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Magnetic microparticles (MMPs) have been extensively studied and aroused considerable interest in separation science owing to their superior characteristics. In this paper, a novel coated capillary with carboxymethyl-β-cyclodextrin-functionalized magnetic microparticles (CD-MMPs) as stationary phase was constructed and then applied to establish an open-tubular capillary electrochromatography enantioseparation system. The preparation of the CD-MMP-coated open-tubular column was very convenient because the coating of the magnetic microparticles onto the capillary column could be easily manipulated by an external magnetic field. The preparation conditions of the coated capillary such as magnetic field intensity and coating time are discussed in detail. The new constructed CD-MMP capillary system was applied to separate enantiomers of several racemic drugs. Compared to the uncoated capillary system, obviously preferable separations of tested enantiomers were obtained. Several important parameters affecting the enantioseparation, such as CM-β-CD concentration, running buffer pH, organic solvent, and applied voltage, were systematically optimized. Furthermore, satisfactory repeatability and chemical stability of this new CD-MMP capillary system were achieved in the experiment.ᅟ [ABSTRACT FROM AUTHOR]

In this study, pentlandite was selectively separated from serpentine using magnetic coating technology by adjusting and optimizing pH, stirring speeds, magnetic field intensities, and dosages of sodium hexametaphosphate (SHMP) and sodium oleate (SO). A magnetic concentrate with Ni grade of 20.8% and Ni recovery of 80.5% was attained under the optimized operating conditions. Considering the above, the adsorption behaviors of SHMP and SO and the surface properties of minerals after the magnetic coating were studied by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results show that magnetite was preferentially coated on the pentlandite surfaces and sparingly coated on the serpentine surfaces in the presence of SHMP and SO. Furthermore, calculations by Derjaguin-Landau-Verwey-Overbeek (DLVO) theory indicate that the preferential adsorption of magnetite on the pentlandite surfaces is due to the presence of a hydrophobic interaction between the magnetite and pentlandite, which is much stronger than the interaction between magnetite and serpentine. [ABSTRACT FROM AUTHOR]

The conditions and frequency band of reflectionless transmission of electromagnetic radiation through a plane absorbing layer of a magnet that separates two semi-infinite nonabsorbing dielectric media have been found. The dependence of these conditions on the separating layer thickness, magnetic and dielectric properties of the layer substance, and of the adjacent substrate is investigated. [ABSTRACT FROM AUTHOR]

A combination of structure identifying and bulk property experiments were combined with a two-phase analytical methodology to elucidate the influence of a magnetic tape coating process on the substrate polymer film. Employing a typical tape manufacturing process that utilizes coating, drying, and calendering stages, polyethylenete-rephthalate polymer film samples with and without the magnetic coating were prepared. Experiments and modeling studies performed on these samples demonstrate that the drying and calendering processes may increase the crystallinity and noncrystalline orientation of the substrate film. In addition, dynamic mechanical experiments identified a viscoelastic transition at 50 °C for the PET substrate film sample which is near the glass transition of the magnetic coating utilized. Overall, the results of this investigation provide a basis for evaluating structure property interrelations of polymer-based magnetic tapes. [ABSTRACT FROM AUTHOR]