under room temperatirre which were as high as 63.33 and 52.55 mg/g respectively. Chitosan magnetite nano composite beads could serve a promising adsorbent not only for Pb(II) and Ni(II) but also for other heavy metal ions in wastewater treatment technology (Hoang finh Tran et al., 2010). 

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