XPS and AFM studies of monodispersed Pb/PbO core-shell nanostructures.

A probe of the core-shell formation and the interfacial properties of monodispersed 30 nm Pb nanoparticles are presented. A direct correlation between the structures of the particle to its chemical states is done, by a careful Ar+ ion depth profiling followed by X-ray Photoelectron Spectroscopy and Atomic Force Microscopy. The study provides a unique insight into the structure of the nanoparticles.

Studying nanoparticles in-flight: applications of size-selected free nanoparticles.

Experimental investigation of nanoparticles in form of free particles in an inert gas is advantageous due to absence of substrate effects. Gas-phase synthesis techniques offer many possibilities for producing and manipulating nanoparticles. The most advanced technique produces well-defined nanoparticles, by means of inert-gas evaporation in a flowing gas, size-selection on the basis of the electrical mobility and subsequent sintering into monocrystalline and quasispherical nanoparticles.

Higher surface energy of free nanoparticles.

We present an accurate online method for the study of size-dependent evaporation of free nanoparticles allowing us to detect a size change of 0.1 nm. This method is applied to Ag nanoparticles.

Determination of coagulation coefficients and aggregation kinetics for charged aerosols.

A new method has been developed which allows determination of the coagulation coefficient of two oppositely charged particles experimentally. For this purpose, quasi-monodisperse particles of different sizes and morphology were used to study the influence of different parameters on the coagulation coefficient. A good agreement between experimental results and the classic Fuchs' theory was obtained when including a method accounting for particle nonsphericity.