57 research outputs found
Infrared study of biocompatible magnetic nanoparticles
Abstract. Magnetic fluids mainly consist of nano sized iron oxide particles (F
Dielectric properties of nematic liquid crystals with Fe₃O₄ nanoparticles in direct magnetic field
Researched within the frequency range 10⁻¹–10⁶ Hz were dielectric properties
of pure 6CHBT liquid crystals and 6CHBT ones with the impurity of Fe₃O₄ nanoparticles
that have the mean diameter 5 nm and weight concentration 10⁻⁴ %. The study was
performed without and under the influence of direct magnetic field with the induction
0.45 and 0.60 T. It has been shown that the magnetic field influences on the parameters
of the near-electrode area of liquid crystal. In the case of liquid crystal with magnetic
nanoparticles, the parameter changes caused by the magnetic field depend on the
induction value
Morphology and dielectric properties of polymer dispersed liquid crystal with magnetic nanoparticles
It has been shown that introduction of magnetic nanoparticles (MN) of various
shapes with the concentration 10⁻¹ wt.% into polymer dispersed liquid crystal (PDLC)
causes two effects: the size of liquid crystal droplets decreases, and the amount of the
latter with through holes increases. MN increase the effective value of permittivity by
more than one order within the frequency range 10⁻¹⁺ -10² HZ , as well as the electron
and ion components of conductivity. MN reduce the exponent in the frequency
dependence of the electron component of conductivity. The changes caused by the
presence of the nanoparticles quantitatively depend on their shape
Effect of the Molecular Weight of Poly(ethylene glycol) on the Properties of Biocompatible Magnetic Fluids
Microesferas magnéticas à base de poli(metacrilato de metila-co-divinilbenzeno) obtidas por polimerização em suspensão
Immobilization of a Neutral Protease in Magnetic Particles Using Direct Binding Procedure
In a recent study we have found that Bovine serum albumine (BSA) can be bound to freshly precipitated magnetic particles directly by a novel procedure. In this procedure BSA linked covalently to the -OH group of Fe3O4 using Carbodiimide. The binding was confirmed by FTIR spectra and electron microscopy. We have also immobilized several enzymes which have biomedical application using this procedure and confirmed the binding by the above mentioned method. In the present experiment we have immobilized Dispase, a neutral protease using the direct binding procedure. We have found that the protein was bound to the extend of 90% using the dye binding procedure. We have measured the activity of this enzyme by its proteolytic property and showed that it retained 80% of its activity after immobilization
Study of Composites Consisting of High-T Superconductor and Fine Magnetic Particles
The composite systems as a mixture of fine magnetic particles of FeO and superconducting powder such as BiPbSrCaCuO were prepared. The influence of internal magnetic field (generated by magnetic particles) on the superconducting properties of prepared composites were studied as a function of concentration of magnetic particles and their magnetic state. The observed data both of the shielding and the Meissner effect were compared with corresponding linear combination of pure signals of magnetite and superconductor, respectively. The large differences were observed for demagnetized samples. It means that result must be discussed in the frame of the distribution of internal magnetic field created by the magnetic particles
SANS Study of Poly(ethylene glycol) Solutions in
Poly(ethylene glycol) is used for coating of colloidal particles and other surfaces for gaining biocompatibility. Particularly, it can be introduced into magnetic fluids. The aim of the current study was to reveal the structural characteristics of poly(ethylene glycol) in neat using small-angle neutron scattering technique. Solutions of poly(ethylene glycol) (at temperature of 37°C) with different molecular weights in an interval of 400-20000 were investigated. It is concluded that at low concentrations (less than 2% of mass fraction) poly(ethylene glycol) molecules behave as Gaussian coils
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