[1] Magnetite dissolution, and consequent loss of magnetization, is widely observed in reducing sedimentary environments, where the decrease in Eh-pH values with depth is driven by bacterially mediated degradation of organic carbon. We have observed low magnetizations in sediments with elevated pore water silica concentrations that arise from diagenesis of biogenic silica and/or silicic volcani...

We report the synthesis of Fe3O4@mSiO2 nanostructures of different meso-silica (mSiO2) shell thickness, their biocompatibility and behaviors for loading and release of a model drug ibuprofen. The composite nanostructures have superparamagnetic magnetite cores of 208 nm average size and meso-silica shells of 15 to 40 nm thickness. A modified Stöber method was used to grow the meso-silica shells ...

In this research, mercapto-silica coated magnetite (Fe3O4-SiO2-SH) has been prepared in aqueous solution through a simple approach so called a one-pot process. The Fe3O4-SiO2-SH was prepared in nitrogen condition by mixing magnetite, 3-mercaptopropyltrimethoxysilane (MPTMS), and sodium silicate (Na2SiO3) solution extracted from rice hull ash, and adjusting the pH of 7.0 using hydrochloric acid....

Multifunctional core-shell nanocomposites with a magnetic core and a silica shell doped with lanthanide chelate have been prepared by a simple method. First, citric acid-modified magnetite nanoparticles were synthesized by a chemical coprecipitation method. Then the magnetite nanoparticles were coated with silica shells doped with terbium (Tb(3+)) complex by a modified Stöber method based on hy...

objective(s): enzyme immobilization via nanoparticles is perfectly compatible against the other chemical or biological approximate to improve enzyme functions and stability. in this study lactoperoxidase was immobilized onto silica-coated magnetite nanoparticles to improve enzyme properties in the presence of cadmium chloride as an inhibitor. materials and methods:  the process consists of the ...

Correspondence: Viara Ivanova University of Food Technologies – Plovdiv, Department of Microbiology, 26 Maritsa Blvd., 4002 Plovdiv, Bulgaria. Tel.: +359 32 603622 e-mail: [email protected] ABSTRACT Recombinant cyclodextrin glucanotransferase JCGT8-5 (CGTase, EC 2.4.1.19) was effectively immobilized by formation of chemical bounds on polyethylenimine (PEI)-activated silica particles, on silaniz...

The design of magnetic nanoparticles by incorporation of iron oxide colloids within gelatine/silica hybrid nanoparticles has been performed for the first time through a nanoemulsion route using the encapsulation of pre-formed magnetite nanocrystals and the in situ precipitation of ferrous/ferric ions. The first method leads to bi-continuous hybrid nanocomposites containing a limited amount of w...

Objective(s): Enzyme immobilization via nanoparticles is perfectly compatible against the other chemical or biological approximate to improve enzyme functions and stability. In this study lactoperoxidase was immobilized onto silica-coated magnetite nanoparticles to improve enzyme properties in the presence of cadmium chloride as an inhibitor. Materials and Methods:  The process consists of the ...

objective(s): this paper describes coating of magnetite nanoparticles (mnps) with amorphous silica shells.   materials and methods: first, magnetite (fe3o4) nps were synthesized by co-precipitation method and then treated with stabilizer molecule of trisodium citrate to enhance their dispersibility. afterwards, coating with silica was carried out via a sol-gel approach in which the electrostati...

background: enzymes are well known as sensitive catalysts in the laboratory and industrial scale. to improve their properties and for using their significant potential in various reactions as a useful catalyst the stability of enzymes can often require improvement. enzymes immobilization on solid supports such as epoxy- functionalized ferric silica nanocomposite can be effective way to improve ...