Preparation and characterization of core-shell latexes

Polymeric dispersions with a concentric core-shell structure of the latex particles were obtained by a two-stage emulsion polymerization technique. Conditions for the formation of shells on polymeric seeds are discussed. SANS and SAXS investigations were carried out in order to verify the core-shell structure of the particles. DSC and IR measurements indicate the existence of an interfacial layer between core and shell polymers. The results are transferred to emulsion polymers containing inorganic filler particles.     

Electrochemically decorated carbon nanotubes for hydrogen sensing

Low-density networks of single-wall carbon nanotubes have been modified by palladium nanoparticles using an electrochemical method. A major advantage of this approach is that it allows for selective metal deposition on the electrically contacted nanotubes, whereas the remaining substrate surface and the non-contacted tubes remain essentially unaffected. The Pd-decorated networks function as effective hydrogen sensors enabling the detection of hydrogen concentrations as low as 10 ppm at room temperature. The electrochemical metal deposition scheme is promising for the development of sensor arrays suitable for analysing gas mixtures.