Preparation Of Core-shell Particles Research Articles

High energy Al@Ni preparation of core-shell particles by adjusting nickel layer thickness

Nickel-coated aluminum powders have attracted significant interest for use as a promising reactive material. Here, nickel layer thickness-tunable core-shell Al@Ni particles were synthesized via an approach combining replacement and electroless plating reaction. The scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), and energy dispersion spectrometry (EDS) were used to confirm that the samples had extremely dense core-shell structure with nickel layer thickness of 120, 160, 200 and 240 nm. The reaction mechanism was also discussed. Additionally, thermal analysis results in the argon environment showed that when the nickel layer thickness was 200 nm, the maximum heat release of the Al@Ni particles reached 1308 ± 6 J/g. These findings indicate that this approach is expected to be applicable for preparing reactive metallic composite particles.

Preparation of Core-Shell Particles Consisted of Polysiloxane and Styrene-Butyl Methacrylate by High Internal Phase Emulsion

A core-shell composite polymer was produced by the method of high internal phase emulsion polymerization. The continuous phase of emulsion contained styrene(St), butyl methacrylate(BMA), octamethylcylotetrasiloxane(D4), and azobisisobutyronitrile (AIBN) which worked as an initiator. The block copolymers with St, BMA, D4 units are particularly promising for surface modification and hydrophobicity. The core-shell structure is proved by the use of Transmission electron microscopy (TEM). In addition, the water contact angle increased with the increasing weight ratio of D4. The results show that the concentrated emulsion system has good stability and the water resistance of the polymer has been improved greatly.

Preparation of core shell particles consisting of cobalt ferrite and silica by sol–gel process

Core shell particles consisting of a magnetic core of cobalt ferrite (CoFe 2O 4) and a shell of silica (SiO 2) are prepared by sol–gel process using tetraethylorthosilicate (TEOS) as a precursor of silica, and metallic nitrates as precursors of ferrite. The core shell structure is confirmed by TEM. The magnetic properties of these nanocomposites are measured by PPMS in low temperature and in different Co-ferrite content. The coercivity is clearly temperature dependent and the saturation magnetization increases with the Co-ferrite content.