Controlling the size of magnetic nanoparticles using pluronic block copolymer surfactants.

We have successfully controlled the size of magnetic nanoparticles by adjusting the surfactant/solvent ratio. Gamma-Fe(2)O(3) nanoparticles of 5.6 and 12.

One-step synthesis of core(Cr)/shell(gamma-Fe(2)O(3)) nanoparticles.

Core(Cr)/shell(gamma-Fe(2)O(3)) nanoparticles were synthesized by mixing Fe(CO)(5) and Cr(CO)(6) in the 9:1 ratio. These particles exhibit narrow size distribution with 13.5 nm as mean diameter and uniform spherical shape.

Doping gamma-Fe(2)O(3) nanoparticles with Mn(III) suppresses the transition to the alpha-Fe(2)O(3) structure.

Here we report on a mixed oxide system, gamma-Fe2O3 nanoparticles doped with Mn(III), where the transition from the cubic to the more stable hexagonal alpha-Fe2O3 structure is suppressed. When amorphous Fe2O3 is heated at 300 degrees C for 3 h, ferrimagnetic gamma-Fe2O3 is observed as the sole product. On the other hand, when the temperature is raised to 500 degrees C, one observes only antiferromagnetic alpha-Fe2O3 as the product.

A new route to alumoxane gel: a versatile precursor to gamma-alumina and alumina-based ceramic oxides.

We present a new route for the preparation of gamma-alumina and YAG nanoparticles. Metal salts of ethylhexanoic acids provide good solubility in hydrocarbon solvents and allow efficient ultrasonication. The sonication product is an alumioxane gel, which can reversibly collapse and reform, depending on the solvent used.

Activity of Candida rugosa lipase immobilized on gamma-Fe2O3 magnetic nanoparticles.

We report the stability and enzymatic activity of Candida rugosa Lipase (E.C.3.